Stop and weight! A 50/50 weight distribution is not optimal

There seems to be more confusion over weight distribution than any other concept of automotive performance. Much of this confusion centers around the marketing hype manufacturers use to sell their cars. For the longest time, companies like BMW advertised that they have a perfect 50/50 weight distribution. This leads a lot of people into believing that this is optimal as far as weight distribution is concerned. I guess this would raise the question: Optimal for what?

The answer to that question would be driving in perfect circles. But as we all know, we don’t drive in perfect circles. If you look at any purpose built race car from the late 1950’s onward, you will find none that have a 50/50 distribution. Virtually all modern road race cars have somewhere between 55-65 of their mass over the rear wheel.  So, having a 50/50 distribution is not ideal as far as performance is concerned, but why?

It should be noted that this information applies only to rear or 4wd cars. Front drive cars do gain some advantages having a forward weight distribution, but their handling dynamics suffer…

I think the part about weight distribution that is generally not understood is how it is just one factor in a cars overall handling and performance. I have explained this in the comments to this post:

The big confusion about a 50-50 weight distribution is that it does not necessarily mean the car is going to have a well balanced feel. There are old muscle cars set up for road racing that have much more weight over the front axle, but if you drove one, you would swear that it handles better than a 50/50 Miata. The difference is, is how the suspension is tuned. Having a good weight distribution to begin with is the foundation for a fast car. But, how that car actually feels in your hands, and how it behaves around corner, is the result of tuning the suspension. With few exceptions, street cars are generally tuned to have understeer regardless of their weight distribution – they are just safer that way. When people tell you a car handles well, they may actually be referring to the tune of the suspension. It doesn’t really have that much to do with the weight distribution or how fast (lap times) the car is.

Let me stress this point again – a balanced feel to the driver doesn’t mean the car can pull high G’s. It just means that the car responds well to drive input and has good dynamic properties; all of which can achieved through suspension tuning regardless of where the weight is in the car.

Racecars actually spend a very little amount of their time in corners; in fact, most of their time is spent accelerating and braking between them. Having a greater rearward mass helps the car do those tasks better. Generally speaking, you always want to keep the weight in a car as far back and as low as possible. Here are some of the benefits of having a rear weight bias:

  • Better braking.
  • Better acceleration.
  • Better corner entry.
  • Better corner exit.

The reason for these benefits is as follows:

Better braking: The Porsche 911 (just an example, could be a GT40 or Ferrari) has always been known for its great braking ability. Many people think its because of their brake technology; but lets think about that for just a moment: Do Porsche calipers pinch Porsche rotors any differently than say Corvette rotors pinch theirs? Probably not. What Porsche does have is their massive rearward weight distribution at around 60%. Having this weight in the back naturally uses all of the tires more efficiently during braking, instead of overloading the front tires which is what tends to happen in a front biased car. Needless to say, the rear brakes do more work on a car that has a greater rear weight distribution.

Better acceleration: With more weight over the rear axle, its obvious that there is going to be more traction. Thus, the car can put down more power without spinning the tires.

Better corner entry: Cars with a rear weight bias will steer quicker and have a natural tendency to oversteer. A slight tendency to oversteer is required for proper corner execution.

Better corner exit: For the same reason given for better acceleration. A car with a rear weight bias can put the power down sooner when coming out of a corner.

Of course, it is possible to have too much rearward weight distribution which causes inefficient use of the tires and bad handling characteristics. For a long time, Porsche was criticized for having ‘bite your head off’ handling. But in those days, look at the tires and suspensions they were working with. The original 911 had skinny equal sized tires on all four corners and a suspension that wasn’t tuned as well as today’s cars. The early 911’s also lacked any type of rear wing or spoiler; the combination of of these three things – heavy rear distribution, skinny rear tires, and lift inducing rear bodywork conspired to give the car the reputation of being a handful. Surely, pushing the car through a high speed sweeper at racing speeds must have taken a substantial amount of skill and courage.

So now you might ask, “Why don’t more cars have a better weight distribution?”, well, in the real world; its hard to make an everyday car like this because it requires moving the engine very far back. This makes for very long front ends and small cockpits with cramped foot wells. This may be ok for a sports car, but is not suitable for an every day car. The other alternative is to have a mid or rear-engine. But those setups also don’t lend themselves to practicality either; and in the case of a rear-engine configuration, engine choices are generally limited to lighter weight engines.  I know the readers of the blog really don’t car about practicality, but car manufactures do. Because in reality, they don’t sell many sports cars compared to their other models. They would sell even less if they were even more impractical. I mean, who would buy a car that you couldn’t even fit a golf bag into!

