Uphill or downhill?

[lamontcranston]

Simple question...

Assume you've got a big hill to climb, and it's the same distance uphill as downhill ...

Is it better for fuel economy to accelerate hard to get to the top of the hill, then be able to glide for a longer time on the downhill?

or

Is it better for fuel economy to let the speed slip on the uphill and use the engine to accelerate back to speed on the downhill?

I've tried both and I can't definitively tell which works better.

[qbee42]

Neither. Let the speed slip on the uphill side, and let gravity accelerate you on the downhill.

Tom

[Felt]

Originally Posted by qbee42

Neither. Let the speed slip on the uphill side, and let gravity accelerate you on the downhill. Tom

Good Advise. I generally drive my G3, IV normally. I stay with the flow going up, not accelerating, at the crest of the hill I may regain any speed that was "bled" off going up, but if it is a long downhill, I find the "sweet spot" and let her coast. If the speed picks up too much, I retard it with the "B" setting, otherwise, I let her run free. As long as you are not driving 75-80 mph, I find I can achieve about 53 mpg on the Interstate, even in the mountains (where we live).

Good Luck

[a64pilot]

I would say if possible pick up a little excess speed prior to the hill, then let the speed decay as you climb it, the objective being to stay out of the power portion of the HSI. I would coast as much as possible on the downhill, use regen braking if necessary, but stay out of B if possible, B's function is to waste energy and I would want to recover, not waste if possible. Be cautious of safety of course, use B if needed for safety.

[lamontcranston]

That makes a lot of sense! Thanks!