Mpg'ers Beware Of Leveling Kit And Tires

Ron505 · July 28, 2009

This may be not be everyones experience, but I took at least a 2 mpg hit when adding 18x9 and 305/60-18 to my ride. I was averaging 18-19 mpg on the highway, and now I'm at about 16.3. This was all calculated over the last 3 weeks. Similar weather, same climate. I'm hoping a tuner can get me closer to where I was....if not, the wheels may be coming off and up for sale.....prolly not, but hey...

Spurshot · July 28, 2009

As they say; there's no free lunches!

Zembonez · July 28, 2009

I lost about 1.5 mpg when I went to my 20s. It does take a toll.

zackafee · July 28, 2009

Did you recalibrate it for the larger tires? if not, the trip odometer thing is off and you are getting an incorrect mileage reading.

Zembonez · July 28, 2009

Did you recalibrate it for the larger tires? if not, the trip odometer thing is off and you are getting an incorrect mileage reading.

Oh yeah. I've since gone to 3.73 gears too. Nothing is stock anymore!

C. Charles Hahn · July 28, 2009

I think the wheels and tires are probably more to blame than the level kit... you added more rolling mass and rolling resistance, which is a more significant change than 1.5-2" of ride height... or at least that's my take.

Anyone else have any experience with the level kit dropping MPGs by itself?

Ron505 · July 28, 2009

Did you recalibrate it for the larger tires? if not, the trip odometer thing is off and you are getting an incorrect mileage reading.

Funny thing is, my odometer was reading too fast before, about 2-3 miles over at 70 mph. Now it's right on with my wifes car and my gps. Are GPS's the true speed? The 305's only added 1" of diameter. I too believe that the width and total wieght of the wheels and tires has a bunch to do with it.

How much can I get back with a programmer? I can tell the shift points are pretty far off. Any suggestions on brand and where to order?

2COR517 · July 28, 2009

Taller tires take more force to get rolling. Wider tires have more drag. More aggressive tires usually have more drag. Lifting the truck has changed the aerodynamics, pushing more air under the truck - more drag. The lift is probably the biggest factor here.

Ever notice how low race cars are? And the dam on the front is getting the air to go around the sides, not under. Even passenger cars and pickups have an air dam as low as practical to get air around the vehicle, not under.

Spurshot · July 28, 2009

Both, lifting and the taller tires are a hit to the mileage, I agree with Palmer. Which is more detrimental? Probably has to consider how the truck is driven. If a guy uses it mostly for highway, the extra drag (aero) would be the bigger swinger. If mostly driven in town below 40 mph or so, in stop and go, tires might be the bigger influence. The aero drag forces at 60 mph are, what?, 4 times as high as 30 mph.

2COR517 · July 28, 2009

Chuck - you are correct. Doubling the speed quadruples the drag. That's why you get so much better mileage at 55 than 65 or 70

mhenshaw · July 28, 2009

It's the tires, I lost some gas mileage going from the stock 265 to alittle 275, but each tire weighs about 12 pounds more. The rolling resistance and weight of the tire kills gas mileage. When I put my leveling kit on I didn't even lose half a mile on gas mileage.

AgDoctor · July 28, 2009

I lost some mileage by going to a 275 tire(mud tire) and maybe a little from the leveling kit. I lost a little by removing the front air dam, but all things done I still wouldnt have it any other way because of the stance and size of stock tires, suspension, and air dam level. It looks similar to the 2500HD stance now. I have the 18's, but I think that they rolling weight has more to do with stop and go mpg, where as the tire diameter has more to lower mpg on straigh-aways. I dont believe that the leveling kit and air dam removal would even amount to 1 mpg loss.

AgDoctor · July 28, 2009

i wanted the BFG 285/65-18 but they were so damn heavy and E rated and I thought tha would kill more power and mileage than the 275/65-18 C rated and they were only 6 pounds heavier than stock each.