Let me start of in saying the car ran great!
M6 3.42
CC503
918s
Promag 1.6 RRs
PP heads (minor, mostly in the exhaust ports)
3 angled
11:1
LTs
magnaflow catback
ORY
MadZ28 tune
MSD cap and rotor
Magnacore wires
K&N CAI

got 347.7miles before fill up and it averaged out to just barely over 23mpgs
the tank before that I got 16.5 mpg in the city, I have a heavy foot in the city, but for running the air and driving in the rain the whole 200 miles back @ 65mph
I drove at about 75mph on the way there with a 115mph run to catch up with my buddies (I had to stop and put the T-tops on, it was starting to rain)

So 23mpg...I guess I will take it.

 

Any HP #s or track times?

Still that is awesome MPG.

 

haven't had it to the dyno or to the track

 

Nice man, I actually recorded my MPG this weekend too. I was getting 27mpg, stock car (intake, full exhaust, M6) with a light pedal.

 

i have gotten 23.5 out of mine with a #2 missfire when all stock and cruise set at 75 and a/c runnin.

its getting further and further away from stock now tho so i can only hope it starys around there... hell 20+ and im sure ill still be happy.

 

Yep M6's are great on the highway. I got 25 mpg turning a supercharger for 300 miles.

 

NIce mpg, im hopeing to be about there, but I know I won't lol.

 

I wish it was better

 

Impressive I was getting 11-12mpg on a good week with that cam but I do have a stalled auto which doesn't exactly help.

 

Got 28.8 on a trip 90 miles and back. Was doing 66mph, 6th gear tachin 1600rpms. Had also aired up the tires to 40psi in the front, 38 in the rears. Washed and waxed the car too to help aero.

 

^what mods?

 

slomarao any mods?

 

Ya, pretty much every bolt on except a ewp. Light work done to the heads and intake, pretty much just gasket matching. Koni's on all 4 corners, sub frames, lca's, tune, 3.73's, eaton diff, alum ds, new hi flo cat(magnaflow). The car is not lowered. Which would help.
The biggest thing which helps so much is the extra air in the tires and just getting done waxing,glaze, compound, claying the car.

Im putting on springs, a panhard rod arm, re location brackets and after I adjust the camber and caster to more road race settings I think I can break 30mpg's. I also need an alignment which will help me with my goal.
There was a thread about doing it a few weeks back. I think the best the guy did was 32mpg. Oh and I re balanced the tires about a month ago. Plus i have re built the top half of the motor due to headgaskets and also replaced everything. O2's,plugs, wires, fuel filter, rebuilt heads, new opti and waterpump, etc.

The thing is you have to leave the car on cruise control. No touching the gas, I set it on 66 and left it.

 

You actually can get better mileage using your foot instead of cruise.

 

I kinda agree, explain your reasoning though