How do I get the most mileage out of my manual-transmission car?
October 2, 2012 7:21 AM Subscribe
Can you help me understand, once and for all, what I need to do to get the best mileage out of my manual-transmission car?
posted by Scientist to Travel & Transportation (27 answers total) 5 users marked this as a favorite
This seems like it ought to be a really simple question and I feel a bit stupid asking it, but I get a lot of conflicting advice which to me is indicative of some kind of popular misunderstanding on the subject. Certainly my own understanding is rather hazy. I feel like I can trust the good people of MetaFilter to set me straight for good and all, so here I am.
I have a 5-speed manual transmission car, a 2002 Honda Accord. I am trying to figure out how I should use the transmission if I want to maximize fuel economy. I'm not talking about trying to maintain a balance of economy and power, and for the purposes of this discussion I am separating acceleration and cruising, assuming that I will never have to unexpectedly accelerate and that I will always have time to change gears if necessary before making a maneuver. I realize that in the real world this is not the case, and am just trying to simplify the problem conceptually for myself.
My current understanding is that if I'm cruising I should pretty much just drive smoothly, as you would in an automatic, and that I should be in the highest gear that the car is able to sustain so as to minimize RPM. This makes sense to me. Lower RPM = fewer combustions = less fuel used, right?
However when I try to confirm this I also hear a lot about using the transmission to keep the car in the most efficient part of its power band, which would seem to mean that I should be aiming for some optimal RPM rather than just the lowest RPM that my car can easily sustain for a given speed. Is this the case? If so, why? And how do I know what that optimal RPM is for my specific car?
When accelerating, I tend to adopt a similar strategy. I try to accelerate smoothly and gently, again as one would in an automatic, and I shift up as soon as the car is going fast enough to let me do so. This is again intended to reduce engine RPM under the assumption that higher RPM = worse economy.
Is that correct, or is there again some optimal RPM I should be aiming for when accelerating if I want to minimize fuel consumption? Is this the same as the optimal RPM for cruising, or is it different? How do I know what it is?
My theory on the subject is rather hazy and if anyone feels like they have a really solid grasp of it and can explain it in a clear and simple manner then I would love to know about it. Mainly though I'd be happy if I could just be sure that I wasn't unnecessarily burning fuel while trying to drive economically.
Thanks for helping me settle this one for myself.