Front wheel or rear wheel

Factual Questions
1

On cars, that is. Most modern passenger cars in the US are front wheel drive. This, it seems to me, decreases weight (with no long drive shaft) and frees up interior cabin space for passengers and cargo. It also makes low, flat floors, such as mini-vans possible. Is there a trade-off in efficeincy, safety, or control.

Most racing cars seem to be rear-wheel drive. If anyone would know a lot about safety, efficiency, and control, it would have to be race card drivers. What do they know, that Detroit (and Tokyo) don’t share with us lay-drivers. In addition, I read that the nation’s police departments are having trouble finding vehicles because the only large, rear-wheel sedan made in the US is the pricey Ford Crown-Victoria. They want a rear-wheel because they say they’re more durable.

Okay, enough rambling. So which is better, rear-wheel or front-wheel?

2

There isn’t a linear answer to the “better” question. Safe, functional cars with good performance can be designed either way. Then cars as pushed to extremes such as racing or trying to make the cut on Fox’s World’s Most Irresponsible Police Chases Caught On Video things are different. Extreme acceleration tranfers the force of the weight to the rear wheels, this helps a rear wheel drive car but can make a front wheel drive car lose traction. Front wheel drive cars can be at a disadvantage under cornering because the front wheels are taking all the side loads of steering as well as all the power load.

3

The weight reduction caused by elimnating a drive shaft is negligible. Drive shafts are hollow and weigh less than 15 pounds.

4

>> Front wheel drive cars can be at a disadvantage under cornering because the front wheels are taking all the side loads of steering as well as all the power load.

Padeye, I disagree here. One of the strong points of front wheel drive is precisely this: They will corner better because the front wheels are pulling the car around while in a rear wheel drive the wheels are pushing the car outwards and therefore it is more likely to fishtail. This is one of the main selling points of front wheel drive.

The best (of course) is all wheel drive but this is substantially more expensive. Front wheel drive works well for small passenger cars. I had to get a rear wheel drive car becaus I often pull a trailer and, with the weight of the trailer, the front wheels sometimes do not have enough traction.

I often watch a boat launching ramp and many front drive cars start skidding on the wet ramp and cannot pull the boat out while my car, even though it is smaller and less powerful can handle it quite well.

In steep ramps rear wheel drive works better because most of the weight goes to the rear wheels. I remember many years ago, in a small front wheel drive car, we were trying to go up an unpaved road covered with thick snow and the card just could not go up the inclines. After a while of fruitless trying, I told the driver I could take the car up all the way to the cabin easily if he would let me drive. Everybody got in the car and I turned the car around and drove backwards all the way (a couple of miles) and we made it without problem (not counting my stiff neck by the time we arrived)
I had converted the front drive to rear drive by turning the car around. :slight_smile:

So the answer to the question is : it depends.

5

Drum God (btw- if you’re the Drum God then I get to be Drum Jesus) I must recommend that if you have $40 and a PlayStation, you go purchase Gran Turismo or (better yet) Gran Turismo 2. For the longest time I couldn’t visualize the plus and minus of front wheel -vs- rear wheel -vs- all wheel, but that game sets you straight in a hurry.

6

DG, you pretty much nailed it in your OP.

FWD is lighter (no rear axle, 150-400 lb), and the interior space thing is a plus for selling cars. The one thing you overlooked though, is FWD is much cheaper for the manufacturers to produce (fewer parts, cheaper platforms, and quicker, less complex assembly). That’s the main reason it’s becoming so universal. It also provides better traction in some situations (mainly due to the weight being concentrated over the drive wheels).

As for RWD being more durable, it is, but that is only because the FWD systems were designed to be as light as possible, while RWD systems were designed for insane torque levels. It’s just coincidence it wasn’t the other way around.

IMO, RWD is better for any vehicle that does anything beyond basic, normal transportation. The whole body has to be more rigid, engine braking is safer, acceleration is better, and towing puts weight on the drive wheels (rather than levering them off the ground).

Also, when something goes south, it is nearly always much easier to get to and repair with RWD.