Food For Thought:

  • Another reason why we see entry level sports cars that have poor weight distributions is because they may be built off of a shared platform. My 350z for instance is shared with Nissan’s (Infiniti) G-Series sedans; a much more practical car. This platform probably has limits on how far the engine can be set back and so on.

Note: I have found this particular post strikes a nerve in many of its readers. It’s amazing how many people have an almost religious dedication to the myth of a 50-50 weight distribution being absolutely perfect. Before you post telling me how wrong I am, please try to think how you first learned that a 50-50 distribution is ideal and if that source was creditable. Also, try to provide some proof or sources to backup your claims. Ad’s are dishonest, and magazine writers typically only have a degree in journalism and are more interested in the ‘feel’ of a car and not the ‘why’ or ‘how’. You should also know that every car that has won a grand prix or Le Mans race has had a rear weight bias since the late 50’s, and race car engineers have never looked back since.

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49 Comments to "Stop and weight! A 50/50 weight distribution is not optimal"

  1. Jake's Gravatar Jake
    June 11, 2011 - 11:44 am | Permalink


    I’ve just bought an adjustable suspension kit for my car and was hoping to achieve a 50:50 weight distribution as I thought this was best. This article has given me quite a fresh insight and has brought to light a lot of things I didn’t realise.

    My car has a rearward weight bias and is mid/rear engined. It’s a smart fortwo and I’m trying to modify it to see what I can achieve. Due to the short length of the car, it could be very hard to catch in an oversteer situation. As such, it’s set up to understeer at the limit. I’ve added massive tyres all round and this has massively affected the cornering speed amd turn in.

    Although you mention a rearward weight balance has all these positive effects, it does seem to still create understeer still at the limit. Many 911’s need to use power to kill understeer on entering a bend. They also seem to be very overtyred to the point they mainly rely on grip over controlled slides due to the weight bias making them hard to catch in an oversteer situation.

    I’m now not so sure as to how to set this suspension up. I don’t want to reduce braking ability or grip, but I also want to achieve a more neutral car which is what I believe a 50:50 weight distribution will give me.

  2. Harry morten's Gravatar Harry morten
    June 7, 2012 - 2:11 am | Permalink

    I read your blog above with interest. I have a problem, which you may be able to help me with. I have a 1928 Bentley with a 200bhp engine, at the front (just behind the front axle) but the car is rather special, in that it is very light – weighing in at 850kg (under 2000 lbs). Problem is that there isn’t much at the back, other than a solid rear axle (with diff) and the fuel tank, while my leaf spring are also quite light, as they have 5 leaves not 9. The car is very skittish on corners, both entry in and exit. Having friction dampers doesn’t help (club regs preventing use of modern telescopics). Any ideas?

  3. Axel's Gravatar Axel
    December 7, 2012 - 9:38 am | Permalink

    Once again it’s me, the motorcycle mechanic. The reason cars and bikes have bigger front brakes is that under braking, the weight transfers to the front thus giving more grip to the front tyres. A rear engined car will not have better braking because of the positioning of said engine.

    • randomperson's Gravatar randomperson
      June 24, 2018 - 5:14 pm | Permalink

      motorcycle dude…

      i dont have a motorcycle but i have a bicycle. on bicycle we have two brakes, front and back. We (us bicyclers) never use the front brake except for emergencies. This is because the front brake locks the front tire and causes the bike to try to rotate and flip over the front. The front wheels lock and you cant steer plus the bike begins to do a “stoppie” (opposite of a wheelie.) It seems unsafe that motorcycles would have front brake dominance. Motorcycles are not much different from bicycles physically speaking.

  4. NOT a 911 Fan Boy's Gravatar NOT a 911 Fan Boy
    January 25, 2013 - 3:26 pm | Permalink

    Dude, I don’t know what evidence you need and how much you have driven a 911 on a track f.e., but some of the statements you make are pretty ignorant. The 911 is a sexy beast no doubt, but the on-the-limit handling is far from perfect. You are talking about fancy suspensions and fat sticky tires and what-not, but the facts are that when you have a 50/50 weight distribution the implied balance of the chassis is perfect even with less than optimal tires and suspension. Porsche engineers are GODS and that’s the main reason the 911 is so successful, but even they are struggling to make the weight distribution of the 911 more evenly spread by moving the engine slightly forward f.e. If you were right (and you’re most definitely NOT) why haven’t other automakers developed cars with engines behind the rear axle??? “The answer to that question would be driving in perfect circles.” That is a pretty ignorant statement. The 50/50 distribution is optimal, because it makes the car’s handling neutral and that is the holy grail! If the car is RWD (with a LSD and it’s 50-50) then the oversteer is built in the chassis itself! Look at the BRZ-FRS-GT86. A car with minimal power and traction is praised all over the world, because of it’s BALANCE. I’m not even going to comment statements like: “Do Porsche calipers pinch Porsche rotors any differently than say Corvette rotors pinch theirs? Probably not.”, which makes you sound simply retarded. The mechanic guy above already told you that that’s bullshit. And don’t know of you’re 12 or something, but next time think a little before writing stupid shit, please. Cheers.

