February 25-March 2, 2008

All, Front, Rear: Which Drives Your Car? And Why Does It Matter?

In the modern era we have a wide variety of automotive companies that make a wide variety of cars. We have trucks, SUV’s, passenger cars, sports cars, exotics, the list goes on. One thing we don’t really think about is what actually drives our cars. Me as an automotive enthusiast, I will almost always pick the rear-wheel drive (RWD) or all-wheel drive (AWD) setup over the front-wheel drives (FWD). I have this crazy belief that I may someday have to get away from a bad guy and need to make a turn really quick, or this thought that if my car isn’t set up like a racing car would there is no need for it. Yes, yes I know I am quite ridiculous in those beliefs. But, there are other reasons I prefer not to drive FWD cars over the others, even though I have owned at least one of each drivetrain vehicle.

I think all of us know what each one of these stands for, but, just in case, I will go over them quickly for you. With FWD you have the engine driving the front wheels and sitting over the front wheels. With RWD you have the engine powering the rear wheels and AWD is where the engine powers all four wheels, or gives an even amount of power to the wheels at all times, or various times.

252134954_129a5a760c.jpgWith a FWD layout you have many good and bad things that can happen. First you can have a car that is roomier for what it is. Take the Acura TL. It has a FWD layout and is a very big car for its price point. It sells along side of cars like the BMW 3-Series which are RWD and is a smaller car. Because you have the driving wheels up and are less likely to have some sort of sporty differential, the car is able to have more passenger room and lots more trunk space. The biggest downfall to FWD cars though is when you start adding power you start adding too much weight up front and not enough in the rear. This adds up to more torque steer, which is when the vehicle tends to pull left or right under hard driving in a straight line or when coming from a turn and planting the gas. Another big problem for FWD cars is understeer. Every car is built to have some sort of understeer as to not make the car too difficult to deal with under sporty driving. But, a front-wheel layout has more to worry about because of the engine being over the driving wheels and causing too much weight to steer properly and smoothly under hard cornering. Still the cost benefits outweigh the disadvantages because you can achieve better gas mileage and an overall better daily driver due to the overall size being larger and the weight possibly being less than with a rear or all-wheel drive vehicle. Still, you will not see too many sports cars with a FWD layout and if they are FWD they are typically racing against other front-wheel drives or losing to rear-wheel drive cars (this is not always the case though like in Speed World Touring Car where Mazda and Audi are considerably better than BMW). FWD’s are also typically very good in poor weather such as rain and snow since there is more weight over the driving wheels.

bmw-driving-school.jpgNow with rear-wheel drive you get a car that has a brilliant balance of weight, good steering and cornering ability but at a price. You get less room due to the driving wheels being in the rear and a larger differential being in the rear. You tend to get worse gas mileage in a RWD car, or at least that’s what the critics say, but I never noticed a difference in my 330i Sport BMW in comparison to my older brothers Acura TL Type S. You tend to get more sport with a car driven by its rear wheels. The biggest disadvantage is the oversteer or fishtailing issue you get when hard on the power and driving too fast into a turn and your rear end comes out hence placing you into an oversteer or drift to some. Fishtailing typically happens when you go through a turn at a low speed and then stomp the loud pedal and your rear end starts to get a little loose looking for traction. None of these issues can be bad things, but to some drivers find that it is harder to control a rear-wheel drive car especially when in rain or snow. We call these people non enthusiasts, or just the daily driver looking for a to b transportation.

car_photo_221696_26.jpgWith all-wheel drive you get a much different sort of car. AWD is typically not referred to the same as four-wheel drive is since four-wheel drive you can turn off and make into a 2WD setup with the push of a button. AWD is different and can rarely be turned off. All-wheel drive is better on all types of road surfaces than the other two and is mainly used by sports cars like Subaru, Mitsubishi and Audi who do a lot of rally racing or by Mazda with its Mazdaspeed 6 for racing purposes. In today’s world AWD has to have some sort of rear wheel usage over the front wheels. Typically Audi with its RS4 has a 40%/60% power split between the front and rear wheels, mazdaspeed_mazda6-5.jpgwhereas Mazda uses an advanced computer system called Active Torque Split, that senses how much power needs to be sent to the rear wheels and will send up to all available power to aid in performance driving. AWD’s have a weight disadvantage to them compared with the other two drive types, because there are two axles being powered by one engine all at the same time. Also, all-wheel drive cars are typically a little worse on gas due to weight as well. But, AWD systems are so much more advanced these days that they can outperform anything else on the road due to being able to put the power of the car to the ground better with all four tires being powered at the same time. You do have a tendency to understeer in hard turns, but not nearly as much as FWD. All-wheel drive vehicles also typically run into a more expensive sports car, typically Japanese or German. But, when it comes down to it, Audi’s Quattro system has been the master of all in racing.

Why is it important to understand what is driving our cars? Well that’s simple, one day you may need to avoid a pot hole or some type of animal in the middle of the road and you are driving at 45mph, what happens then? Well, depending on the car you may be able to dodge it quickly enough or not dodge it at all. A front-wheel drive car will have a much harder time moving quickly at speed because of most of its weight distribution being up front, whereas a rear-wheel drive car will move much more easily but possibly with a little fishtailing involved, and all-wheel drive –very much so depending on the car- can provide you with a safer vehicle to move around in. Each type of car will be safe and can very well be fun to drive. I personally prefer RWD first and then AWD and hardly ever do I like FWD unless I have to take it. I personally think you should have rear, all or nothing. But, if you do that then you take away the inexpensive Japanese, Korean and American cars that are able to be made with less cost from the automaker because of how much less expensive it is to make a FWD car versus a RWD or an AWD. The decision really comes down to the consumer and what the driver needs the car for. Whether you want something like a sporty rear-wheel driven BMW, a safe and fun car like an Acura or Audi or if you want a daily all-rounder like an Audi, Subaru or Mazdaspeed 6, you will get what you pay for and what you pay for is what you want. I personally love the comfort of having the AWD system in my Speed. It gets good gas mileage while staying fun, safe and incredibly sporty for my tastes. The tail wags just fine for my inabilities. Any which way you go, you can always have fun.

Remember whatever car you buy, never let your driving habits exceed your driving abilities. Just a safe reminder from Josh at RawAutos.com.


For a better understanding of what AWD, FWD and RWD do please visit www.howstuffworks.com and www.wikipedia.org or click on the appropriate links below.

Drivelines- Front, Rear and All, The Car Guy, Wikipedia RWD, Wikipedia FWD, Wikipedia AWD


Photos courtesy of: http://www.flickr.com/photos/mrnikon//




Also check out this short video from Fifth Gear where Vicki shows you which one is better for each situation.