Question: I have recently purchased a 2011 Toyota 4Runner SR5. I want to upgrade the tire/wheel combo. I'm seeking a more off-road look. What's the largest size tire I can use without doing any modifications? I don't really do any hard-core off-roading; I just love the look. Any help would be greatly appreciated.
Answer: That's never been an easy question to answer. If you go to a tire website such as www.discounttire.com, you'll find a tire/wheel plus-sizing option. This gives wheel and tire matches to allow the use of larger-diameter wheels (say 17- to 20-inch) while reducing the sidewall height of the tire, thus maintaining the proper overall OEM wheel diameter. This eliminates changing the final drive ratio, in turn maintaining the vehicle's original performance characteristics, speedometer reading, and so on. This also eliminates any fender/frame clearance problems. In the process, a certain amount of increase in tire width is allowed. This does not cause clearance problems to the extent of increasing wheel diameter, but going too wide will inevitably make contact.
In your case, achieving an off-road look involves increasing wheel diameter (height) and most likely width, also. Some folks are willing to deal with (or ignore) the lesser performance off the line, and the incompatibility of the final drive ratio with the powertrain control module's software, but the body/frame clearance is still an issue. Without the installation of a suspension lift kit, you can go only so far past the OEM wheel diameter and width without making tire to body/frame contact on turns, or over dips in the road. I'm not going to give you wheel/tire sizes that might work, because the information wouldn't be reliable without testing. My suggestion would be to log on to some highly traveled 4Runner forums, and get input from folks with the same model 4Runner who have already gone through the hit-and-miss scenarios. This should help determine what sizes will work, and which won't.
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