Going up big hills

[Hockey4mnhs]

I live were there is little to no trafic in the morning. I have huge hills on the way to and from school. Is it better take your time up the hill or try to get up it as fast as you can. I can literaly go 5mph up it if it helps Fe or 60 because no one is behind me or in front of me.

[Peakster]

I used to think that gearing down and taking the hill at a higher RPM was best when going uphill. Now that I have a Scanguage, it turns out that it's always better in my car climb the hill in the highest gear, even if I have to floor the gas in that gear to get to the top.

[diamondlarry]

I have kind of came to that same conclusion. I have also noticed that when taking off from a corner that the GPH(gallons/hour) doesn't rise any faster during large throttle inputs in the highest gear compared to lower throttle inputs in the same higher gear. The GPH really only starts to go up when the engine rpm's start to climb.

[diamondlarry]

Originally Posted by theclencher

Is this a failure of measurement methodology? At any certain engine rpm a larger throttle setting will be consuming more fuel, right?

What I have noticed, according to the SG that is, is that throttle setting doesn't seem to have as much of an effect on gallons/hour as do rpm's. Even at higher rpm's, the GPH doesn't rise the instant that the throttle is floored. It only seems to rise when the rpm's start climbing.

[JanGeo]

The reason for that limit is the engine is over asperated meaning that it can't suck in any more air than it is at part throttle because it already has no vacuum left. Raising the RPM allows even more air to be sucked in and thus more fuel to be burned with it.

Climbing a hill comes under the same limitations only the MPG gause can show you exactly what is the best way to go up the hill . . . although is seems that the less rpms on the engine per distance traveled the better the MPG so the tallest gear. Unless you want to give the engine a little break and let it rev a little.

[thisisntjared]

so then is it better for fuel economy to gain some extra momentum before the ascension and let the speed bleed off as you reach the summit in top gear?

that has always been my strategy and i try to work things out such that i am at the summit at 40mph(any lower in top gear and i loose smoothness).

[SVOboy]

Originally Posted by thisisntjared

so then is it better for fuel economy to gain some extra momentum before the ascension and let the speed bleed off as you reach the summit in top gear?

that has always been my strategy and i try to work things out such that i am at the summit at 40mph(any lower in top gear and i loose smoothness).

That is the way of those in the know, I do believe. Lose going up and gain going down.

[Peakster]

Originally Posted by diamondlarry

What I have noticed, according to the SG that is, is that throttle setting doesn't seem to have as much of an effect on gallons/hour as do rpm's. Even at higher rpm's, the GPH doesn't rise the instant that the throttle is floored. It only seems to rise when the rpm's start climbing.

I can also confirm that. My Geo uses around 1.8gph when the gas is floored uphill in 5th gear, going around 50mph. Not a giantly huge leap than the usual 1.0gph required to keep 50mph on a flat surface. If I were to shift into 4th at that speed, I would be well into the 2.4+gph region without flooring the gas so the lower rpm is the way to go.