Switched from 265/65 to 275/70 and...

d9avey · January 12, 2018

Mornin' friends!

I recently purchased a 2015 Silverado z71 and realized that the tires are too small/not aggressive enough. I took off the 265/65/18 tires and threw on some BFG AT KO2 275/70/18 tires.

What's strange is that my average dropped from 18.8 to 13.7..........what!!!!!!??????!?!?!?!!!!! No way does this happen with this small of a tire change, no? Am I wrong?!

Also, what should the PSI be? It says max 80 but I put 40 in it.

Thanks much!

MB2008LTZ · January 13, 2018

What are your driving habits? Were the tires you took off far less aggressive than the BFG's. I run 35 lbs in my 275/60/20's. While I am not sure of why the drop in MPG, it is very possible. I only get about 10 MPG on my 5.3 with my tires but I also have a supercharger and drive it like I stole it...lol.

d9avey · January 14, 2018

On 1/12/2018 at 6:52 PM, MB2008LTZ said:

What are your driving habits? Were the tires you took off far less aggressive than the BFG's. I run 35 lbs in my 275/60/20's. While I am not sure of why the drop in MPG, it is very possible. I only get about 10 MPG on my 5.3 with my tires but I also have a supercharger and drive it like I stole it...lol.

Hahahah I drive pretty normal just to save every drop of gas that I can lmao! I heard from BFG and they told me 50 psi for normal driving?! I've noticed it a tad bit rougher in general but I don't care, I am getting better mpg! Ha!

swathdiver · January 14, 2018

Well, you went from a tire that's mathematically 31.56 inches tall and 639 revolutions per mile to one 33.16 inches tall and 608 revolutions per mile. 40 psi is kinda soft are you saying that you now bumped the air up to 50 psi and noticed an improvement in mpg already?