    • FT-86 driver's Gravatar FT-86 driver
      February 10, 2016 - 3:15 am | Permalink

      its funny that you call the author of this blog ignorant while at the same time posting misinformation as “proof” of your argument. the BRZ/FR-S/GT86 does not have a 50/50 weight distribution. it actually has a noticeable front bias. this oversteer characteristic and balance you describe is not inherent the chassis at all. it is an aspect of the suspension tuning. the American version (FR-S) has an oversteer characteristic. which is achieved through a pronounced rear spring rate bias. 137 in the front and 211 lb/in in the rear. this gives that balanced feel and ease of rotation despite the relative lack of power. it is because of this suspension tuning that allows the car to be driven in either a neutral or oversteer manner depending on how the driver manipulates weight transition through corners. without this characteristic of the suspension tuning the car actually tends to push more than remain neutral or oversteer due to the front weight bias. for proof of this look no further than its twin the BRZ which has a front bias spring rate that more closely matches natural frequencies between front and rear based on actual chassis weight distribution. this was done to make the car more stable and predictable over bumps/uneven surfaces. where as the frs has a tendency to act unpredictably over bumps due to the large disparity between front and rear natural frequency. the BRZ is less prone to do so however as it does not have a rear bias spring rate it tends more toward under steer conditions while cornering. this is all of course a perfect illustration of what the author was talking about when he said that suspension tuning can and will provide the balanced feel regardless of weight distribution. so I guess the author should thank you for proving his point with your own example. and before you question my facts/knowledge you should know I have two FR-S/GT86s both of which I race often both when they were in stock form and after I extensively modified them both and I have driven multiple BRZs both stock and modified. my knowledge of that particular platform is both intimate and extensive.

    • BRZ is awful (with automatic transmission at least)'s Gravatar BRZ is awful (with automatic transmission at least)
      May 3, 2017 - 12:49 pm | Permalink

      I’m sitting g in a BRZ. My not liking it is why I am looking at these things. The Porsche has weight behind the rear tires. This causes mechanical advantage in a turn, which causes oversteer issues. Although he did not say it I assume the author was not intending to imply that weight in large amounts actually behind the rear axle would help with turning. You seem to have misunderstood him. He stated that it helps in breaking and accelerating. If I am incorrect I am also sure he will correct me. My BRZ understears badly. I was one of those stupid people who bought an automatic. I am relatively sure that my suspension, and traction control systems are not set up even remotely well for the automatic. I am trying to understand why my car handles so poorly. My guess is that the added weight and maybe a change to the distribution may be responsible, but I still don’t know. I had a Miata before this. It’s body roll was extreme, but it turned and accelerated dramatically better in terms of traction (again in terms of traction) than my BRZ even with it’s upgraded tires. This car does not turn it plows. The guy above explains this as all BRZs, but I just can not imagine they all handle this poorly… This thing should not even be called a sports​ car. Please don’t ask about the stupid transmission. It was a lesson in patience. This is what they had, all that they had that day, and I wanted it right then. I was stupid and impatient. I knew I would regret it, but not this much…

      • ka's Gravatar ka
        May 6, 2019 - 1:37 pm | Permalink

        Inspired by the AE86, the FR-S is designed around the core goal of achieving “Pure Balance,” which begins with the strategic use of the world’s only flat boxer engine in a front-engine, rear-wheel drive configuration. The engine’s compact size and flat shape allow it to be mounted mid-ship and extremely low, giving the car a dynamically favourable front-to-rear weight ratio of 53:47 and a low centre of gravity comparable to some exotic supercars.

