Taller Tires, Pros And Cons

grizzlyrafting · May 3, 2011

Hey guys,

Have a 100% stock '06 Sierra Z71 and want to get a little more height without having to spend big money on a lift and was wondering if I decide to go with a taller tire what are the pros and cons? How tall can I go? will if greatly affect driving conditions, speedometer, gas mileage? I appreciate all of your responses, Thank you in advance..

kdixer · May 3, 2011

It will effect mpg, power, braking and handling all for the worse. How much depends on how much taller you go. You can go a couple of sizes taller without serious issues. But it will negatively effect the things previously mentioned. But the effects are still tollerable.

mhenshaw · May 3, 2011

Hey guys,

Have a 100% stock '06 Sierra Z71 and want to get a little more height without having to spend big money on a lift and was wondering if I decide to go with a taller tire what are the pros and cons? How tall can I go? will if greatly affect driving conditions, speedometer, gas mileage? I appreciate all of your responses, Thank you in advance..

Pros - Looks, less mileage on the truck if you don't adjust the computer

Cons - heavier tires, less braking, less mpg

You should have no problem clearing 285s. Use this Tire size calculator for speedometer and tire sizes.

svaneld · May 3, 2011

I went with 285's on my 05 and have had 0 issues besides the obvious that have already been mentioned. My speedo is off right around 2 mph, low. I then leveled my truck by adding different keys on the torsion bars. This is a cheap way to get a good look. Had it alligned and have been loving it. Tires are wearing evenly I dont have any rubbing or anything like that. I did not notice a huge loss in power my biggest difference has been in MPG.

cghbuilder86 · May 3, 2011

MPG is the only reason I run stock size.

asc08 · May 3, 2011

Out of curiosity, is the mpg difference because of the larger tires putting more load on the engine, or the fact that the odometer will read lower (if it isn't re-calibrated), showing fewer miles per fill up? Or is it a combination of the two?

mhenshaw · May 3, 2011

Out of curiosity, is the mpg difference because of the larger tires putting more load on the engine, or the fact that the odometer will read lower (if it isn't re-calibrated), showing fewer miles per fill up? Or is it a combination of the two?

Both. Less mileage and added weight of tires.

Stock tires 265/70/17 and most common larger size 285/70/17

If you average 70 mph on a 5 hour trip. 350 miles/22 gallons = 15.9 MPG

Actually you would be going 72.44 mph for 5 hours. 362.2 miles/22 gallons = 16.46 MPG

CanadianT/A · May 4, 2011

I went with 285's on my 05 and have had 0 issues besides the obvious that have already been mentioned. My speedo is off right around 2 mph, low. I then leveled my truck by adding different keys on the torsion bars. This is a cheap way to get a good look. Had it alligned and have been loving it. Tires are wearing evenly I dont have any rubbing or anything like that. I did not notice a huge loss in power my biggest difference has been in MPG.

Same, put 50k on mine until I sold it with 285's

scottmoyer · May 6, 2011

I cranked my bars and put 285/70-17s on at 35k miles. I noticed about a 1.5 to 2 mpg loss with that change. I never use the DIC to calculate, because mine is always low by a gallon or more of gasoline used. I fill up with 21 gallons and it might say I used 18.7. I did make my changes at the same time our wonderful government mandated 10% ethanol, so that contributed to my mileage loss also. I haven't noticed any braking differences though. I traveled empty from MN to FL last year and ran about 70-75 (speedo has been re calibrated with Black Bear) and I was getting around 18 with the AC on