7

First point, “most passanger cars” don’t use front wheel drive. Virtually all mid-range 4 door sedans use front wheel drive, as well as several smaller economy vehicles. Virtually all luxury and performace sedans use rear-wheel drive, with the exception of Cadillacs. Cadillac has been getting hurt recently, and one factor is believed to be the front-wheel drive, becasue most enthusiasts who would spend big bills on a car want the best performance, and front wheel drive doesn’t afford that.

Front-wheel drive is mainly a cheap method of offering better slick condition handling. Initially, there is a inordinate amount of weight on the front wheels, offering better traction on the front-drive wheels under slow conditions. Also having the drive wheels ahead of the center of gravity greatly reduces the likelyhood of a spin, and marrying the steering to the drivetrain has the advantage of keeping the force applied parallel to the desired direction of travel.

All this said, there are alot of drawbacks to front-wheel drive. Most importantly it is more expensive, and generally less reliable and more expensive to service. The real factors that one notices is the loss of performance. One of the most critical factors for excellent handling and performance is a 50/50 weight distribution. Front-wheel drive cars are very front heavy, a major drawback in cornering, accelerating and decelerating.

This is why front-wheel and rear-wheel drive cars have become specialized. You’ll see front-drive cars in the grocery-getters and the vehicles where saftey is at an absolute maximum. E.g. family sedans, and minivans. You’ll see rear-wheel cars in all performance, and utility vehilces.

A new revolution to this might make front wheel drive cars obsolete. The luxo-sport sedans that were always balancing high performance (rear drive) with saftey, developed the new active traction control (or whatever het companies brand name is) where a computer duduces any slip or spin of the wheels and applies the brakes of the 4 wheels independantly to regain control, effectively cancelling the benefit of front wheel drive. If these systems become totally relaible and effective maybe all cars will be rea-wheel drive again. But, I can think of lots of cars that I’d love to have in All-wheel drive.

8

Warning: This is a religious issue for some car people.

When a car is turning, none of the wheels on the car point exactly in the direction of the car’s true line of travel. Every wheel has to slip slightly for the car to get around the corner. When accelerating through a turn, the driving wheels tend to slip more than the other wheels. That’s why front-wheel drive and rear-wheel drive cars handle differently; the wheels that slip the most are on different ends of the car, and have different duties (steering or non-steering wheels). The two behaviors that are generally discussed are “oversteer” and “understeer.”

“Understeering” is the tendency to plow straight ahead in hard cornering, or at least, to turn less sharply than the steering wheel’s angle might lead one to expect. This happens when the front wheels are slipping more than the back wheels, and it’s the natural tendency of front-wheel drive cars. It’s considered safe, because most people understand what to do (slow down and/or turn the wheel harder) to correct for it, even if they don’t have to think about it.

“Oversteering” is the opposite; it’s the tendency to turn more sharply than one might expect from looking at the angle of the steering wheel. This is what rear-wheel drive cars tend to do when accelerating through a turn, although the tuning of the suspension, the tires on the car, the weight and power of the car, among other things, can make this tendency more or less obvious. Oversteering is really frightening and very dangerous if you’re not prepared and practiced at it, and it can lead to a spin-out. However, as you can see in countless car-chase movies or in dirt-track racing, it can get the car around a corner very, very fast, if you really know what you’re doing. Driving this way is sometimes referred to as “steering with the throttle,” since careful modulation of the gas (and thus the amount of slip at the rear wheels) is a must to make this work. Most folks who have experienced oversteer have probably done it when driving a rear-wheel drive car on ice. Use a little too much gas through a left-hand turn, and the back end of the car goes sailing out to the right. This is where the old-fashioned advice to “turn in the direction of the skid” comes from. By spinning the steering wheel to the right, at least some of the wheels on the car (the front ones) will be facing in the direction the car is actually moving (forward and right) and thus will be rolling instead of sliding. This greatly increases your chances of recovering, since you’ll have at least a little bit of steering and braking control from the front wheels while you wait for the back end to settle down again. More often than not, though, the driver is confused by the strange motion of the car and does the wrong thing. And unfortunate number of Porsche 911s have met an untimely end at the hands of wealthy but inexperienced owners who didn’t know what oversteer was, let alone know about the car’s tendency to do it.