  5. NOT a 911 Fan Boy's Gravatar NOT a 911 Fan Boy
    February 11, 2013 - 4:37 pm | Permalink

    Mate, you’re mumbling about how informal I am while adressing your raging negligence. Just chill. You demand someone to prove you wrong with examples and stats, while what you’re stating is, sorry, but a bit daft. Yes, everybody likes Porsches, because they are built like tanks, they’re fast and sexy. The problem is that, they just don’t handle very well at the limit. Yes, they naturally oversteer, but it’s snap oversteer with an anchor behind the rear wheels, that acts as a pendulum. As long as those rear wheels don’t break traction the car is tip-top. The examples that you’re trying to give with rear weight biased racing- or even supercars are reduntant, because those cars are not meant to lose traction (ever). Such cars have such high levels of grip and downforce, that when you eventually go too far, you’ll be traveling at such speeds that you have to be Ayrton Senna (or atleast a very sharp driver) to even have a chance to not crash. When the car has 50:50 W.D. it is balanced and thus handles. Handling (for me) means how the car behaves when you throw it around and make that grip disappear on purpose. Basically when you want to have fun (if you understand the concept). I will try to give you a simple enough example… The GT86 might not be the prettiest or most refined sports car, but what every petrol-head loves it for is the way it handles. That’s because of it’s balance, which in turn is simply the (read carefully) “Perfect” weight distribution. This is handling. I’m not really sure how you came up with the lame pun in the headline or why you thought you were busting automotive myths, but I hope you can accept it now. If you care about how a car feels and how fun it is, you’ll go for balance!!1 Cheers!

    • BRZ is awful (with automatic transmission at least)'s Gravatar BRZ is awful (with automatic transmission at least)
      May 3, 2017 - 1:01 pm | Permalink

      The Porsche has weight behind the rear tires. This causes mechanical advantage in a turn, which causes the oversteer issues you keep referencing. It’s not that the over all distubtion is poor, it’s that a large amount of weight is behind the rear axle. Although he did not say it I assume the author was not intending to imply that weight in large amounts actually behind the rear axle would help with turning. You seem to have misunderstood him. He stated that it helps in breaking and accelerating. If I am incorrect I am also sure he will correct me. My BRZ understears badly. It sucks. Maybe the GT86 is better, but neither is a 50/50 setup. The Miata is, and I wish I still had it instead of this awful thing.

  6. Mike's Gravatar Mike
    July 13, 2013 - 10:05 am | Permalink

    I came here because I’m considering buying a ’93 Mazda Miata. It has a 50/50 weight distribution. My question for Mr. Milmont is “Why do people swear by these cars and their handling” and many claim that they handle better than Porsches and Vettes?” I’m not trying to be a smart ass, I just want a legitimate answer because I’m also considering purchasing a first generation Toyota MR2 with mod engine, obviously more weight in the rear. Thanks.

    • BRZ is awful (with automatic transmission at least)'s Gravatar BRZ is awful (with automatic transmission at least)
      May 3, 2017 - 1:21 pm | Permalink

      I had a second generation Miata. It was awesome for me, however you should know that in stock form it leans hard to the outside of the turn. This did not bother me at all. I was able to go 83 MPH around a 35 mile an hour recommend speed turn where in the BRZ I could only go 67. The BRZ understeers the Miata really didn’t. Also I believe because of how soft the suspension was it would have noteworthy balance changes off from 50/50 when accelerating or breaking hard. I just didn’t have any complaints from these things as everything was very predictable in that car. I have ridden in an old MR2 it didn’t seem to have much lean in the turns compared to my old Miata. If that is important to you it’s something to keep in mind. My BRZ hardly rolls at all in a turn, but comparatively it also doesn’t turn at all, so there’s that as well… Both were bone stock.

  7. Beka's Gravatar Beka
    August 18, 2013 - 3:10 pm | Permalink

    The article is wrong.
    First of all good weight distribution is a starting point. If it is flawed, no matter how you try, you will never be able to make the setup as perfect as with correct weight distribution.
    Too much rear bias is horrible thing. It has no stability in rear under braking and has horrendous inertial and off-throttle oversteer. The original poster talks about acceleration out of the corners but does not talk about lateral G forces which the heavy rear is unable to handle and loses grip.
    Porsche had to fit excessively large rear tires and introduce AWD to somehow balance the car. As a result it develops understeer in slow corners where lateral G is not high. In road cars this might be a lesser problem as manufacturers are not limited with the size of tires they can use, but racing categories are limited, therefore weight distribution is a huge factor.
    Perfect distribution is somewhere around 45-55 rear, with dampers, springs, anti-rolls and camber all tuned accordingly after the distribution is correct.

  8. Beka's Gravatar Beka
    August 27, 2013 - 8:41 am | Permalink

    John, I again disagree, the assessment of porsche is: they are fast inspite of their weight distribution, not because of it. Porsche is constantly trying to improve its balance by moving the engine to the front slightly. You can look for that information if you dont believe me. 911s still have rear engine layout because this is a tradition and the history of the 911 brand. If porsche decided to build a competitor for 911 around a car like cayman and gave same same amount of resources, materials and time to it, it would have ended up being a significantly better performance car than 911.
    When Porsche built an ultimate supercar (carrera GT) they put the engine in the middle, not behind rear axle.
    All I want to say is that Porsche designer themselves know that 911 is not that perfect and they are trying to alter weight distribution themselves.
    I drive a single seater with 40/60 rear weight bias which is the result of a heavy engine and it is horrible. I’m moving the battery to the front for the very same reason, this is how i found your article.
    Generally I would agree that 50/50 is not a perfect distribution but I dont agree with the general pathos of the article which seems (at least to me) to claim that putting nearly the whole weight in the back is great, or that something like 30/70 rear bias is a cool thing when it is not.

