why is RWD better than FWD?

can someone tell me why is RWD car better than FWD car??
what's good and bad about RWD? and what's good and bad about FWD?

well usually rwd cars have a btter balance for once

second while drag racing under acceleration the weight is shifted backwards so the drive wheels in a RWD car get more traction

thirds if you floor a FWD car in corners and brake traction you'll understeer while if you do the same in a RWD car you'll generally oversteer

what changed my ming about getting a RWD car is autox...because i try to accelerate out of courners very early it causes my car to understeer badly.....basically for me autox is a constant fight to push the car to its limits(aka fighting some very bad understeer)...so soon i'll be getting a 350Z

In a modern car the differnce is minimal, and in something like a small car the extra power loss through a RWD driveline can make FWD a lot better, but generaly a FWD gives the Front wheels extra work cornering under extreme conditions (racing).
In a RWD car the front wheels can work on steering the car, while the back wheels work on acclerating it.

There is some advantage to be had regarding weight transfer under accleration, but only on cars with very very high hp numbers.

push is better than pull.... :smokin:

Great answers by Neutrino and Moppie above http://www.automotiveforums.com/vbulletin/images/icons/icon14.gif I would like to remind you that there are positives and negatives associated with each driveline type, so there is always a trade-off when choosing one over the other.

As far as drag racing, in my opinion when you break into 700 to 800 whp territory, two cars, same engine and horsepower, same weight, same level of driver skill, etc. in each, if all things are equal except that one is FWD and the other RWD, the RWD car should post a quarter mile time approximately one half second faster than the FWD car. As Moppie said, you need to have some serious power going to the pavement for this to make a tangible difference in this respect.

In snowy conditions, FWD is generally prefereable for making traction over RWD. There are exceptions to this, like the traction control system that BMW has been using since 1995. In winter condition testing a few years back, a 3-series BMW with traction control was able to outperform several FWD and AWD cars in a track test focusing on handling and maneuverability in snow and ice conditions, including a FWD Volvo sedan (also with traction control - I forget which one), and a Jeep Grand Cherokee with part time 4WD. But that is of course the exception, not the norm. RWD cars can exhibit a tendency for the rear wheels to fishtail to one side if they lose traction. FWD cars are much more predictable in handling, and easier to "recover," if their drive wheels break traction.

I agree with Moppie's comments about how the gap between the two is shrinking. Not too long ago, Car & Driver tested an Acura 3.2 CL Type S with a six speed manual transsmission, fitted with a helical limited slip differential (http://auto.howstuffworks.com/differential6.htm) from the factory, and they swore that they could not tell that it was a FWD car. A limited slip diff. does a good job of sending extra torque to the outside wheel during a turn, helping the outside wheel rotate faster than the inside wheel, which diminishes understeer. I can vouge for that with my car too (Integra GS-R with Quaife LSD), especially at low speeds, where I swear that at WOT in second gear going around a turn, I can almost push it to where the car feels like it is ever so slightly oversteering.

I would also likle to add that for the motoring public of the world, understeer is safer than oversteer. Having to correct your steering going around a turn by turning sharper is easier to do and more intuitive than correcting by rotating the steering wheel back closer to center.

JD and Moppie have very good points........


i would also likeconcur with JD's post that for handling the best LSD's are the helical type(quaife in particular).....the clutch type has a bad habbit of locking the wheels togheter and causing understeer and the viscous type can be overpowered by a combination of very sticky tires and good engine power

how is it easier to regain control for a FWD over a RWD? your tellin me that if your spinning out in a FWD you can recover easier then spinning out in a RWD? no way. while your spinning in a circle, your drive wheels is tryin to steer and acelerate and brake at teh same time. where as with a RWD, you can counter steer and input throttle to correct the spin out. the main thing is, its harder to spin out in a FWD. so its more dummy proof. its harder to ulitmately lose control for a FWD ( spin out) however it is quit easy to understeer. most of my friends drive FWD's such as tegs, and preludes. and they always understeer. where me, i can modulate my steering with my right foot on the gas pedal. for a RWD its easier for a noobie to fuck up and crazy, such as in the rain and stuff. however, it gives you the more control over a FWD. i have recovered from alot of stuff in my S14 and if it was a FWD, those fuck ups probrably would've never happend but if it did, like my friends 97 v-tec prelude, it would've been wrecked from a spinout. ( like my friends 97 v-tec lude)

FWD=Torque Steer :shakehead RWD=Ability to drift! :iceslolan

First off, in reguards to some of the previous posts:

Torque steer, was common on the very early fwd cars, but by the mid 80's it was no longer a factor for most cars, and today only shows up on the highest powered fwd cars.

Regaining control, in a fwd car from a skid is the easiest of all the platforms, some (stupid) people make the mistake of jabbing the brakes and lifting off of the accelerator, keep your foot on the gas, and point the car where you want it to go - and it will go there.

