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Old 11-08-2012, 01:50 PM
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importance for mpg gain?

so i have an 08 4.7L 2nd Gen WK laredo
before i went to the lift and larger tires I obviously had better mpg.
those were only a couple factors here.
this is where I was stock:
-srt roof rails (for some reason came on it)
-stock suspension
-stock fortera 245/65/17s
-air dam on
basically all bone stock with srt roof rails
With this setup, I was getting 19-19.5mpg average

most of my driving is about 65-70miles a day highway(all my weekday driving).. I do city driving and some backroads and wooded trails on weekends.

I went ahead and started modding my WK (which I love now) with:
-replaced SRT rails with stock wk raised roof rails... no crossbars (only on in spring summer for thule kayak racks)
-2" daystar BB lift
-1.5" spidertrax spacers
-265/70/17 cooper AT3's
-removed the air dam

my mpg is down to 15-15.5 average understandably. BUT, i would really love to get back towards 20..

what would you guys say IN ORDER OF IMPORTANCE and keeping prices in mind to be most economical/practical spending... would be the best things to do in order to get this back?

I know i can go with a CAI and a tuner... i know people use the fastman ported TB to go along with it to get better response as well...some people say exhaust systems...but what would you say the best things to get,and what to start with first to get my MPGs with my engine setup back up towards 20mpg again??..everything under the hood is stock as of now. and im not well versed in performance/engine/tuning mods at all.
Thanks.
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Old 11-08-2012, 02:34 PM
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Re: importance for mpg gain?

tires and lift are brutal on mpg.
I know it would "look funny". But I'm curious what would happen to your MPG if you just threw on the stock wheels/tires/airdam, because I suspect the lift is what is hurting most. If it improves the MPG, perhaps running the stock wheel/tires/airdam for the 80% of time you drive on paved roads is worth doing. Then install the big wheels/tires on weekends when you go wheeling. This is what I plan to do next year. I had a hypertech programmer on my durango, I think I got 10% improvement in mpg - of course the programmer cost me $250.

the other thing to keep in mind is that with larger wheels/tires, your odometer will say you haven't driven as far (unless you've corrected the odometer), but you've used the same amount of gas as before.
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Old 11-08-2012, 02:43 PM
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Re: importance for mpg gain?

honestly the throttle body by itself did nothing for me mpg wise. to be honest i could barely tell it was there. i ran that and the exhaust first and i dont remember my mileage but it wasnt impressive.. once i added the tuner i gained some of my mileage back due to the adjustment in the speedo and the use of the 91 performance tune. found a deal on the AFE thats for sale and thought it would compliment the whole set-up. i know i was getting closer to 20-21mpg when i ran the 91tune and all the supporting mods.

when gas prices were kinda ridiculous i went to the 87tune and my mileage took a dump, i was getting close to 16. now for some reason when i ran the stock tune, intake, exhaust, and throttle body id get around 18 or so when i kept my foot out of it. thats on 32s.

it all helps the other mods when you dont drive like an asshole. lol
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