  9. Beka's Gravatar Beka
    August 29, 2013 - 5:17 am | Permalink

    Porsche has been doing this since 60s
    here is the first link, read the paragraph on B series:

    And a 2012 911s. Prosche designe a whole new, shorter gearbox to do that.

    Porsche is moving closer and closer to 50/50 and it is not becoming slower by any means.

    My single seater is Formula Alfa (not boxer) with a 2 liter TS engine. It was a mono series in Russia under the same name. you can not adjust the shocks (damping, rebound) and install different springs but tweaking camber, toe etc is obviously allowed. It is a slicks and wings formula and aero is also adjustable. I took this car to compete in local national mono series.
    I had another single seater which we restored, it was a 1986 Estonia 21M, which was being built in Estonia in 80s for a USSR Formula 3 championship. That was a different car, with 80s style driver positioning (driver sitting in the front, engine closer to rear wheels). It had much better balance than my current car despite being a 20 year older design, it gave much more confidence, was more stable under braking, better over kerbs (which is not only because of balance) and you could attack harder. Unfortunately I did not drive it a lot and it was not even set up properly but despite that I felt more confident in that car.

  10. igor's Gravatar igor
    September 25, 2013 - 10:46 am | Permalink

    why do you think that a rear weight bias gives the tendency to oversteer? it’s the other way round…

  11. Radek Jarecki's Gravatar Radek Jarecki
    October 12, 2013 - 2:10 pm | Permalink

    Not quite. Newton laws will be responsible only for weight transfer.
    If we move some mass to back of the car, rear wheels will need to work more in corner. But igor may say:, ok they need to work more but they are more vertically loaded so they have more grip. Well, that would be true for a box of bricks, not rotating tyre.
    Tyre friction coefficient changes nonlinearly with vertical load. For the twice load, you don’t get twice more lateral grip.

    Let’s consider a car with rolling stiffness equal on front and rear. In 50/50 weight distribution, weight transfer is equal for front and rear. So front and rear grip the same.
    When we have more mass, we have more weight transfer on rear than front.
    So we have bigger difference on rear tyres vertical load than on fronts. Let’s say, in the corner, FL load is 200kg, FR is 100kg, RL 500kg, RR 200kg. Front weight transfer is 50kg, rear is 150kg.
    So you can see that vertical load difference between RR and RL tyres is big. Tyres always will work less efficient when loaded unevenly. So front is more efficient than rear in case of rear weight biased car. That’s why it will oversteer.

  12. martin's Gravatar martin
    January 16, 2014 - 9:58 pm | Permalink

    I think this will help clear up that question…..

  13. Jared's Gravatar Jared
    February 17, 2014 - 7:37 am | Permalink

    Great discussion. I think the original post and a lot of the commenters made logical points. This the way I see it. Maybe engine layout in a racing application is also the result of practicality than simply weight distribution. No driveshaft, transaxle, less overall component weight. The resulting weight distribution, that creates larger moment forces in the rear, is both engineered out by tyres and suspension, as well as an adjusted driving style. Trail brake, mid to late turn in. Nose tucks quicker (lighter front), gets pointed faster, you get to hit the gas sooner.

    I don’t think there is really such thing is an ideal weight distribution, because it depends on your (adapted) cornering technique. (Be forewarned, there is no scientific data ahead. This is purely conjecture based on reasoning).

    The goal is to navigate the corner in the quickest way possible (duh). In order to do that, we should (must?) maximise lateral grip. To achieve the highest lateral G-force, we must load the outside tyres equally front-to-rear. An uneven front-to-rear weight distribution mid-corner means that we are overloading one of the outside tyres more than the other, and thus wasting grip of the less-loaded tyre. A 50/50WD MAINTAINS that 50/50WD under neutral, steady-state cornering. This is probably the best way to navigate a corner in a 50/50 car (with respect to even loading of outside tyres). In a forward-biased car (rear drive), a steady-state corner would maintain the forward bias, but putting power down correctly through the corner, would shift the weight toward the rear, bringing it closer to 50/50. This is ideal for my driving style, as I like to brake early, turn in early, and start the car rotating, and power through the corner. When done correctly, the car feels balanced.

