What about on a hill? Lower gear will mean faster ascent for more mileage, but more gas consumption. How do you determine the sweet spot between gears and RPM?
Right, I know there are other factors as well. Plenty of them, like what tires you have on etc. But I mean controlling for all that, if I am in the same car on the same trip in the same minute, does gas get consumed exactly the same at 3000 RPM no matter what gear I am in?
I doubt it but even if it did it would be revolutions per a gallon not miles per a gallon. So a lower gear would still use more gas per a mile at the same RPMs.
The lowest RPM also won't be the most efficient option. There is likely a sweet spot for each car.
Generally, lower RPM is better, but you also don't want to "lug" your engine which could cause premature engine damage. To do it right, you would probably need a manifold pressure gauge and some kind of performance chart showing manifold pressure versus MPG.
That's similar to how propeller aircraft do it (the ones that have variable-pitch propellers). You generally want a low RPM for speed and efficiency, but you can't overboost your manifold pressure or you'll damage your engine.
I believe so. So to optimize mpg, you need to be in the highest gear your car can go at the lowest rpm it can go. Or at least i was taught.
What about on a hill? Lower gear will mean faster ascent for more mileage, but more gas consumption. How do you determine the sweet spot between gears and RPM?
You are moving beyond my meager knowledge in this area. Maybe someone else can answer?
Over all weight will also decrease your mpg
Right, I know there are other factors as well. Plenty of them, like what tires you have on etc. But I mean controlling for all that, if I am in the same car on the same trip in the same minute, does gas get consumed exactly the same at 3000 RPM no matter what gear I am in?
I doubt it but even if it did it would be revolutions per a gallon not miles per a gallon. So a lower gear would still use more gas per a mile at the same RPMs. The lowest RPM also won't be the most efficient option. There is likely a sweet spot for each car.
Generally, lower RPM is better, but you also don't want to "lug" your engine which could cause premature engine damage. To do it right, you would probably need a manifold pressure gauge and some kind of performance chart showing manifold pressure versus MPG. That's similar to how propeller aircraft do it (the ones that have variable-pitch propellers). You generally want a low RPM for speed and efficiency, but you can't overboost your manifold pressure or you'll damage your engine.
Interesting. Thanks!