what is killing my mpg??

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
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Mid Michigan
winter fuel, headwind, low tire pressure, dragging brakes, fuel system issue -- point is, it could be anything.
 
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RENODMAX

Dead Wrong
Mar 4, 2008
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Like Tom said it could be alot. I'm pretty big on mileage so I make sure filters are all clean, tire pressure is good, that i've got as little crap
in the bed/cab as possible and just general stuff like making sure everything is greased well. Biggest thing is to switch to efilive too. I get 23 mpg hand calculated on a 4" lift with 35s.
 

fast03

Active member
Jun 15, 2008
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Rancho Cucamonga
jordan what tire pressure do you run on those 35's? i keep getting 17mpg going approx. 75mph with 4" lift & 35's. i think those m/t atz's rated up to 65psi i run 52

Jonathan, I run 33's and get 19 at 75 depends on terrain. with the 4088 i have been getting up to 21 @65-70. I know when I go over 2k rpm no matter what tune my mileage drops immediately.
 

RENODMAX

Dead Wrong
Mar 4, 2008
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jordan what tire pressure do you run on those 35's? i keep getting 17mpg going approx. 75mph with 4" lift & 35's. i think those m/t atz's rated up to 65psi i run 52

I run around 48 psi. I got around 21 with my 4088. But I didn't try to tune it for economy at all.
 

Mike L.

Got Sheep?
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Vendor/Sponsor
Aug 12, 2006
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Like Tom said it could be alot. I'm pretty big on mileage so I make sure filters are all clean, tire pressure is good, that i've got as little crap
in the bed/cab as possible and just general stuff like making sure everything is greased well. Biggest thing is to switch to efilive too. I get 23 mpg hand calculated on a 4" lift with 35s.

I don't believe your mileage.
 

mmangels22

Monty Python Rules.
Feb 12, 2009
801
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San Jose, CA
23 mpg? Is that from the DIC calc or your own math? I average 17 or so.....a non stock turbo makes you gain 5 mpg's?

Do all your regular maintenance stuff IE change oils, filters, etc and then if its still the same could be the fuel you use. 15 mpg seems kinda low.
 

RENODMAX

Dead Wrong
Mar 4, 2008
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23 mpg? Is that from the DIC calc or your own math? I average 17 or so.....a non stock turbo makes you gain 5 mpg's?

Do all your regular maintenance stuff IE change oils, filters, etc and then if its still the same could be the fuel you use. 15 mpg seems kinda low.

Hand calculated as my post states. I have a stock turbo. Read through the thread.
 

coker6303

Keep Calm and Chive On!!
Aug 6, 2009
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Houston, TX
i have 245's on my truck and EFILive tuning by JoshH and it takes effort at 65mph to get to 22-23 and that is cruising only, I can't avg that for a full tank. I have found that I get less mpg if I stay below 60mph, seems to be much happier at 65 but not over 68mph.

Here is where you should be based on my experience with my truck (43k miles, LMM 4x4, 245x75r16, CCSB, 400rwhp EFI tuning by JoshH)

65mph - 22mpg cruising

70 mph - 20mpg cruising

75 mph - 18 mpg cruising

I specified cruising because these are the mileages that I see while maintaining those speeds, your tank avg. will most likely be less unless you cruise for 1 full tank with no city driving or idling. If you are all alone on the road expect your mpg to fall slightly because of wind drag. If you are on the interstate behind a truck, you can push your mpg slightly higher. Wind drag is a big factor in mpg.

I'm not buying the 23mpg tank average on 35's unless you are coasting down hill or being towed! lol

DMAX FTW!!:D
 

fast03

Active member
Jun 15, 2008
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Rancho Cucamonga
I actually have gotten 23 one time and 26 another. the time I got 23 I was running stock 245's and runing 55 for 300 miles and when I got 26 I had a really strong tailwind for 150 miles. generally speaking I get around 19-21 running 65-70 for my so cal commute which is along the foothills so some up and down, 46 miles round trip.
 

RENODMAX

Dead Wrong
Mar 4, 2008
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I actually have gotten 23 one time and 26 another. the time I got 23 I was running stock 245's and runing 55 for 300 miles and when I got 26 I had a really strong tailwind for 150 miles. generally speaking I get around 19-21 running 65-70 for my so cal commute which is along the foothills so some up and down, 46 miles round trip.

that's similar to what I had steve. I believe you :D
 

SmokeShow

Well-known member
Nov 30, 2006
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Lawrenceburg, KY
Like Tom said it could be alot. I'm pretty big on mileage so I make sure filters are all clean, tire pressure is good, that i've got as little crap
in the bed/cab as possible and just general stuff like making sure everything is greased well. Biggest thing is to switch to efilive too. I get 23 mpg hand calculated on a 4" lift with 35s.

:eek: you wanna share that tune? :hello: :hug: :beer


Oops, I see this has been discussed. I just got excited and immediately replied without reading the rest of the thread... I'm still interested in trying it though. :D
 
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