2004 Sierra Z71 Tires

[billykiller05]

I am looking for a new set of tires for my 2004 Sierra Ext. Cab Z71. I currently have 265/75/16's and am looking to increase to 285/75/16. I was needing to know if these tires will fit without any modifications?

 

[Deerassassin]

I have an 03 Z71 1500 4x4 and they fit. I trimmed maybe 1/2in off the front bumper. You can't tell I did.

 

[Z15]

Bigger and wider tires will affect fuel mileage. Bigger tire weigh more, have more surface area and more rolling resistance. Also, the truck is programed for the tire size you have and going to a larger tire will make the engine operate outside its designed torque range and could cause the transmission to shift differently and the speedometer to register incorrectly and all that could lead to less mpg.

DISCUSSION
The installation of oversize tires had the most profound effect on changes to rollover propensity and increased pedal forces for achieving equivalent levels of deceleration with oversize tires. Similar results were found when a series of straight-line braking tests sponsored by NHTSA were conducted to study the dynamic response properties of a modified light-duty truck, heavy-duty truck and sport-utility vehicle equipped with body/suspension lift kits and oversize tires. The reduction in braking performance of the test vehicle was primarily due to the installation of oversize tires and not the body and suspension lift kits. A 10-year research and investigation of crashes of modified vehicles by the Virginia Commonwealth University Crash Investigation Team concluded that oversize tires were likely the single most dangerous modification to “high-rise” vehicles.

http://www.aamva.org/aamva/DocumentDisplay.aspx?id={F8E41755-938C-4CCC-98B9-136C78F76797}