    The same can be said of rear-biased cars. To get the most out of them, it’s best to trail brake (to keep the front loaded into the corner), get the car pointed asap to the exit, and then power down when straight. If you swap driving styles, the forward-bias car will drive straight into a tree, and the rear-bias car will spin sideways into that same tree. Different WD, different driving style, different application.

    The concept of an ‘ideal’ weight distribution assumes an identical approach to the corner, in this case, a steady-state corner. I suppose 50/50 is touted as ‘ideal’ in that from that neutral balance, you can access more of each style of cornering.

    Rebuttals welcome. I am not a professional driver or a mechanic or a race engineer. I just like to drive 🙂

  14. March 10, 2014 - 8:36 am | Permalink

    According to Porsche (we believe them) the optimum weight distribution for a sport / race car is 57% in rear axle and 43% in front axle.

    All the Porsche Le Mans winners of the past (917 – 908 – 956 – 962 – 911Gt1) had this balance distribution.

    911 approaching this distribution too. Year after year with new editions.


    For super cars and race cars, the optimum weight distribution is 57% in rear and 43% in front axle.

    Of course 50 – 50 is wrong.


  15. Barkev's Gravatar Barkev
    April 30, 2014 - 10:13 pm | Permalink

    I have a 400 hp Austin healey sprite E modified built for autocross. Weight dist 47/53 front/aft. 80 inch wheel base.Amazing handling but its handfull to drive!only wish that the wheel base was much longer as it switches from under-steer to over steer rather quickly ! thank god for the 6 degree + caster in the front that centers the steering when i remove my fingers from the wheel for a Milli second! and saves me every time!! Since the engine is supercharged, i also have to watch it as when to release the throttle the rear wheels engine break when i do so and the car goes to a snap over steer!My other car that i am going to use as an example today is my VW scirocco quattro. It is 530 hp space frame and uses the audi quattro drive train. weight distribution 67/33 front aft so we can see it is nose heavy! believe it or not this thing does not never ever ever understeer!! when i lock the center and rear diff it is the best handling car! i did a mistake and installed a gearbox with a torsen center diff and the car became a disgusting under steer monster! These are examples of cars from both extremes and as we can see it is the setup of the car that matters the most not the weight distribution as people think.Alignment,Diffs,for/aft height,fore/aft tire size,break distribution,power delivery and other setups are what matters the most!some examples of Cars that i have, had Porsche 914/6 GT (excellent fast corners,not so good slow corners) Renault 5 Turbo 1 ( off boost understeer,onboost oversteer) and every other car you could imagine from a prodrive prepared impreza rally car to a Mini 1275 GT! My personal favorites were my 1971 2.2 Porsche 911 E! That thing handled like a dream! once the front was lowered slightly more then the rear ( as with the r5 turbo1)!My other favorites were my Renault 5 GT turbo! This FWD monster has an amazing amazing handling! so were the fully lightened and modified evo 5 RS and impreza GC8 that i autocrossed and hill climbed them! they were both nose heavy but the center diff sorted it out and the things were glued to the ground. 50 – 50 is more of a psychological sale strategy as the average human being always feels that equal is safe and perfect while in fact it does not matter at all!

  16. Callum's Gravatar Callum
    June 10, 2014 - 7:41 am | Permalink

    Excellent article. As to the replies above asserting that a 50-50 weight balance is optimal, I have a 1990 magazine article comparing fast cheap cars cornering speeds. All the data is properly logged, with speeds at entry, apex, exit and overall times. The cars judged to hamdle the best were the MX5 (not suprising) and Ford Laser GTX. The Laser isn’t even close to a 50:50 weight distribution, but was a close second to the perfect 50:50 MX5. The FASTEST car of the lot tested though, was the SW20 MR2. It was extremely snappy and quick to bite at the limit, but leagues faster than its nearest competitor. I’ve seen a few of these in action at trackdays, and remember watching one battling an S14 Silvia, a car much closer to 50:50 than the MR2. The Silvia was faster in a straight line and had much better brakes, but every single corner would see the MR2 pulling out a few metres lead on exit.

  17. Anson's Gravatar Anson
    July 25, 2014 - 7:41 pm | Permalink

    I’m a student in mechanical engineering and we covered pretty much what was said in this article in one of our earlier physics course. Essentially everything that was mentioned by the author is spot on. I also found it humorous that some posters are essentially yelling that “OMG GT86 HANDLES SO WELL BECAUSE IT’S SO WELL BALANCED BLAH BLAH BLAH.” First of all, you have no idea what you are talking about. They are just regurgitating what they read in the magazines. You are not an expert nor are you educated enough to comment on said topic. Second, the laws of physics do not change. The engineers are the ones that design and change certain aspects of the car (tires, suspension, aero, etc) in order to make the car more “balanced”. Third, don’t get so butthurt because your supposidely “well balance 50/50 car” isn’t actually ideal physically. If your car is so great, there is no need to defend it.

