By Allen Penticoff
In the previous Mr. Green Car (Feb. 6-12 issue), I wrote that I have personal experience with all the major vehicle drivetrain systems. Again, I define a drivetrain as the equipment used to convert the engine’s output to making you go. In the previous column, I wrote about the traditional use of rear-wheel drive. In this column, I’ll discuss front-wheel drive (FWD).
Front-wheel drive in the U.S. goes back to the 1929 Cord L-29. The more famous Cord 810 luxurious big car of the late 1930s is still stylish by even modern standards and made a lot of people think. But its FWD technology did not catch on in this country.
Although the first European FWD appeared about the same time as the Cord, it was after World War II that a great number of FWD automotive designs were developed and marketed. Smaller, fuel-efficient cars were needed in an economic area in recovery with high fuel prices.
Fuel prices never really dropped in Europe afterwards, so smaller vehicles remained the most common personal transportation (besides feet, bicycles, motorcycles and public transportation).
Front-wheel drive did not make any significant appearance on the American automotive landscape until the arrival of the Oldsmobile Toronado in 1966. In 1967, the sibling Cadillac El Dorado also appeared on the market.
I still recall the promotions of these attractive cars extolling the virtues of the absence of the transmission “hump” in the front seat footwell. Both had long, profitable runs.
However, FWD did not really take off in the U.S. until the 1980s. Previously, a few Japanese, French, Swedish and Italian imports had brought FWD to America at the outbreak of the 1970s oil embargoes. My own introduction to FWD came in trading in an essentially new Ford Econoline van on a new red 1975 Fiat 128SL. Thus began my long affair with smaller cars. But it was the introduction of the “mini-van” by Chrysler in 1984 that really put front-wheel drive on the American map. Personally, a long string of Honda Civics began with a used 1973 hatchback I came home from the Army with in 1979.
Now, front-wheel drive is ubiquitous. They are everywhere. Nearly all mid-size and smaller cars now use FWD, and the reasons are that it works well for most purposes. FWD provides more cabin space (flat floors), generally better traction, and reduced weight and manufacturing cost.
Gone is the long steel drive shaft and heavy rear differential of the rear-wheel-drive drivetrain. With a FWD drivetrain, the differential (explained in part one of this series) is incorporated into the transmission case. There are two axles to the front wheels with constant velocity (CV) joints that allow the front wheels to steer and provide drive force at the same time. The rear axle can now be much lighter or independent suspension done economically.
Front-wheel drive provides excellent traction — with a catch or two. As weight shifts rearward during acceleration, the front wheels feel reduced traction. FWD can easily spin in snow, ice or rain when starting out from a dead stop. But once the weight re-balances, then the weight of the engine over the front driving wheels provides excellent traction. FWD also “pulls” the car rather than pushing it, so it is more stable in snowy conditions.
A trick to FWD when it feels skittish is to press lightly on the accelerator. This provides pull that straightens things out. However, if you apply too much power while turning, FWD will lose traction and, therefore, turning ability; the car will understeer, and you’ll not turn as sharply as needed — or, indeed, at all. Modern FWD systems have all but eliminated handling issues related to FWD — very sporty cars feature it now.
Some modern FWD systems (particularly mini-vans) incorporate “traction control.” What happens is that the same speed sensors that monitor and provide for anti-lock braking systems watch for one wheel to be spinning more than the other when power is applied. The traction control system, if engaged, will then apply a little bit of braking action to the spinning wheel and allow the other wheel with better traction to do the pulling. This system works great and is nearly as good as all-wheel drive (AWD) in getting through snowy conditions. In fact, it may be better overall when economics are factored in (I’ll explain that in the AWD column).
If you are considering buying a FWD vehicle that offers traction control as an option, I highly recommend you take it, although it is quite often packaged in upgraded versions where you pay for many other things you may not really want or need. In a used vehicle, the price difference will be far less significant.
As far as efficiency is concerned, FWD is found on the most efficient vehicles you can buy. Nearly all hybrids are FWD, and even non-hybrid FWD can obtain very high fuel economy. My own 1992 Honda Civic VX EPA rated at 55 mpg as a non-hybrid. This is, in part, because of the lower weight of this style of drivetrain.
There is no free lunch, and for all the great things about FWD, the small downside is that the CV joints wear out. Worn (usually the rubber boot breaks and they lose clean lubrication) CV joints make a clicking noise when you turn. They will last more than 100,000 miles, but they can be replaced for a fairly low parts cost, and are not terribly labor intensive to replace. An advanced do-it-yourself person can replace them in a driveway in a couple of hours. I’ve done plenty. I think that the great savings in fuel, and benefits of FWD, far outweigh this one downside.
Another minor issue is that one should pay more attention to rotating the tires regularly. The front tires are doing all the work. If you never rotate them, the front tires will be worn out, while the rear tires will look like new.
Overall, I give front-wheel drive the highest rating of all the drivetrain systems for general usage. It does everything quite well. I don’t care for it if towing a heavy load, but FWD can tow lighter loads just fine. I recently sold an AWD because I got tired of its related expenses. I’ve done well with small FWD for decades, and decided we would go back to it.
The next Mr. Green Car will explore the four-wheel drive (4×4) drivetrain. Stay tuned.
From the Feb. 20-26, 2013, issue