Hey everyone, I was wondering if anyone has tried fitting 275/40/18s on the stock 18 inch bullit wheels, which are 8.5 inches wide. Tirerack says the minimum requirement for such a size is a 8.5 inch wheel. For some reason I'm skeptical. Im lookin to buy some Black bullits like the ones that come on the stangs. I wanna throw some 275s on the rear but i'm not sure if it would be safe. Anybody have any experience with this matter?
Thanks.
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05' Mustang GT K&N 63 series intake Flowmaster Axlebacks Back to factory tune for now.....
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Joined: 5/21/2005 From: S.burbs Chicago Status: offline
Somewhere someone on here has 285/40/18 stuffed on the stock 8.5" It didn't look all that bad. Hard cornering will be effected by more sidewall flex, just keep that in mind.
Somewhere someone on here has 285/40/18 stuffed on the stock 8.5" It didn't look all that bad. Hard cornering will be effected by more sidewall flex, just keep that in mind.
I saved the pic on my home pc, at work now.
Yes i'm aware of the cornering performance tradeoff. However, last time I checked, a straight was the only thing I cared about . So you don't think it would be a problem to put 275s on 8.5in wheels?
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05' Mustang GT K&N 63 series intake Flowmaster Axlebacks Back to factory tune for now.....
You can make it fit. But it will tend to run a little hotter because the sidewalls will flex a little more, and the 'flex point' isn't in quite the same place that the tire design was based on. IOW, it's definitely not the hot tip for long high speed drives or carrying heavy loads in hot weather (pun not really intended). Performance-wise, I suspect that you'd actually get better acceleration traction if you moved up to rims equal to the "measuring" width.
Note that not all tire mfrs will list 8.5 as being acceptable for 275/40's. Make sure that it's OK for your specific tire make/model.
Norm
< Message edited by Norm Peterson -- 1/16/2008 9:49:57 AM >
Ya i've heard that actually. The fact that the sidewall will be affected negatively. But hey, if that guy put 285s on the same wheels, I can surely get away with 275s.
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05' Mustang GT K&N 63 series intake Flowmaster Axlebacks Back to factory tune for now.....
But hey, if that guy put 285s on the same wheels, I can surely get away with 275s.
That is perhaps the single scariest thing about these tire and wheel threads - the way any number of readers will eventually interpret posts that publicize the use of irresponsible combinations. You happen to be one of the 'known' readers. Who knows how many others have taken (or will take) that same posted information and simply run off to their tire store with it? Or worse, take an "it's only another 10mm wider" approach and go with a combination that's even further out of spec?
The worst of these postings do not include specific reasoning for the choice (normally it's only an appearance issue) and disclaimers about it not being generally the thing to do, etc., etc. But it's really an engineering thing, and the unfortunate reality is that very few people look at it that way (a long time ago at about age 20 I didn't, either). Granted, there actually are a couple of situations involving very short-term use where going below the tire mfr recommended rim width range can be defended and considered acceptable for such short durations only. Long-term use in general street/highway driving . . . can't be.
I've posted elsewhere that being only half an inch below spec (8.5" vs 9") isn't going to guarantee that you will have a failure or other unpleasantness. But it does represent giving away some of the margin of safety that is intended. An inch below spec gives away more (perhaps a lot more). Simply put, the line between 'acceptable' and 'not acceptable' has to be drawn somewhere.
Yes, that does mean that you'd be better off with the 275's than that other guy is with the 285's. But please understand that it's false logic to make comparisons against a combination that is "iffy" at best when legitimate data is only a couple of mouse clicks away at places like the TireRack site.
Sorry if this sounded like a rant.
Edited to fit without having to scroll R/L
Norm
< Message edited by Norm Peterson -- 1/18/2008 5:18:25 AM >
But hey, if that guy put 285s on the same wheels, I can surely get away with 275s.
That is perhaps the single scariest thing about these tire and wheel threads - the way any number of readers will eventually interpret posts that publicize the use of irresponsible combinations. You happen to be one of the 'known' readers. Who knows how many others have taken (or will take) that same posted information and simply run off to their tire store with it? Or worse, take an "it's only another 10mm wider" approach and go with a combination that's even further out of spec?
The worst of these postings do not include specific reasoning for the choice (normally it's only an appearance issue) and disclaimers about it not being generally the thing to do, etc., etc. But it's really an engineering thing, and the unfortunate reality is that very few people look at it that way (a long time ago at about age 20 I didn't, either). Granted, there actually are a couple of situations involving very short-term use where going below the tire mfr recommended rim width range can be defended and considered acceptable for such short durations only. Long-term use in general street/highway driving . . . can't be.
I've posted elsewhere that being only half an inch below spec (8.5" vs 9") isn't going to guarantee that you will have a failure or other unpleasantness. But it does represent giving away some of the margin of safety that is intended. An inch below spec gives away more (perhaps a lot more). Simply put, the line between 'acceptable' and 'not acceptable' has to be drawn somewhere.
Yes, that does mean that you'd be better off with the 275's than that other guy is with the 285's. But please understand that it's false logic to make comparisons against a combination that is "iffy" at best when legitimate data is only a couple of mouse clicks away at places like the TireRack site.
Sorry if this sounded like a rant.
Edited to fit without having to scroll R/L
Norm
Yes I agree with you. I'm not an idiot. I'm not going to base my decision on what members have posted on the forum. I will, however, take such things into consideration. According to tirerack.com the maximum width of a tire on an 8.5 inch rim is 275. Could that be wrong? I dunno. I'm going to continue looking into it.
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05' Mustang GT K&N 63 series intake Flowmaster Axlebacks Back to factory tune for now.....
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275s on 8.5 inch wheel? - 
. So you don't think it would be a problem to put 275s on 8.5in wheels? 