    You can make a car that is FR handle as well as a MR. No where does it say that a car that is 50/50 is bad. The author is not arguing that point. But all things being equal, the MR is the ideal layout because of SCIENCE. I think it is best if some of these posters actually pick up a physics books rather than a car magazine and learn a thing or two.

  18. RACER LUKE's Gravatar RACER LUKE
    February 3, 2015 - 5:58 pm | Permalink

    I think there is a point of this that everybody seems to be overlooking. The majority of cars have the engine in the front, and of course the drivetrain too. Sports cars tend to have the diff in the back of course, which shifts some of the weight back, but in essence most real world cars are naturally weight-biased in the front. Where BMW and Nissan have an advantage is their engines are located behind the front axle so the near 50/50 distribution is of course much better than a 60/40 front bias. It may be more advantageous to have 55% rear but in reality this is not achievable for a practical 5 passenger vehicle so 50/50 is the closest we can get to perfection without sacrificing practicality

  19. Wes's Gravatar Wes
    February 19, 2015 - 8:17 am | Permalink

    The first time I learned about the 50/50 ideal was an article on BMW Films, the ones with Clive Owen and various other celebrities. It was quite convincing, and I believed it for a good 10 years. In the past year, when I finally started going to the track, I began to have my doubts. A little googling led me to your article, and you couldn’t have put it more clearly. 50/50 is predictable and balanced, but by no means the ideal.

  20. Alex's Gravatar Alex
    March 20, 2015 - 5:15 pm | Permalink

    This post is old and I’m late to the party here but would appreciate a response…

    What about center of gravity? So lateral load in corning would be disproportionately put on the rear. The Physics 101 version would say that the extra weight back there cancels this out but in reality it’s not so linear. Hence the extra tire width out back, I’m guessing. Additional, a stiffer roll bar would be required out back, no? Not sure what this does to some of the turn-in dynamics.

    Admittedly, I drive both an E85 Z4 and a Spec Miata on the track so I’m apparently biased. 🙂

    But speaking anecdotally, the 50/50 weight and the slight steady state (aka skippad) minor understeer seem to translate well on the track. On entry, mild trail braking turns the car into a mild oversteerer and helps turn in. Once I’m back on the throttle, the power to the rear again turns the car into a mild oversteerer as I throttle steer to track out.

    Any thoughts?

    Great article!


  21. Mike Clarke's Gravatar Mike Clarke
    April 15, 2015 - 6:55 pm | Permalink

    Having the great majority of the vehicle mass in between the front and rear axes would have to be the most important thing to achieve if you want great handling, followed by weight distribution – 50/50 is good. As for having more mass at one end to assist acceleration/braking, that defeats the above. Remember also that static weight distribution changes dramatically under acceleration/braking. Eliminating weight overhanging the front and rear axes, and using throttle and brake pedal properly will solve many issues.

  22. Jay's Gravatar Jay
    April 20, 2015 - 7:29 am | Permalink

    Those touting ’50-50 is always better’ are so silly. Suppose you have a variety of RWD vehicles and to simplify (and to better understand what issues you’re actually dealing with) you are doing separate testing of acceleration-traction, braking-traction,and cornering-traction. I guarantee you’ll find that in hard-acceleration traction testing, extreme rear weight bias is best. In fact if you’re not cornering you want 99.9% of the weight on the rear wheels AT the time of acceleration. (This does not at all mean 99.9% rear weight bias because acceleration un-loads front wheels). Now let’s test braking traction. On a vehicle (I’ve tested it on my bicycle but this would apply the exact same way on a four wheel vehicle if it had such a high center of gravity) IF you pitch 99% of the weigh forward to front wheel, you need to stay off the rear brake. Likewise, if you could get the bike to have 50% of the weight on the front wheel 50% on the rear DURING extreme braking that would be ideal for braking traction using front-rear brakes (assuming identical tires front/rear). Now let’s talk cornering at steady speed: of course 50-50 is best for a bike or car assuming tires are identical.

    Every car is making compromises to try to get pretty close to these ideals but may prioritize one (say, acceleration) or another (steady speed cornering) and also might prioritize stuff like seating space

  23. ChassisMan's Gravatar ChassisMan
    July 6, 2015 - 11:05 am | Permalink

    I’m so glad somebody chimed in about the actual handling characteristics of a 911. Every statement made in favor of more weight over the rear cited the 911 as evidence in favor when in fact the 911 is the PERFECT example of more weight over the rear being a problem. 911’s brake well because all that weight over the back allows them to have a larger deceleration force in the rear than typical cars have which keeps them from rotating while braking. And of course, as the 911 illustrates perfectly, the larger rearward mass has a tendency to cause the car to rotate while acceleration out of a turn.

