Front-wheel drive (FWD) cars make up a huge percentage of the vehicle market today. FWD was originally introduced to the American in a mass marketing push in the '70s, and was touted as being safer than rear-wheel drive because the engine’s weight was over the front tires and gave you better traction — true statement. But what American manufacturers weren’t sharing was that by including the entire drivetrain in one small package, it installed in one movement and made the vehicle cheaper to manufacturer.
So, where does the “safer” part come in? Because the front tires now had more traction as a function of more weight on the them, the car will “pull through” wet or snowy road surfaces better. Of course dirt roads, which rally racers in Europe run on a lot, love front-wheel drive. When FWD first came to America, it was in mostly underpowered cars and the nasty habit of “torque steer" (the vehicle wanting to pull to one side on acceleration) didn’t become apparent until the horsepower numbers went up. This was caused because the axle lengths from the transaxle to the front wheel hubs twisted at different rates and one wheel would pull the vehicle (usually right) to one side.
Today’s FWD systems have all but cured that and work so well most drivers can’t tell whether the vehicle is FWD or RWD...but back to the biggest safety gain. All but the best drivers will, when encountering a vehicle’s desire to go straight (understeer) despite the driver having put steering into the front tires will automatically jump off the throttle, which, with FWD, is exactly the right thing to do. RWD doesn’t usually react well to such a scenario as that same move will slow the rear tires in relation to the fronts and cause the vehicle to go into an over reaction (oversteer) to the steering input.
Kommentarer