Tuesday, February 25, 2020

"It's 4 wheel drive, not 4 wheel stop."

That's an axiom here in the land of the ice and snow, and we had a nasty little storm Sunday night into Monday morning that drove that point home. The storm didn't put down much snow, but it rained first, then got really cold, and then we got a dusting of snow, which resulted in very slick conditions on the roads. It took me 45 minutes to go less than 5 miles on the freeway to the exit where they kicked us off onto surface streets. In that 5 mile stretch of freeway, there were 20 accidents before 6 am, and they kept coming until mid-morning. A disproportionate number of those wrecks involved 4 wheel drive trucks and SUVs.

4 wheel drive is a wonderful asset to have. I've driven exclusively 4x4 vehicles daily for over 15 years, and I will never be without one again. Sadly, their capability can convey a false sense of security to their owners who feel like their large, stable vehicles can go anywhere and do anything. Sadly, this causes them to encounter risks they don't even know they're taking, so I'd like to review what 4 wheel drive can and cannot do.

What 4x4 Can Do
Four wheel drive increases driving traction by delivering power to all four corners of the vehicle. This keeps slipping wheels from spinning in rough or loose terrain. They can also help in rough terrain by invoking gear reduction, increasing torque at the cost of speed. This same gear reduction aids in slowing the vehicle without using the brakes.

What 4x4 Cannot Do, 
or How It Doesn't Help
Four wheel drive does nothing to increase friction between your tires and the surface you're driving on. No matter the gearing or how built your rig is, without friction you won't be stopping. This is the thing that many people forget: they buy big fancy 4x4 rigs and get a false sense of security right up until they hit the car in front of them or a road barrier.

The other issue of concern with a four wheel drive is that with the system engaged, your steering ability greatly diminishes. When your steering wheels are also providing power, turning will be rougher riding and more difficult, especially at low speeds.

Knowing what your vehicle is and isn't capable of will save you a world of hurt.


1 comment:

  1. and under acceleration if the front tires spin and lose their traction steering input is totally lost to the front wheels


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