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What's up guys,

I am putting together a 9-11" CST Lift on 38" Toyo Open Country M/T's right now. I am getting around 18-19 MPG on my duramax right now depending on how heavy my foot is.

What MPG loss should I expect from running this size lift and tires?

Thanks
 

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What's up guys,

I am putting together a 9-11" CST Lift on 38" Toyo Open Country M/T's right now. I am getting around 18-19 MPG on my duramax right now depending on how heavy my foot is.

What MPG loss should I expect from running this size lift and tires?

Thanks

If you don't re-gear it will depend on how you use the truck. If you cruise the freeway at 55-60 your milage may actually go up because your RPMS will be really low.):h

Running the stock 3.73's and 35's on a 6" lift I'm seeing 15-16mpg mixed freeway and around town. I see 18 to 19 on the freeway cruising at 70mpg.

I would think about a re-gear going with 38's, maybe 4.56's or at least 4.10's to leave you some launching/pulling power.

Just my$.02,

Chris
 

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I have seen the same as whippled. But the wind really seems to be the deciding factor. I was driving 80 mph into 35-40 mph winds and got 10. I had around 2500-3000 lbs on board.
 

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isee about the same 12 - 14 mpg 16 on the highway
 

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With my lb7 and 37's and stock 3.73's I got 20 mpg on the freeway and 14-15 around town. Now with my lbz on 40's I get 13 mpg around town and 15-16 on the highway even after putting in 4.88's. Both have similar mods, exhaust programmer. The biger lift and tires honestly hurt mpg even with a gear change.
 

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Dropped from about 17 to 15, combination city/highway.

But, it's also winter here in AZ, some mornings it's below 40 degrees and I was noticing a drop when it's cold anyways, hoping it will get better in the spring, lol.

6" Pro Comp / 315/75/17
 

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i was getting 18-20 before lift and after 15-17 mixed driving. i have 37'' with 3.73 and a regular cab. you will not see an increase in mpg regardless of RPM on the highway.
 

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10-12 is taller than I am as far as wind drag, these guys are getting better economy than I am. I get 14.9 at best no matter how fast, slow, pull or wind. I drove from Dallas to Omaha and still got 14.5-14.9 hand calculated. I have never seen more than 330 miles on a tank of fuel. I think it depends on your fueling habits (top off to top off) or top off to pump stop. Such is life, live and learn.
 

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I lost 2 MPG compared to stock. Even though the RPM's drop w/the diameter change the rolling resistance and wind drag increase and milage will get a little worse but not much.
 

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I saw about the same difference. I went from getting 16-17 for a mix of city/highway driving to getting 14-15 when I went from the 245's to the 315's.

Towing my 10K trailer I went from 9 down to 7.5.
 

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Wow, I don't even get you lifted/big tired guy's city mpg's on the Hwy with my non lifted Dmax w/ 265's. :confused:
 

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Even after you install a higher gear to comp for the larger tires it all comes down to wind drag,the wind is getting up under the truck now due to the front end being higher or even with the rear compared to stock height (nose down rear up) wider tires come into it some,a tire thats 9" wide compared to a 15" or wider tire will wind drag some also.
 

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Yea, but they look cool! Read some posts about the wimpy 245's He!He!He!

 

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I just got my 7" Cognito installed with 35" M/T's. I have not driven much but have noticed a drop in MPG's. I was getting 15-16 average but i expect to go around 12-13 MPG's with the lift and tires.

IMHO, the look is definately worth it.
 

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I just got my 7" Cognito installed with 35" M/T's. I have not driven much but have noticed a drop in MPG's. I was getting 15-16 average but i expect to go around 12-13 MPG's with the lift and tires.

IMHO, the look is definately worth it.
 

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14-16, just depends, my rig:

 

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I get any where from 12 to 14 in town and 15 to as much as 18 depending on the wind and speed. I live in Vegas where it seems that if you leave town your against a head wind and by the time you return the winds shift and again I am driving against a head wind so I seem to be getting 15/16 more than 18 these days. But when someone says "cool truck" it makes up for the loss...):h
 

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Mines lifted 6 inch with 35's. I get steady 16-17 city, 18 or so on the highway.

13-14 when towing anything.
I pull about the same on the highway,in town I get terrible mpg's,I'm always screwin around .:cool:
 
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