In short, rear-wheel drive really does provide advantages for racing, for stunts, or for emergency pursuit driving - and only experts need apply. If you’re out enjoying the thrill of oversteer in your rear-wheel drive car, you’d better be on a racetrack, or you might soon be in jail - and you’d belong there, too. For driving to work or to the store front wheel drive is just the thing.

9

You guys can argue front- or rear- wheel drive for forever. All I know is that I have had a rear-wheel drive for the past 2 Minnesota winters and would give ANYTHING to be able to afford a front-wheel drive car. Just a tiny bit of ice/snow at intersections makes cornering and stopping a hit-or-miss proposition.

10

You are absolutely correct when driving under normal street conditions. Things get very different when pushing a car to limits of traction. Controlled oversteer can actually be quite desirable.

It can be difficult to get a front wheel drive far to show trailing throttle oversteer but with proper suspension modifications it can be done and it makes for much faster cornering.

Pushing most FWD cars to cornering limits causes the outside front tire to tuck under and actually ride on the ouside sidewall. It doesn’t do a good job of “pulling” through a corner.

When I ran a VW rabbit in solo slaloms I added lower, stiffer spring, hard bushings, Bilstein DeCarbon type style shocks and anti sway bars. With a RWD car the front bar would typically be stiffer but with the rabbit I found it best to use a 28mm bar in the back and a 22mm bar in front. The extra rear roll stiffness actually allowed the inside rear tire to lift off the ground under extreme cornering while both front tires stayed firmly in contact with the pavement. The best technique for this setup was to enter corners a little and let off the throttle very slightly at the apex. This transferred a little weight to the front and allowed the rear to come around, not “fishtailing,” putting the car in a good position to accelerate to the next corner.

This isn’t how any sane person should drive on the street but when you get it right on the track it’s cooler than all get out. When you get it wrong you knock over a bunch of cones and end up pointed in the direction you came from. In all the slaloms I did I never hit a cone.

Lagged has it right and explains it better than I think I did. He speaks the SD about Porsche 911s too. I once scared the bejesus out of a guy who let me try his 911SC on a back road of a navy base. I knew what would happen when I let my foot off the throttle in a corner but apparently had never pushed the car very hard and didn’t.

11
      • Good road-racing drivers never go around a corner with all four wheels touching the ground; all four tires only touch once during the middle of the turn. Entering the turn, you are supposed to be braking hard enough to lift the rear inside tire, and halfway through the turn, you are supposed to switch to accellerating hard enough to lift the front inside tire as you exit the turn (important note: very few regular cars have suspensions firm and solid enough to try this safely). This is the reason that front-wheel cars suck at roadracing: both cars can stop just as well as each other but front-wheel-drive cars can’t accellerate out of corners as well as rear-wheel-drive cars can. - MC
12

Yes, this is something of a religous issue with no clear-cut answer as to which is “better”. This is why both systems have been around for a long time - Cord, for one, was front drive in the 30’s. Although, for American makers, FWD went completely out of style for a couple decades until the Toronado in the 60’s. Some European makers still used it.

One thing nobody has mentioned is the added design complications of having to drive the wheels that do the steering. Makes for very complicated front ends and very simple back ends. The first car I bought new was an '80 Honda Accord - I remember looking underneath the rear and finding it amusing that the rear wheels looked like they were just bolted onto the chassis - I can’t remember how the suspension was arranged in the rear, but it was very simple.

Traction - yes, FWD loses going uphill, though it’s generally more surefooted in other situations. Partially a matter of
weight distribution. FWD cars are very
nose heavy, with the weight right over the driving wheels. To get this advantage with a rear drive car, you can go to a rear engine. Before I had the Accord, I had a VW Beetle. Old style Beetles were poor man’s Jeeps - they would just about climb a tree if you wanted them to.

Rear engines seem to have gone by the wayside for now - possibly because it’s a good way to make the oversteer that people have mentioned truly vicious, and too many people would kill themselves. That Beetle I mentioned couldn’t be driven hard into a curve anyway, but need I mention the Porsche Carerra?

