what is killing my mpg??

Sep 10, 2008
1,072
0
36
Morehead City, North Carolina
x2 on anything over 2000rpm's. Seems to just plummet. With 285's and no lift w/ 4088 I saw 23mpg--65mph and now 35's it's around 19. I was pretty surprised at the adverse affect tire size had with respect to mileage. Believe it or not, I get my best mileage on my hot tune....weird
 
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Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,556
5,611
113
Phoenix Az
my truck cruising at 75 with the PPE on lvl 10 i usually average about 20-21 mph hand calc (dont have that fancy, incorrect DIC crap lol). This is with cruise control on, clean air fliter, all synthetic oils, new fuel filters, and no wind.

Course as soon as i hit the go pedal to pass someone up one of the hills all this balck stuff comes out the back and fuel mileage drops??? My mechanic and i were thinkin its runnin too rich and has lots of carbon build up :D:rofl::happy2:
 

mmangels22

Monty Python Rules.
Feb 12, 2009
801
0
0
San Jose, CA
Hand calculated as my post states. I have a stock turbo. Read through the thread.

Ok so I understand that however is this one highway occurence that you got 23 mpg? Because I do not believe you average 23 mpg you are either not being truthful or somethings being miscalculated.
 

RENODMAX

Dead Wrong
Mar 4, 2008
3,602
0
0
This is my average mpg. He said his average is 19-21 which is what I'm referring to. I get 23 mpg on average hand calculated as I said. I'm tuning mitchs truck he'll report back.