Optimal RPMs for mileage

[unhuman]

New here with my relatively new 2009 Vibe (got it end of April). I've been driving to get optimal mileage and I think I've done pretty well. I've gotten between 30.25 and 33.25 mpgs in mixed driving so far. Not bad, since I'm supposed to be getting 26/32. My old Grand Prix I got 22 if I drove really slowly, the Vibe is much easier.Anyhow, I'm typically changing gears (manual) at about 2k RPMs. I lock in my cruise control at about 62. What is the optimal place to lock in cruise control to maximize my mileage. Also, would be good to know what the ideal speed is in each (higher) gear - 3rd 4th 5th.Thanks!!!-Howie

[Sublimewind]

The lowest possible... Problem is, you have limited choices.. unless you want to be one of those people doing 60 on the highway (70mph on the highway here)Welcome to GV BTW.. I always forget to start with that..

[goochsmooch]

On the tanks where I've had the patience, I've tried to shift ASAP as well, however, I worry that the engine might be pinging if I shifted at 2000 rpm's and it's hard to tell with all the sound proofing between the cabin and the engine. Don't you find that the engine lags too much when you shift that soon? As for locking in the cruise, when I'm striving for the good mileage around town, I try to get to about 65 km/hr and stick it into fifth (rpm's run just under 2000 at this point.) Seems to work for me. I don't speak this funny "miles" and "gallons" talk , but I have squeaked out nearly 650 km on a full tank - all city driving.Also, I think cruise may only be the most economical method in some situations. If you are fighting a lot of hills and trying to climb them using the method I previously described, I imagine the pedal would be to the floor. Just a theory though, as things are pretty flat out here.

[unhuman]

If I'm on flats or downhills, 2000 is fine. If I'm in the hills, I do tend to rev up a bit higher, and shift at 3000 or so. It does vary. If I have the A/C on, I also tend to rev higher as well, again, especially in the hills. The engine (I have the 1.8L) just does not have enough torque to push the compressor and the car at the same time at low RPMs, thus adjustments to my technique are required.

[wyatt89]

I usually get around 32 mixed city highway with my 04 gt. I shift at 2.5-3k since my engine is gutless down low. You don't have to give it a whole lot of gas, I usually just barely push the gas down and wait for it to get up to 3k and then shift, most people just mash the gas then shift, I believe that gets worse gas mileage.Also, if you are in the city or something and the speed limit is low you can give it gas in first and second, then just go straight to 5th.

[ehoff121]

For those with an auto, I faintly remember someone posting a chart showing optimal speed for highest mileage and it showed 40 mph in 4th gear (overdrive). I think that's somewhere around 1,500 rpm. I'll do a search and update the post if I find it.Edit: This is a poster's scan gauge result graph http://forums.genvibe.com/zero...46955

[star_deceiver]

I'm only on my third tank so the Vibe could be here or there, but in the Sunfire, cruising at 100 - 105km/h on the highway 6 L/100km (39mpg) could be coaxed out of her!Unless you like being tailgated and cut off by angry soccer moms, getting optimal mpg in the city is a real pain but yes, light throttle and short shifts rule the day!

[djb383]

A manifold vacuum gauge is the key to getting the best fuel mileage. The higher the reading, the better the mileage regardless of engine rpm. http://www.amazon.com/gp/produ...otive

[star_deceiver]

Got one of those! + you can get a decent looking one for less then $20.I teed mine into the vac line (can't remember what it goes to for the life of me...) right after the throttle body..... Does the 1.8L have an unused vac port on the intake manifold itself? (Sunfire has one, easily accesible too)