wifes 05 malibu 3.5 gas milage ideas anyone?

[van383]

looking to get a few more miles per gallon and i have never messed with these cars at all so any ides would help..thanks

[wkdivr]

I'm also having a hard time finding help/ideas on tuning these engines. If your I5 is basiclly the same as the Colorado's, look in the tune repository for the few tunes that have some mods to them. I did some cut, and paste, and I gotta say, I can feel a difference.

[n0dih]

I personally have found more consistent mpg with the higher octane fuel and tune for it. Everyone whines and cries about the fuel prices and premium being so much more, but when you ponder that it only costs you maybe $4 for the average tank more, which is only 1 gallon, even less in some areas, that comes up with a very small amount better mpg needed to actually become more cost effective to use over 87 octane. 89-90 octane could possibly be better, but you'll have to do your own testing.

Document it before, and then after, carefully and consistently. Don't calc in your head and guess #'s (like my friend who tells me his 454 Burb got 16 highway and 14 city mpg, come to find out he fills it up and when it clicks off he stops filling and calc's it that way, very very inconsistent). Get a log, log everything, ever change you make, average temp for the day, if rainy, dry, windy, traffic, if you were throttle happy, etc.

The things you can do are endless, but you have to determine what works and what doesn't too.

I have messed with higher rpm shift points and lower throttle vs lower rpm shift points (make it shift early, essentially short shifting) and even doing 2nd gear starts all day. I was most consistent with higher rpm light throttle shifting (within reason) and make my gearing do the acceleration work, not the engine torque (which consequently uses more fuel....). My SC3800 is essentially perm performance mode shift table and it is like that factory and I am getting 27-28 highway and 22-24 city so far.

Gears, make em work for you, they are adding more with the newer cars/trucks (6 speeds), the more constant you can get the rpms (like a CVT) the more stable the fuel delivery and consistent mpg will be.