Personally, I’ve now driven front drives like Saabs for so long that I probably unconciously think cars are SUPPOSED to yank you around by the nose and understeer.

On the current crop of new cars, I don’t think you can associate front drive / rear drive clearly with any particular type. If you go to http://www.carprice.com you can select on this basis. FWD runs the gamut, even including some performance oriented cars like the Mitsubishi 3000GT. Neons and Daewoos are front drive, but so are most Cadillac models and the Lincoln Continental these days. Rear drive is a bit more specialized, weighted towards performance vehicles, trucks and 2WD versions of SUV’s (a silly concept to begin with, and the 2WD version of a RAV4 is FWD). Still, the BMW and Mercedes passenger cars are rear drive,
as is the Infiniti Q45 and the Lincoln Town Car.

One reason I’m up on this is that I’m in the market for a new car. I’m actually interested in the full time 4WD systems that are out there these days. Subaru and Audi have been doing this for years, and it has some appeal. Any opinions on Audi’s anybody? Yes, I know an A4 is just a VW Passat with pretensions, but I kind of like them …

13

Rear wheel drive would seem to suit the more experienced drivers.It does not seem to be something that improves performance and handling by itself, you have to know how to make use of it.All the cars my father drove in the 1960s-1970s were two seater rear wheel drive sports cars and to drive them you seemed to have learn off a lot of techniques like heel-toeing and prodigious use of the handbrake.
I have never personally driven cars powerful enough to mess up the handling so I guess what I know is mostly anecdotal

14

Selectrac. ('80s AMC Eagle and fullsize Jeep full-time 4wd system)

15

On dry pavement I would much, much rather have a rear-wheel drive car. The thing is, they typically start with a bit of understeer, but application of the throttle can modulate the turning characteristic towards oversteer. By getting the throttle set correctly in the turn, you can balance the steering perfectly. Not so in FWD cars.

On ice and snow, I’d rather have FWD. You just get much more traction and controllable skids with FWD.

16

In ice and snow, rear wheel drive is strictly for the brave, or the foolish. I see no need whatsoever to attempt to tool about town with my wheels spinning, and the rear end sliding out from under me.

Me, I’ll gladly throw the lever, and lock in 4x4. It’s not as efficient, but I ain’t the one sliding into fire hydrants.

17

In the sixties (sorry another story from my dad) cars like the Hillman Imp with rear wheel drive were actually better in the snow because the engine was in the rear and gave the rear wheels superior traction which also made them popular for rallying. Modern cars like TVRs may seem like rear wheel drive and front engined but their engines are so far behind the front wheels that they can be considered mid engined. It is kinda negated by the massive power supplied by their engines though. Iguess the point is that its all relative.

18

There is one place where FWD really helps when launching a boat. If the ramp has moss or algae below the water line a RWD driver can get really surprised if the rear wheels get dipped and lose traction. I have seen this myself a few times, and I am sure it has ended up on America’s Funniest Videos, too.

My dad, who built his own trailer, installed a telescoping tongue so that you could push the boat back from the truck about 6 feet to keep the wheels dry.

19

Think of it from the perspective of a nervous father, shopping with his son for his first car. He’s got a choice between a 1990 Chevy Sprint Turbo or a 1976 Monte Carlo with a small block. They cost the same.

You’re thinking about that decreasing radius turn on the way to your house.

You see him coming home one Saturday night, three beers left from a twelve of the Beast rattling in the back seat, doing about seventy. The Boy remembers the turn too late, and downshifts going into it.

The Sprint is going to draw a nice, straight line through that turn like a tangent on a geometry test. Fortunately, there’s some big four-foot wide oak trees to slow him down at the end.

The Monte would draw a big, pretty figure eight into those same trees.

Would, that is, except The Boy is busy in the back seat of the Monte, which is large enough for your son to engage in healthy premarital sex. Then he has to drop the girl off, carefully. See? The rear wheel drive car just saved your hypothetical son’s hypothetical life.

Nobody gets laid in front-wheel drive cars.