Reading automotive magazines and car review websites, one gets a general sense that those who consider themselves car aficionadios consider rear-wheel drive to provide superior handling over the now-nearly-ubiquitous front-wheel drive. Why is this? The only answer I’ve ever heard involves a concept called torque steer, but I don’t understand it very well. I can’t say it’s something I’ve ever noticed in my front-drive cars. Is this really a real-world difference, or is it something one is likely to encounter only when driving under track conditions? Are there any other reasons?
(I’m placing this in General Questions because I’m hoping there are are objective answers as to why “car guys” think rear-wheel drive is better.)
lack of torque steer. Torque steer is a phenomenon in FWD cars where acceleration can cause the steering to pull to one side, or try to straighten itself while turning. You aren’t likely to notice it much in a lower-powered front driver, but when you get up to higher performance vehicles it can be a real problem. I notice it in my SRT-4 when under hard acceleration, and the MazdaSpeed 3 is/was a well known torque-steering monster.
easier to get close to a 50/50 front-rear weight distribution. getting close to 50/50 means you have more flexibility in tuning the car’s handling characteristics, as opposed to a nose-heavy FWD car basically doing nothing but understeering at the limit.
more flexible front suspension setups. FWD cars almost always have MacPherson struts up front, which almost never offer caster adjustment and often times have no camber adjustment either. RWD cars can have traditional upper/lower control arms up front.
none of this is to say you can’t make a FWD vehicle handle well, though.
I was going to pop in and mention this, as I have (and love) a 'Speed 3. It’s definitely a thing, though not something I notice much day to day. If it’s just straight line acceleration, what I’ll tend to get is a little wiggle in the steering wheel in first and second gear. Where it becomes an issue is when, for whatever reason, I’m combining hard acceleration with a turn. For example, I was making a left hand turn onto a divided roadway. I was still in first gear, as I’d started from a stop. I gave it a bit more gas than I’d really intended to–and nearly wound up pulling a U-turn. (Well, that’s how it felt; in reality, I caught it in plenty of time.)
I’d say this is a main reason petrolheads like RWD. You can get the back end to “step out” around corners in a controlled slide, which many of those in possession of Y chromosomes tend to find quite fun. Probably not too applicable to your everyday driving, but check out any local roundabouts around pub closing time…
Used to have a Nissan Maxima, a FWD car. I never noticed torque steer, but I did notice wretched understeer when accelerating in a turn, as well as the wiggle/wander during straight-line accel that LawMonkey mentioned. In addition, the weight transfer from front to rear during acceleration left the front tires barely capable of keeping a grip on the pavement during straight-line accel in first gear, even in the best of traction conditions.
This spring I switched to an Infinity G37 Sport, a RWD car. All of the aforementioned nonsense is gone: no wiggle under acceleration, understeer is gone (the tradeoff is that the back end will step out if you get on the gas way too hard), and the weight transfer from front to rear during acceleration means that the rear tires have all the grip they need to prevent slippage on dry pavement. I love it.
FWD enthusiast here. Going to use your post here as a jumping off point, if you don’t mind.
There are suspension and drivetrain tricks that car companies can use to mitigate, but never eliminate, torque steer. Most FWD cars don’t use them because they cost money, and at certain power levels (like the Mazdaspeed3) they can only do so much. Torque steer is something you can get used to, but there’s always that feeling that you’re fighting with the car, and car guys don’t like to fight with their cars, unless they’re defending a GT500, in which case they praise the aggressive feeling it gives them.
50/50 weight distribution allows a car to make the most of the tires that are typically under it. If there’s more weight on the front wheels, logic would dictate that the front tires should be wider to compensate, but you almost never find that, and most rulebooks won’t allow it (whereas staggered setups that favor the rear are common.) All things being equal, a car with a 50/50 weight distribution will be able to out-turn a car with a 60/40 weight distribution because it can use more of the available rubber for turning the car, whereas the offset car will burn up the front tires and under-utilize the rears. This is why 50/50 is a good thing.
As far as oversteer/understeer, I don’t think weight distribution plays that big of a role. In fact, with less weight on the rear, it’s actually easier to get a car to oversteer because there’s less traction back there.
Also, while we’re talking about understeer, ALL modern cars (FWD, RWD, AWD, 4x4) are setup to understeer from the factory, because the car’s safety systems are designed to work when hitting an obstacle head-on. If you’re going to lose control and slide off the road, it’s better to hit the tree head-first than sideways.
This is generally true but it’s a function of engine placement first, and drive wheels kinda follows from that. That is to say, transverse engines (typical of FWD and FWD-based AWD cars) take up a lot of room sideways in the engine bay, which leaves little room for a proper suspension. Mac struts are both cheaper and better packaged. Longitudinal engines (typical of RWD, but there are some FWD and AWD exceptions like Subaru, some old Acuras, and some old VWs) will have more room in the engine bay for a double wishbone.
