Will tire/rim Size Change throw a code

gmyeah · February 16, 2015

I have a 2008 sierra z71 that I'm thinking about trading in on a 2015 sierra z71. I have two sets of tire/rims for my 2008.......both 265/70/17. One set up is for winter with Blizzaks on steel rims. I'm happy with this setup, but it seems like if i get a 2015 z71 the only tire option is 265/65/18. With the slight difference in size....would the 2015 sierra throw a code when i put on the winter setup, 265/70/17. I'm pretty certain the lug pattern would line up and everything would fit.....but how smart is the truck with that small change in tire size. I know there's lots of folks that would buy my winter setup quicklike, but I bought it only a few years ago and want to use it on my new vehicle if possible.

my other option is to get a non-z71 4x4 with the 17" option....but i do like the z71 setup.

thoughts?

FuelHauler87 · February 16, 2015

Doubt it would throw a code only would be Speedo difference

SouthernSilveradoGuy85 · February 16, 2015

It's not going to throw a code. The only thing is if you go with a different tire height (not size in general, actual tire height) then the speedo will be off a little. I believe those 2 tire sizes are the same height. If you want to make sure then go here http://www.rimsntires.com/specspro.jsp. It has pictures of the rim and tire differences and it also tells you any speedo difference.

I just looked, the 17" rim tire will only be .2" (2 tenths) taller but the speedo difference will be so minimal that you won't notice.

Doug_Scott · February 16, 2015

Diameter of 265-65-18 is 31.5 inches, the 265-70-17 is 31.6 inches. Difference in circumference is about .19 inches. You will not have any issues.

gmyeah · February 17, 2015

great info...thanks. and thanks for that site mentioned in the above post as well.

Doug_Scott · February 17, 2015

The site given in message #3 has a nice tool for comparing wheel changes as well. I use this site for tire size differences http://www.tacomaworld.com/forum/tirecalc.php I find it easier to use for basic diameter changes, and what the effect will be.

Something to remember, when the difference in diameter is shown as a percentage, you can go straight to how far off will the speedo/odometer be. For example, if the diameter is 6% bigger on the new tires, the speedometer will read 6% slow, odometer will be 6% out as well. As long as all 4 wheels are the same size, the computer will not complain about changing tire size within reason. There is a limit however on how large you can go. I do not know what the limit is, or even how the computer can tell, but, have read reports where some have had issues with extremely large tires.