DODGE RAM FORUM - Ram Forums & Owners Club! - Ram Truck Forum - View Single Post - Leveled, new rims, new tires... now horrible gas mileage
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Old 05-12-2013, 11:03 AM
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NWRQC NWRQC is offline
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Join Date: Dec 2011
Location: WA
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Vehicle: 2007 RAM
Engine: 2007-2011 409ci (6.7L) Cummins Turbo Diesel 350hp 650lb/ft
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Originally Posted by Thet View Post
I just leveled my truck, got new rims (17x9 steelies), and added new tires (315/70R17) and now my computer is saying I'm getting about 8.8-9.2 MPG in town. I'm not driving it like an idiot, so I know it's not my foot. I know the rims and tires are heavier than my stock 20" rims/33" tires combo, but would that make THIS much of a difference? I was getting about 14 MPG in town. On the highway, my MPG goes up to about 12. I have the 3.92 gears.

Any ideas?

When will the new tuners be available for the 2013 models? I for some reason thought I remember them not being out quite yet...
You're new tires are about 4.5% larger than the old ones so that will throw the already unreliable computer off even more. As the other have said, the dealer can correct that, but im not sure how much room they have for adjustment. A tuner would fix that as well.

Originally Posted by ADA16 View Post
Hey everyone why would correcting is speedometer help his mileage?
(I am also thinking about leveling and getting bigger tires)
Because this computer thinks that he is driving less distance than he really is. His hand calculated milage probably didn't change much, but the unreliable computer calculated fuel mileage is going to be off.
2007 6.7 | EFI-Live | Draconian tuned TCM | T4 S366 | ARP | AFE | Fox | Carli
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