That said, 88-00 Civics all had proper double wishbones while being FWD, a setup that you can still find from Honda on the Acura TSX. Meanwhile, the “Ultimate Driving Machine” has always had a MacPherson strut setup and that doesn’t stop people from describing M3 handling in angelic terms.
No doubt. There’s plenty of great handling FWD cars, and there’s plenty of shitty handling RWD cars. In my experience, the emphasis that car enthusiasts place on RWD is totally out of proportion to the overall benefits. Mostly, that comes down to marketing and peer pressure.
In terms of racing, RWD has a distinct advantage (aside from the weight distribution, which can generally be fixed), and that is that they can put the power down on corner exit slightly sooner. That advantage doesn’t amount to a whole lot, though, and FWD and RWD cars are typically classed differently anyway. In classes where they’re the combined, like SCCA IT (FWD Acura Integras compete against RWD Miatas), the difference isn’t really a difference.
The only areas where FWD is completely insufficient is burnouts and drifting, so there’s that.
I believe torque steer can be mitigated with a longitudinally mounted engine (my '84 Audi 5000 had this, and apparently the A6 and A8 still do. Wonder why other manufacturers don’t use this model) which eliminates the need for unequal-length half shafts.
Longitudinal engines in a FWD car are less ideal from a packaging and weight distribution perspective because the engine hangs even further ahead of the front axle line than in a transverse setup. RWD setups don’t have this problem because they can put the engine behind the front axle line.
That said, not all FWD cars have unequal length half shafts. My Integra, for example, has equal length shafts thanks to an intermediate shaft that’s bolted to the back of the engine, effectively extending the reach of the differential. This is one of the tools that I alluded to in my above post.
That said, it helps a lot, but it doesn’t completely eliminate it. And it’s an extra part with some big bearings that the engine block has to be designed to support, so automakers are reluctant to use them from a cost perspective.
In practice, though, FWD cars are typically lighter and cheaper (owing to the economies of scale of their pedestrian econo-car roots), and for a given budget it’s very often possible to find a specific FWD car that will be faster than its specific RWD competition at the same price point. And that’s why I think enthusiasts are wrong to discount FWD cars as a matter of course.
I’m fond of pointing out that front-engine cars confer absolutely no handling advantage over mid-engine cars, which is why every proper ground-up race car design starts with a mid-engine layout. And yet, you don’t ever hear enthusiasts say things like “No front-engine car can ever be a true sports car,” which is exactly what I heard someone proclaim about FWD cars last month.
I have a 2002 VW GTI with the 1.8T engine which makes 180 peak HP. Would I notice torque steer in my car? I don’t know that I ever have. Isn’t this something you would only notice under hard acceleration in a sharp curve? And isn’t that something you would only encounter at a track? I mean, I never accelerate hard into a sharp curve in daily driving.
Why is that? Is it just because all that mass over the front wheels provides additional momentum that is trying to go straight while you’re trying to turn?
What does that mean?
I have to admit, one of the reasons I created the OP is that I’ve been reading a lot of car reviews in preparation for buying a new car, and I’m strongly considering a certified pre-owned BMW 3 series. I do enjoy driving, and I’ve been behind the wheel of a Bimmer a few times before, and while I could certainly enjoy the handling, I don’t know if I could put my finger on exactly why–whether it had anything to do with rear-wheel drive. And I’m not sure I can rely on the car magazines’ opinion of whether or not that’s the case, because as I’m sure everyone posting in this thread knows, they tend to laud BMW to such an irrational degree that one wonders whether their judgments are objective.
no mainstream automotive publication is objective. they can’t be, 'cos if they were they’d lose access to media events and press junkets. there are some who like to pretend they’re immune to that (e.g. “the truth about cars”) but they’re just spewing bullshit.
I thought FWD had better traction because of the greater weight on the drive wheels. Isn’t that part of the reason why some FF cars were successful in rallies (e.g. Mini)?
I would tend to disagree. I worked for them under Csaba Csere (although just as a freelancer), and I never got the sense they were particularly partisan in any direction. Maybe things have changed, I don’t know, but Csaba was an ethical journalist and engineer.
Yes. Go to an empty parking lot or some place with some room and stop with your wheels pointed straight. Take your hands off the wheel and accelerate rapidly. You will not go straight; you steering wheel will turn a bit on its own.
A big issue with FWD vs RWD is traction. Getting around a racetrack fast is about maximizing that traction, especially through corners. There’s only so much traction available from a tire and it can be used for turning, braking, and accelerating. FWD puts the majority of all of these on the front tires. The extra weight (engine and transmission) over the front tires exaggerates this problem.
