Four-wheel drive is awesome. But, if you’re a new driver or simply new to four-wheel drive, the power can be deceiving. While you may feel invincible being able to truck through snow and ice with ease, it’s important to realize that even four-wheel drive has its limits.
Knowing the Dangers
One of the most common misconceptions is that four-wheel drive includes handling on slick, ice or snow-covered roads. It doesn’t. 4WD doesn’t make it easier to stop or give you more stability in turns while braking. You’ll still have to slow down and brake sooner when you’re turning. Plus, if you drive faster than conditions allow, you’re far more likely to flip and roll, as four-wheel drive vehicles tend to have a higher center of gravity.
Another common misconception is that 4WD vehicles provide more traction. They don’t. Only tires can provide traction and, even then, only a tiny footprint actually touches the ground so cautious driving and early braking are key.
Know how to engage
Today, most 4WD systems can be shifted into or out of 4WD with the push of a button. The most sophisticated 4WD systems are fully automatic and will shift into and out of 4WD as the system detects the need for more traction.
Older or more basic 4WD systems have to be engaged manually with the vehicle, typically at a complete stop with the transmission in Park or Neutral. Never try to engage these systems when the vehicle is moving- this can cause some serious damage and require expensive repairs. For example, an older, part-time 4WD system on dry pavement can break the front axles, shear the differential gears and even break apart the differential case. As soon as you hit dry pavement, shift back into 2WD.
Know when to engage
Knowing when to engage 4HI vs 4LO seems to cause the most confusion for 4WD vehicle owners, so here are some rules:
Use 4LO when…
- you need more torque (power) for heavy pulling at slow speeds.
- you’re climbing steep grades at slow speeds and need extra power.
- you’re descending a steep hill with a heavy load. The low gearing provides engine braking assistance.
Don’t use 4LO to get unstuck in mud and snow. The extra torque will cause the tires to spin.
Use 4HI when…
- you’re on slippery surfaces, driving at street or highway speeds (30-65 mph)
- you’re stuck in snow, mud or ice.
It’s important to remember that, when you’re in 4WD, you’re spinning a lot more heavy metal. Getting the extra gears and drive shafts up to speed and keeping them spinning takes a lot extra energy, which lowers your gas mileage. Whenever you can, turn it off and save a few bucks at the gas pump.
If you get stuck
Even with four-wheel drive, there’s always the possibility of getting stuck. If that happens, resist the temptation to rock yourself out by shifting between drive and reverse. Instead, shift into 4HI and slowly feather the gas pedal to inch your way out. Don’t spin your wheels. If that doesn’t work, rock the vehicle back and forth by applying and releasing the gas.
A note about all wheel drive
All-wheel drive is similar to the 4WD, but they’re not the same thing. AWD also sends torque to all four wheels constantly, but drivers can’t control the level of power and don’t have the option to operate in two-wheel drive. For more on the difference between four-wheel drive and all-wheel drive, and when each is best check out last week’s article.
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Since 1988, our family owned and operated service center has been providing top quality auto repair services to Agawam, Feeding Hills, Southwick, West Springfield and the surrounding Massachusetts communities. If your car needs maintenance or repair before this winter season, call us at (413)314-2280 or schedule an appointment online.