does driving at a constant speed (pressing the accelerator constantly but with varying amounts) give better gas mileage or does getting to a certain speed and coasting for a while before pressing the accelerator do better? Why?

Question

I feel like the first one should do better, but I don’t get why, and while I’m driving I keep thinking the second version will somehow end up better – but how do hills affect this?

In: 3

Answer 1

Ok to be fair I feel like it’s a bit more complicated that everyone is making it seem.

If you’re driving on a level highway consistency is best and lower speed is better in your highest gear.

If you’re driving through mountains you’ll almost always burn more fuel regardless but in those instances it’s more efficient to accelerate down the hills because it takes less energy and use that speed to help you get up the next hill while letting your vehicle bleed off speed on the ascent. If you stay in constant speed in the hills you’ll be struggling and wasting fuel on the climb and you’ll not be taking advantage of the assist gravity gives you on the way down