Accelerating before going up a hill?

[wildbears]

Accelerating before going up a hill.

Does this save energy or waste it?

And what about the situation where you have a downhill stretch before going up the hill?

It seems semi's do this but is that only to preserve speed?

[jpel]

If you are talking strictly about fuel economy, the answer is accelerating up,a hill wastes fuel.

[wildbears]

Fuel economy and, for the cyclists, energy economy. Thanks.

[955i]

I don't know about trucks or motorcycles, but for sure when I'm on the Merckx, if there is a downhill before an uphill, I ALWAYS put it the big chain ring and get some extra speed up and carry it as far into the hill as possible. I do this with as little expenditure of energy as possible because I am going to need all I have to climb the last 2/3's of the hill.

[wildbears]

Good point. I guess the question then becomes how much effort to put into the uphill section when on a bicycle.

[cabnfvr]

With 175 hp it just doesn't seem necessary. We saw a sticker on a twin turbo 350Z a few years ago that said, "You save, we use."

[justjoe]

When it doubt, gas it out