M52 + 6sp + 3.15 = 33mpg

[dinanm3atl]

How you accelerate and throttle control on the highway make a big difference.

[nrubenstein]

How you accelerate and throttle control on the highway make a big difference.

*shrug* I can get 20mpg in my truck and 24-28 in the E46 M3 (and into the 30s in Mike's M54B30 528iT).

According to the wideband, my cruising AFRs are right around stoich, so my O2 is good. I'd still like to know how you guys are doing so much better. I suppose it might be interesting to look at the tune.

[jahnaboi]

Driving to save gas is no mystery. =P I have a light foot and only use minimal throttle.

[nando]

I use the clutch/engine to slow down a lot, when you're engine braking the injectors are turned off so you are using no fuel at all.

I also try to draft behind trucks. Another factor is the fuel, you will get significantly worse fuel economy if the fuel you're using has ethanol in it (E10).

[nrubenstein]

I use the clutch/engine to slow down a lot, when you're engine braking the injectors are turned off so you are using no fuel at all.

I also try to draft behind trucks. Another factor is the fuel, you will get significantly worse fuel economy if the fuel you're using has ethanol in it (E10).

Now that is a good point. We only get the shit gas here.

I only draft in the truck. It's not worth getting more rick chips than necessary in anything else. I don't generally engine brake per se, but I keep the car turning in gear for as long as possible to avoid idling it inb motion.

[euroshark]

I use the clutch/engine to slow down a lot, when you're engine braking the injectors are turned off so you are using no fuel at all.

Exactly! I'm sure that's how I get such great mileage in the mountains. I might only be getting 15mpg up the hills but if you are using no fuel on the way down it more than makes up for it.

[Jean]

Haha... I love my m30 mpg....15mpg-22mpg FTW haha.

[iamsam]

my 1991 318is gets 30 mpg avg pretty consistently, with me driving back roads to school/work and back every day. mpg prob gets worse on the highway, aerodynamics sucks and being at 4k rpm to match speed w/ surrounding cars doesn't help.

[Wh33lhop]

Exactly! I'm sure that's how I get such great mileage in the mountains. I might only be getting 15mpg up the hills but if you are using no fuel on the way down it more than makes up for it.

You get 15mpg in the mountains? I'd get like 8.

[euroshark]

You get 15mpg in the mountains? I'd get like 8.

Just an arbitrary guess. Could be 5 on the way up for all I know but the averages calculated after filling up tell the whole story.

[nando]

I got my best mileage ever driving across Stevens pass. about 380 miles on that tank.

[Ryann]

Any of you 30+ guys using a GPS for miles traveled numbers? Why are my calculations slightly better than the original spec'd EPA rating (19/25) vs. ridiculously beyond? You guys are either running rubber that is well short of the factory rolling diameter or burning dangerously lean. I'm not trying to be a dick here but 37 mpg's from a 24v BMW 6 cyl/4.10 diff. is not real unless you were driving downhill the entire fucking tank.

My m42 is well sorted, and I don't drive like an asshole btw.

[Bimmerman325i]

odo reading / gallons filled = mpg, no other way to calculate it.

[Ryann]

^Miles traveled on a GPS unit is much more accurate than the odometer reading, particularly for those of us who are rolling on undersized tires. For example the stock rolling diameter for late models is 610mm or 24" (195/65/14). I'm running 205/50/15's which are 587mm or roughly 23". My odometer counts more miles than I am actually traveling, so if I were to base my mpg's on the odometer it would be overly optimistic.

[netcsk]

My daily gets ~45mpg. Good ole Jetta TDI.