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Tires/different tire size between front and rear


I have a 2005 Cadillac SRX V6 3.6 DELUXE EQUIPMENT, AND SPECS ASK FOR 235 60 R18 on the front and 255 55 r18 at rear , can I put the four tires of same size??? (235 60 r18)  I choose the front ones because the rear ones are wider and could be heavier for the front suspension, also I want to do the normal rotation on all my car tires


It took a bit of digging, but the best information I have is that the rear tires have a larger load carrying capacity - and I think that means you will have to use a higher inflation pressure if you decide to use the same size as the front tires - +4 psi compared to the fronts.

Other than that, I see no reason not to go there.  Just be aware that some tire shops may not want to deviate from what is on the vehicle tire placard.  You may have to shop around to find one who will.


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Barry Smith


I have over 30 years experience in the design, manufacturing, and testing of tires. I have served as the technical advisor to the "800" number. I have authored or co-authored many publications - usually without credit. I can answer almost any technical question, but please don`t ask me to compare brands. I probably have prejudices because of my work experience.


Member SAE (Society of Automotive Engineers) Member Tire Society (Tire Technical Organization) SCCA Regional Competiton License holder Authored many training manuals on tires, their care and use.

SAE (Society of Automotive Engineers) SCCA (Sports Car Club of America) Tire Society

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I am a graduate of the University of Dayton, Dayton, OH - BME, 1971 I attended graduate school at the University of Akron - but did not complete my PhD - something I regret.

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