    In closing don’t setup your car based on advice from people who may not know anything about physics at all. A perfect example is the post directly above mine from professor Jay and his bicycle. He suggests we want ALL the weight on the back while accelerating which is the definition of a drag car doing a wheelie. The front tires can’t steer the car if there’s no weight over them for crying out loud!!!

  24. Per's Gravatar Per
    August 31, 2015 - 2:19 am | Permalink

    Only those not clever enough to do the math for themselves will argue that 50/50 is always the ideal and that this is why the mazda miata is such a nice car. Meanwhile they are unable to explain why 50/50 was not done for most Ferraris, Lamborghinis, Lotus’…

    Porsche aren’t moving the engine to change the weight bias. They’re working to reduce inertia which is the big drawback to having the engine stick out beyond the wheel axis.

  25. Marc Lewis's Gravatar Marc Lewis
    September 9, 2015 - 1:40 am | Permalink

    In kart racing, 48/52 or 47/53 is the preferred bias.

  26. Alex's Gravatar Alex
    November 16, 2015 - 2:24 pm | Permalink

    Hi John,

    I read your great article with much interest and i truly understand all the information given in it.

    question ( how i got to this article in the first place): i am researching to find ‘the perfect foundation’ car. There are a number of constraints that i would like to state here.

    1: the above mentioned slightly aft biased weight distribution
    2: rear wheel drive
    3: four(ish) seater, preferrably smaller to medium sized hatchback so i can bring a mountainbike in the boot.
    4: well below the 10k $ mark (I have other passions besides owning a fast streetcar ;-).

    5: not a gas guzzler during normal rides.

    It can be old(ish) but preferrably something that isnt too exotic in my part of the world (continental europe). In case parts and upgrades are needed.

    My plan is to slowly upgrade this ‘foundation’ into a solid fast street and maybe trackday machine.

    Hopefully i will harvest some interesting feedback here.
    Thanks in advance.


  27. Steve's Gravatar Steve
    March 16, 2016 - 1:12 am | Permalink

    I feel the correct information on this topic is long overdue. You have to be living under a rock to miss the traction advantage the 04 Ford GT had over contemporary Vipers. And adding more horsepower to either car made it more obvious. If 345 tires aren’t enough, perhaps the engine needs to sit closer to them. On a similarly rebellious note, the universally taught apex technique is wrong. Consider straightening the record on that too if you enjoyed writing this article.

  28. John's Gravatar John
    December 6, 2016 - 11:31 pm | Permalink

    Praise to you John for trying to explain why 50/50 is not optimum.
    Unfortunately, alot of rev/gear heads are simple, stupid people.
    Probably religious.
    They have no idea what they are talking about, but want to sound cool.
    People if you think 50/50 is optimum, do us all a favour and end…

  29. Dre's Gravatar Dre
    June 7, 2018 - 4:15 pm | Permalink

    The original article is shockingly accurate from a physics and engineering perspective. I don’t think I’ve ever read something on cars that Isaac Newton himself would understand and approve of, until this. A few notes, comments:

    Porsche knows how to make cars. The weight distribution of their race-winning cars (cited above) should be more convincing than that of the 911. The 911 (I’ve driven one for 20+ years) was initially designed as a compromise. They knew that a mid-engine (engine in front of the transaxle, rather than behind it as they did on the 911) layout would perform “better.” And as the author clearly pointed out, “better” involves many things, including accelerating, braking, handling feel, and actual handling performance.

    But Porsche wanted the two small rear seats in the 911. That’s why it’s rear-engined. Battery in the front trunk, suspension tuning, wider rear tires, etc. all are making up for this excessive rear bias. And now it is an iconic design/brand, so they’re sticking with it as their flagship (after trying to phase it out and replace it with the front-engined, water-cooled, V8-powered 928 in the 80’s-90’s).

    Porsche can make things work. So that’s why they invented the rear transaxle on their front engine cars, to keep weight balanced, ending up with close to 50/50 in those compromises.

    For those interested in understanding the physics, a perhaps useful concept is that if the chassis can be assumed to be rigid, all the mass properties boil down to the mass, center of mass location, and moment of inertia (matrix). So there is nothing special about where exactly the mass is distributed; it only matters how these basic properties are affected.

    And to go along with that, a suspension tuning kit might change the handling, but it won’t significantly change the weight distribution unless you put it in the trunk and leave it there. Corner balancing may change the weight on each wheel, but does not change the overall front-rear or left-right mass distribution.

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