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I know its a debated topic, 275's on stock 19" sport wheels...but i can pick up a pair of new 275/30/19 for real cheap and i'm in need of two tires. From what i've seen, most that run the 275 on the stock wheels run 35's...would running a 30 be an issue? would it buldge more? Not real sure how tires work exactly. Thanks!
 

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The second measurement is for the height of the tire. Going from a 35 to a 30 is a shorter sidewall so your speedometer will read approximately 3.8% slower. (Going 60 - reads 57.7)

Check this site for more tire sizing info: http://www.rimsntires.com/specs.jsp
 

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The second measurement is for the height of the tire. Going from a 35 to a 30 is basically 5 mm shorter radius (10 mm diameter) so your speedometer will read approximately 3.8% slower. (Going 60 - reads 57.7)

Check this site for more tire sizing info: http://www.rimsntires.com/specs.jsp
Thanks for the response. That makes sense, so other then the speedo being a little off, do you think there would be any issues with running them? I'll check the site out, thanks again
 

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I'm no tire expert and I've only owned my G8 for one day now. I don't want to tell you yes since I can't guarantee it but I would think they should fit since they're slightly smaller than the original. If they were slightly larger then you might get rubbing issues but smaller SHOULD be fine. Once again though, I'm not an expert or even experienced on this platform...
 

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The second measurement is for the height of the tire. Going from a 35 to a 30 is a shorter sidewall so your speedometer will read approximately 3.8% slower. (Going 60 - reads 57.7)

Check this site for more tire sizing info: http://www.rimsntires.com/specs.jsp

Maybe cause its late, this doesnt sound right to me.... if you move to a smaller tire, your speed wont read lower..... it will read higher... smaller tires need to rotate faster than larger ones... so in your statement if your going 60mph, your speed would read higher..... is this correct?.... or is it really late and I am not thinking properly??
 

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The second measurement is for the height of the tire. Going from a 35 to a 30 is a shorter sidewall so your speedometer will read approximately 3.8% slower. (Going 60 - reads 57.7)

Check this site for more tire sizing info: http://www.rimsntires.com/specs.jsp

you meant to say going to a smaller tire would..... (speedometer reads 60, your going 57.7)
 

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you meant to say going to a smaller tire would..... (speedometer reads 60, your going 57.7)
Yep, speedo will read faster than you are actually travelling. Which also means your odometer will clock more miles than you have actually put on the car.

The other thing to consider is your ABS system may stop functioning. There is a 4.4% difference between the original size tire, which I assume you still have on the front, and the size you are considering. The general rule is, don't go more than 2% smaller or 3% taller. Having 4.4% different heights front to back will probably throw some warning lights, not to mention it may look a little goofy with the smaller tires in back.
 
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