Does anyone have any input on installing 20" wheels on my truck? I am looking at upgrading, but by my calculations, there will be about 30lbs/wheel added to the rotating mass if I install 20x9 w/ 285 nitto's. I measured my stock wheels and they are 71lbs. I called Nitto and KMC and asked them the weight of their wheels and tires and added it up and they will be about 100lbs/each. This seems like such a large difference, I am wondering if they will be too heavy and cause me to lose 1-2 mpg.

So my question is, who has experience in the mpg difference by upgrading to 20" wheels and how much weight the wheels are? Any help is appreciated.

 

Im not a diesel guy but i do have 20s on my hemi and i would give anything to chuck them over a bank and go to 17s.I hate them and especially in the winter.Way to much rubber on the road for upstate NY winters.I am always in 4 wheel drive,it drives me nuts.For the couple miles per galleon u might get with the 20s over 17s i would be more than willing to give it up.Some say over in the 3rd Gen section you can even gain a little power with the 17s over the 20s,which sounds logical.So not only will you gain rotating mass by adding 20s,you also add outside diameter which is gonna take more power away.

 

The width of the tires not the height will make more of a difference. More tire on the road equals more drag, more drag equals lower mpg. The height of the tire will in essence change your rear gear ratio. depending on your current rear end ratio it might either increase or decrease your fuel mileage. The taller the tire will increase your ratio and conversely the shorter tire will lower the ratio. depend on how your motor is running and how you use the truck will determine your personal results

 

Little to no change in mileage when I swapped from my stock 17s and 285s (33") Toyos to my 20s and 305s (34") and there was little to no change from stock to the 33s.

I love them. Defiantely makes the truck look 10x's better

 

Larger wheels require more power to turn, which results in lower fuel economy. We're talking a minimal amount of difference here on a rig that has 600+ lb-ft of torque, so you may not notice it.

They also need more brake power to stop, however the shorter sidewall tends to flex less and typically low profile tires have stickier compounds than economy tall/skinny tires, so there's more grip available.

Larger wheels will help you in the corners, but hurt you in the straights both starting and stopping, given equal tire width/diameter/compound and even weight.

When you add more weight, it will compound it that much more.


Personally, I wouldn't worry about it. I don't know that you'll be able to tell. You might lose 1mpg, but I doubt more than that.

When I went from 235x85r16 to 35x12.5x16.5 on my 86 I didn't lose any mileage - but I also swapped out the cam, carb, intake, distributor, ecm, coil, and added headers. Power was way up, economy was the same, tires were WAY heavier and larger.