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Discussion Starter #1
vs. 245/40 19

Pro:
-More sidewall.
-More fuel economy...possibly.
-Fills more space in the wheel well.
-Nice selection of tires at that size

Con:
-Larger diameter could screw with cars electronics, but I'm not sure if that increase would matter.
-Possible rubbing, but I'm not planning on lowering too much. Maybe Tanabe springs.

I would like some feedback, because I don't see that size being talked about.
 

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I'd shy away from that size, since it's outside the 2-3% difference in diameter that's usually within tolerance for different tire sizes (3.6% actually).

If you're looking for a taller sidewall, have you considered maybe a 235/45-19? That size is within tolerances...
 

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You have to keep the overall diametre within 3%
 

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Discussion Starter #4 (Edited)
Thanks, I figured if it would work, it would have been a size that was discussed more. 235/45 19s would be great, but it seems like there is a very small tire selection in that size. At least at Tire Rack.

EDIT: how are you guys calculating the % difference?

I took the overall diameter of larger tire and divided by stock tire

27.0 for 225/45 19
27.7 for 245/45 19

27.7/27.0 = 1.026, which is a 2.6% difference.

I even compared the revs per mile.

770 for 225/45 19
751 for 245/45 19

751/770 = .975, which is a 2.5% difference.

so that seems like it shoudl be ok, unless that difference is calculated some other way.
 

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Discussion Starter #7
cool, thanks for the links!

I tried both, and they both say the difference is what I calculated, which is less than a 3% difference.
 

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245/45/19 if your stock height
245/40/19 (I have) if your lowered.

Works perfectly for me.
 

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My sincerest apologies. I compared the 245/45 to the 245/40 in your OP.

Rechecking the numbers gets me the 2.6%...

In that case, go for it! :D
 

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BTW Tirerack is selling Pirelli PZero Silvers 245/45 R19s at half price ($150 instead of $300) in closeout. I'd get those in a heartbeat if I was in for tires right now. They are the only 23lb summer tire I've found in that size. Everything else is 24-30lbs.
 

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Discussion Starter #14
Is it possible to install 245/45-19 on the factory 19" rims?
I'm sure it's possible, but I was looking at wider wheels that the factory ones, and wheel width can affect the overall diameter. With a wider wheel, the diameter will be a bit lower than with a narrower wheel.
 

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Discussion Starter #16 (Edited)
Yes, from 225/45 19 to 245/45 19, the diameter gets bigger.

But if you put 245/45 19s on a 7.5" width wheel, vs. a 8.5" width wheel, what then? It is my understanding that wheel width can affect diameter because of how the wheel affects the tire.

Take a donut and put it between your hands. Now squish the donut. The diameter gets bigger.

The difference in diameter between 225/45 19 and 245/45 19 is already close to 3%. A 7.5" wide wheel is on the narrow side for 245/45 tire, and I suspect that the squish to get it to fit will increase the diameter a bit over what it would be on a 8.5" wheel. I don't know if this is actually significant, but I figure I'd point it out if that's a factor for him.

Because I am interested in a 8.5" wide wheel, I think sticking with 225/45s is more stretch than I want. 235/45 19s would be ideal, but its a size with very few tire options. I don't want to do 245/40 19s because they are shorter than stock and I want the extra sidewall here in NY. The 245/45s also fill in more of the wheel arch, which I think is better visually. Also, there are lots of tires in that size, and it makes shopping for tires much easier/cheaper.

Sorry if I wasn't clear before.

EDIT: So I looked it up, and it seems that this is not really true on steel belted radials.
 

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Hi Guys,

I'm really new here, in fact i just registered on this forum. I was browsing through the various threads and found this, which seems to be the most suitable one so far...

This is a little off-topic, cos my wheel/tyre size is abit different. i'm moving up from the stock 17" wheels to an 18" size.

my current setup for wheels/tyres is 225/55/17, and im thinking of getting Eagle F1 As-2s in 235/45/18. Other than the concerns in diameter, will there be any concern regarding rubbing of the fender / strut of the car? i hear goodyears tend to have thicker sidewalls and hence am a little concerned.

I would really appreciate any advice on this.

Thanks!
 

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Discussion Starter #18
well, your overall diameter is a bit lower, but not by much. The tires will be a bit wider. I don't imagine that you would have any issues unless your 18" wheels have a really high offset. But I have no personal experience. People here are running much wider tires.
 

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235/45R18 is factor size on Gen 2 wheels with 18s, should be fine
 

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Oh yes, i totally forgot.

the offset for the new wheels is +45 vs the factory of +50.

Im not sure too, because when i went to a car workshop, the person who attended to me was the one who pointed out the potential issue of rubbing. and since the tyres cost upwards of $310/pc here, i don't want to order them and later find out that they cannot fit. haha..

thanks for the advice!
 
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