Then there is the matter of understeer. Alot of people seem to think that understeer for some reason is a trait of only fwd cars, and not just front engined cars in general. The matter of the fact is, that most modern fwd cars understeer less than their rwd counterparts of the 70's and 80's. Understeer is a common trait of practically ALL cars with a front weight bias. Indeed, Car and Driver, and Road & Track both comented that the FWD 1980 Corolla-Tercel understeered less than the rear wheel drive toyota's (even the Celica according to Car and Driver) of the same year.
Certain early FWD cars, notably the early SAAB 92, had very bad oversteer problem, so dangerous in fact that SAAB had to redesign the rear suspension system for the 92.

So why then when the worlds most perfect platform already existed (rear engined rear wheel drive:)) did the French decide to put the engine up front, and keep the driving wheels in the back? Simple, in the 1890's Panhard Levassor wanted all the passengers in the vehicle to be facing forwards, when the engine was previously mounted in the center of the vehicle, the rear seat had to be mounted facing backwards, but with the engine up front, that valuable foot space in the center of the vehicle was free, and the rear seat could now also face the same direction as the front seat. Isn't that grand? Eventually, Panhard dropped rwd in favor of fwd - how interesting.

Personally though, I think that the rear engine layout is the best, you've got all the works at one end (so power transmission is as efficent as it is in a FWD car, and as space saving) You've got the weight of the drive train over the drive wheels (Like in FWD) making for good traction through snow and ice, but unlike FWD you don't have to complicate everything because your driving wheels don't also steer the car. I'm surprised the the rear engine layout isn't being used in more cars these days (we can blame Ralph Nader and the Corvair for most of this problem) :biggrin:

how is it easier to regain control for a FWD over a RWD? your tellin me that if your spinning out in a FWD you can recover easier then spinning out in a RWD? no way.


When your old enough and experianced enough at driving enough of each drive type you will see how it works.
Its all about weight transfer, and moments of intertia.

Otherwise everything 2strokebloke plus a little more:

Torque steer occurs on any car where the axles are of an un-equal length, it dosnt mater if its FWD or RWD. Its a problem on high powered MR2s, and even some 4WD's when fitted with very large engines can be made to squirm if they are fitted with an off set diff.
The infamous Skyline GTR even suffers from it to a very small degree under very hard launchs as the frount diff is off set slightly to one side.

Most powerful FWD cars now days get around the problem by useing an intermediate shaft, which places an extra piece of axle inline with the gear box out put between the gear box and the final drivng axle on the longest side. All three axle lengths are then weighted to make sure both sides are balanced, and if done properly there will be zero torque steer.
From what I can tell Honda were the first to put it to use in a transversly mounted FWD car, being the B series powered Preludes.
Of course a FWD car fitted with an inline engine and a transaxle already has equal length drive shafts.

Thank you Moppie and 2SB.

TatII, you do raise some legit points. It is true that you gain a certain element fo control in having the rear wheels for power, and the front wheels to steer/bear most of the burden of braking. However, you pretty much answered your own question: how is it easier to regain control for a FWD over a RWD?
Most auto manufacturers build relatively utilitarian cars for the masses, so they are generally working down to the lowest common denominator of driver. Hence, the ubuquitous automatic transmission, particularly in the USA (I would estimate, off-hand, that 95+% of all cars in this country have automatic transmissions). Additionally, car manufacturers also take the proactive approach of trying to reduce the incidence of automobile accidents by making cars that, as you said: the main thing is, its harder to spin out in a FWD. so its more dummy proof. its harder to ulitmately lose control for a FWD ( spin out) however it is quit easy to understeer.
And there you have it. For more experienced drivers, a manual transmission gives you much more control over your car than an automatic. But, you have to be skilled and experienced enough to do it. For those not as experienced, a manual transmission IMO makes you more of a potential accident. And I'll agree half way with that point for RWD cars. If you travel up to a climate where they deal with snow and ice for a significant portion of the year, drive train layout strongly indluences vehicle selection, and you will see that FWD is much much more popular than RWD. You can argue with this all you like, but I stand by this.

One more thing. I think you may be over-emphasizing the potential danger in a car that understeers. I will not repeat myself (see previous post (http://www.automotiveforums.com/vbulletin/showpost.php?p=1158809&postcount=5)). Understeer is safer than oversteer (i.e. for the lowest common denominator of driver). Besides that, Mops has deflated the issue of understeering characteristics as they purporedly pertain to drive train layout. And, I would also like to add that just like in a RWD drive, you can modulate your steering with throttle application in a FWD car as well (if I am understeering a little going around a turn in my Integra, I can let up on the gas a little, and without moving the wheel, I can correct the turn).

well i never said that i think the RWD layout is the ultimate layout. i hate it in the rain, and its impossible to drive in the snow. so for those situations i would definitely choose the FWD layout. but of course i would prefer to have AWD for those situations.