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Tire Size Question

Hey guys,

I was wondering how wide of a tire we can fit on our G6's without rubbing. I have 225/50/17 on my coupe, and I'd like to go a bit wider, but I'm not sure how wide to go before rubbing. Thanks
 

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225/50r17 ----> 215/55r17 question?

Switching out my All Seasons for winter tires, I purchased the 215/55/r17 snow tires as suggested by Tirerack as a alternative to my 225/50/r17s. When I got them installed I was told that it would ruin my transmission. I have a feeling they were just flubbing on me but thought I would check here. Will I have any problems with this replacement?
 

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Not sure how that can ruin your transmission.....

It will probably affect your speedometer though. Since you changed from a 50 to a 55 sidewall ratio. You will be going slightly faster then your speedometer will be reading.
 

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Thanks as expected. This is a GM dealership too. She didn't seem to know what she was talking about. But they noted the tire change on the receipt. Just received a email from Tirerack saying they were full of it also. :D
 

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well being u went from a 225/50 ( 50% of 225 for your sidewall height ) to 215/55 ( 55% of 215 for sidewall it should only be a mile or so off on your speedo ...

Specification Sidewall Radius Diameter Circumference Revs/Mile Difference
225/50-17 4.4in 12.9in 25.9in 81.2in 780 0.0%
215/55-17 4.7in 13.2in 26.3in 82.7in 767 1.8%

wont hurt the tranny ...
 

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Yeah, the stealerships will tell you that your muffler bearing is the first thing to go if you fail to let them screw you on a regular basis.
I hardly believe that a 1/4" taller or 3/8" narrower tire will do anything to anyone's car.
 

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I run Firestone Winterforce tires in the 215 55 R17 size and have had absolutely no problems with them.

They cost almost $50 less per tire than the 225 50 R17's that came with the car.

Winter grip is actually improved because the aspect of these tires is slightly taller and skinnier. On snow and Ice, skinny tires are better because they can cut through the snow to pavement better than wide ones. There is a lot of science to it, but the quick explanation is that the weight of the car is focused onto a skinnier and longer pattern which keeps rubber in better contact through water, snow, and slush.:D

Enjoy your new tires, they won't cause your transmission to do anything but transfer power from your engine to the ground. (which is remarkable actually considering that is what its supposed to do)
 

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widest tire on a 18X9 rim

im getting a 2008 g6 gt and i have some boss 18X9 rims i want to put on it and i want to know whats the widest tire i can go on them, i want them all the same so i can rotate them...thankz guys
 

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i'm not sure what the widest you can go. i do know the Pontiac used an odd size which limits what you can use. i just got my 07 gtp and it was in NEED of tires, so i just bought 16" steel wheels and snows. i have found the 225/50's that are stock is a limiting size. going to a 235/45 will open up more and better choices, but speed and mileage will be just off a little.

With that being said, what tire's are recomanded by everyone eles?
 

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Wheel Width Question

will a 19x8 fit on a 08 g6 gt with out any clearence/rubbing issue. and also will they clear with eibach sportlines
 

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I would like to get a little debate going on here about tire size for a 17" chrome rim for the G6. Stock when I purchased the car had Hankook optima's that were 225 50 R17. I heard a lot of people going to the 215 50 R17, but no one going to the 235 50 R17. Also I got 46k out of my first set of tires

I always believe the wider tire is better for ride and comfort and handling, just not good for gas mpg's. So, I went ahead and got Yokohama Avid ENVigors at 235 50 R17. I also did a suspension/brake upgrade as well, but that's another topic. I have had them on for about 700miles so far, and the mpg avg is down from 24.9 to 23.4. BUT, the ride is phenomenal with the wider tires! You hear less, have more grip, and its actually a little faster, taking up more space on the ground, and better in snow.

The myth that different size tires will ruin your tranny are false, unless you have 1-2 different siezed tires on there from the others. If you have uniformly the same size, you are fine. Auto Dealers are THIEVES.

But I would like some feedback to see what other G6 owners purchased.
My car is an 08 GT 3.5L
 

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If you change your tire size you need to keep the same overall tire diameter or your speedo will be off, unless you have your computer programmed to allow for the different size. You have gone to a small diameter, so your wheels are spinning faster. Also, the wider tire will not do better in the snow because of the pressure per square inch is less with wider tires. So if you incease the first number (measurement from one bead to the other including sidewall and tread) then you also have to go with a different aspect ratio (the center number of the tire size). You are correct that to cause damage to your driveline you have to have different sized tires on the same axle or if awd just different sizes anywhere can cause issues. Those who are changing from 225/50/17 to 215/50/17 are getting taller tires, and also may not have the same load rating so could be creating a safety issue. Their speedo is going to say they are going slower, but are getting better rain and snow traction. Basicly if you are putting on a wider tire, then the aspect ratio needs to be less than the original, if going narrow then the aspect ratio needs to be greater.
 

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will a 19x8 fit on a 08 g6 gt with out any clearence/rubbing issue. and also will they clear with eibach sportlines
those should fit even with a lowering kit; however, I am just assuming. I have 20x8.5 with a 225-35-30 tire and I still have a lot of room to play with. I know someone who has 245-35-20 which are taller but they do rub some on deep turns. I would so go for it. 19 inch rims lowered would look sweet!
 

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Those who are changing from 225/50/17 to 215/50/17 are getting taller tires.


Basicly if you are putting on a wider tire, then the aspect ratio needs to be less than the original, if going narrow then the aspect ratio needs to be greater.
that first part is wrong, 215/50/17 is a smaller tire than 225/50/17 im guessing you meant to put 235/50 in there? as you got the 2nd part correct LOL
 

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I would like to get a little debate going on here about tire size for a 17" chrome rim for the G6. Stock when I purchased the car had Hankook optima's that were 225 50 R17. I heard a lot of people going to the 215 50 R17, but no one going to the 235 50 R17. Also I got 46k out of my first set of tires

I always believe the wider tire is better for ride and comfort and handling, just not good for gas mpg's. So, I went ahead and got Yokohama Avid ENVigors at 235 50 R17. I also did a suspension/brake upgrade as well, but that's another topic. I have had them on for about 700miles so far, and the mpg avg is down from 24.9 to 23.4. BUT, the ride is phenomenal with the wider tires! You hear less, have more grip, and its actually a little faster, taking up more space on the ground, and better in snow.

The myth that different size tires will ruin your tranny are false, unless you have 1-2 different siezed tires on there from the others. If you have uniformly the same size, you are fine. Auto Dealers are THIEVES.

But I would like some feedback to see what other G6 owners purchased.
My car is an 08 GT 3.5L
I ride the 235 on my G6. I forgot the verticle size but I know it the step up in height. Yes lower fuel economey and lower handling but a noticable difference in the ride, much smoother.
I did it for the look, I like the wider profile of the 235 tire vs. the 225. To me it fills the gap in the fenderwell and any fill there, IMO, is a good fill.:D
 
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