Normal gas mileage for me has been ~20 MPG in my 535 im.

A while back I tried driving really really easy to save gas, like 5-10% throttle as a max, accelerating slowly everywhere I went. Worked okay but it was too hard to drive like that in a 535 5-speed, seemed like a waste. I could push up to 23 MPG at a max but couldn't sustain it because of my heavy foot.

Bill R. posted something a few years back about accelerating up to speed at 90% throttle but I never got that to save any gas. UNTIL I learned the second half of the secret... coasting.

I still drive like a bat outta hell but only until I get up to speed. Then I put it in neutral and coast as long as I can. Works best when traffic is light or on the highway/freeway. I've been sustaining 22 MPG the past few tanks, and that is pulling HARD through the first few gears up to redline, like the M30 wants to be driven.

My guess is that it works because (put your statistics hat on) MPG is a one-sided distribution. You can't go below zero MPG but you can theoretically approach a very high MPG. If you spend a little time at, say, 5 MPG while you rocket up to speed, you can coast at, say, 100 MPG (idling while the car coasts) and get a higher average. Not a huge difference but 10% = $7 a fill up, something to put aside for the new clutch I'll need from all the extra shifting.

Haven't tried a tune up and air in the tires, that's next...