Going from 18" to 20" stock rims?

[titan01]

My 2015 Sierra came with 18" rims. Is it just a simple case of swapping out to a 20" stock rim or is there a different ECU'tune' for the different rim sizes. The tire diameter is pretty close for stock sizes, the 265/65/18 is 31.6" and the 275/55/20 is 31.9".

Thanks for any info.

[LongrangeLauber]

As long as the tire height is the same there is no need for a retune. Doesnt matter about wheel size, only tire height (measures overall rotations per minute)

[ShotgunZ71]

I swapped my stock 18s for the 20s. Everything is still spot-on. Ironically, the old 16s that were 265/75/16 are also the same diameter. You're basically just trading sidewall for rim.

[amxguy1970]

I swapped my stock 18s for the 20s. Everything is still spot-on. Ironically, the old 16s that were 265/75/16 are also the same diameter. You're basically just trading sidewall for rim.

And weight and mpg as well...

 

Tyler

[ShotgunZ71]

And weight and mpg as well...

 

Tyler

The increased weight of the rims and decreased fuel mileage is near negligible. I've not noticed any change in mine. Come to think of it, with the level kit and 20s, my fuel mileage is roughly the same. Not saying it didn't drop a couple tenths, but nothing that stands out. I'd say less than 0.5 mpg, probably. If I went with a much larger, non-O.E. type tire, I'm sure mileage would have taken a nosedive.

[obrien19]

I just upgraded to the 20 inch replicas last week and bought stock tire size, nothing has changed, and nothing needed to be programmed.

[titan01]

Great info and good to know, thanks guys!

[jamin87ss]

Same here, a/t 18's-a/t 20's no issue no fuel mileage loss