Wednesday, January 14, 2009

Rear Wheel Drive vs. Front Wheel Drive


Now that consumers in North America have come to the conclusion that they can't afford trucks and SUV's I'm guessing that more people than ever will be buying and driving front wheel drive cars. This is going to be quite an adjustment for them, and may also be dangerous.

I have been driving front wheel drive since 1984. I drive a lot in winter and I don't like getting stuck, so the front wheel drive suits me. Over the years I have gotten used to the differences between rear and front wheel drive. I'm comfortable with front wheel drive, I have rarely gotten stuck, and I've saved a lot of money on gas and on the purchase price of the cars also.

A front wheel drive car allows more interior space and less weight for the same outside dimensions. Without the bulky and heavy drive shaft and differential in the rear, all the back end of the car can be built lighter and have more room inside. And yes it's cheaper to build, so that may explain the lower average prices.

Is it safe to drive? Front wheel drive is still relatively new, and if you don't learn new habits, you may be in for a hard time with it. Number one would be the old idea of buying snow tires only for the rear of the car. With a front wheel drive vehicle, you must buy winter tires for all four wheels. That is because if you put the winter tires only on the front and not the back, the rear will spin the car around and you will lose control.

That brings us to the the most dangerous characteristic of the front wheel drive cars. If you are in a low gear with the engine revved up rounding a corner, and you suddenly back off the throttle, you may provoke a rear wheel slide that will spin the car around. This situation does not come up a lot, and probably never in the lifetime of careful drivers. But aggressive drivers need to learn the behaviour of a front wheel drive car if they are going to drive one. In my mind, this is a fair requirement, but I also know it's not going to happen one hundred percent. Aggressive driver does not mean good driver, sad to say. And what is the best way to regain control? Well, put the car in neutral, or push in the clutch, which makes it work like a rear wheel drive car. (Although a very nose-heavy one) Another way is to push the accelerator, which may not come naturally to many old style drivers. Anyway, many new stability control electronic devices are starting to become available, which can eliminate most of this problem.

A front wheel drive has more weight over the driving wheels, which gives more traction to get moving or keep moving in slippery situations. Not only do you have the extra weight, but you can point the driving wheels where you want to go when stuck. With rear wheel drive, the only way to get unstuck is to have the front wheels pointing straight ahead, in line with the rear wheels. To reinforce the difference between rwd and fwd, watch traffic stopped on an uphill section waiting for a traffic light in a snowstorm. When the light turns green, and rear wheel drive cars sit and spin their tires through the entire green light. Sometimes they slide sideways to the curb with no forward progress. Front wheel drive cars with the same type of tires in this situation will be able to make it through the light (unless they are stuck behind the rear wheel drive car!)

1 comment:

  1. I've been driving front-wheel drive cars since 1968, when I worked as a driver in the UK, and owned my first FWD before Detroit switched ...
    http://www.tgw.on.ca/Matti/automemo/det0090.html

    The Mini was great in the snow - except when it got high-centred ;-)

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