Gas Mileage MPG : SD vs MAF

90mustangGT

I felt sorry for girls because
Founding Member
Jan 15, 2002
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Dallas, GA
Which gets better fuel mileage, Speed Density or Mass Air Flow on mild or stock engine cars? I have everything to do the swap, but I don't need to, so I haven't. My old car got decent gas milege, and although it was a 5-speed, it was much better than this car. I am going to convert it to the 5-speed from AOD very soon, and after than I might install my A9L and the rest of the harness, including the 140mph speedo as well as a few other parts.
 
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It's all in the tune.... It doesn't matter which way you go.

I am sure with a tunable ECM you could do a lot to get better fuel economy.

All things being equal, in theory, MAF will yield better economy.

This is what I am figuring, because MAF is an active fuel metering system that mixes fuel based upon live data coming in. It's an active system. SD is a passive system that meters current fuel based on previous readings coming from less sensors. So it's a passive system. The worse part is it bases how it meters fuel in an active way is based upon the MAP sensor, and that isn't very reliable. So the SD guesses and the MAF knows. I need to convert my car over. It's going to be easy considering I have all the stuff. Miss a 140mph speedo. I am going to pass the sniffer and then have at it.