Car talk

by barbaragarn

Several folks had to cancel out of sessions lately due to bad weather (a pity the rinks NEVER close).

But as I was sliding around in the yuck, I wondered if it’s better to drive in lower gear with more power to each wheel (though faster spinning speed) or higher gear with less traction but spinning slower. I asked car genius and hockey player Seth Miller. I thought everyone would find his comments useful for driving on slick roads (and also just the curiosity factor). Here’s his reply:

All engines have a “power curve.” Do a Google image search of it.

You’d want to avoid driving with the engine running in the rpm range that makes the most power as a small change in gas pedal position would cause a greater increase in power sent to the wheels possibly causing wheel spin.

If you were to shift to a higher gear so that the engine rpm were off of the peak, a small change in gas pedal position won’t change the power output much and as such be less likely to cause wheel spin.

As an example, think of driving at a steady 30 to 35 mph in 3rd gear (in dry conditions). If you then floor the gas pedal, you’ll most likely start to accelerate pretty quickly no? Now, drive at that same steady speed in 4th gear. If you floor the gas pedal, you most likely will accelerate, but not at anywhere near the rate you did in 3rd.

In 4th gear, the engine isn’t at the peak of the power curve and so it struggles to accelerate the car. In 3rd gear, the engine is somewhere near the peak of the power curve and acceleration is easy.

Now, in wet or snowy conditions, the same holds true, except instead of accelerating in 3rd, you’ll spin the tires. In 4th, you might not. So, it would be better to drive that speed in 4th so long as you can maintain that speed (don’t need the power to go up a hill, etc.).