Why are so many people 'upgrading' from 19x9 to 19x8.5?
10-13-2008, 03:43 PM
#12
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I haven't noticed any detriment to handling, but I changed several variables along with the wheels
1) switched to different tires (PS2 vs. Pirelli PZero Rosso)
2) added 20mm spacers (factoring the higher offset of the new wheels, the net result was an increase in track by about 24mm total, front and rear).
3) and then of course the lighter wheel itself, with the inherent benefits on handling and whp.
so, as an isolated variable, I can't comment on the effect of reducing wheel width by 0.5"...too many confounding variables...but the rim is well within spec for that tire size. obviously, if you wanted to go with a wider tire (265 or 275, as many have done) that probably wouldn't work well with an 8.5" wide wheel.
2) added 20mm spacers (factoring the higher offset of the new wheels, the net result was an increase in track by about 24mm total, front and rear).
3) and then of course the lighter wheel itself, with the inherent benefits on handling and whp.
so, as an isolated variable, I can't comment on the effect of reducing wheel width by 0.5"...too many confounding variables...but the rim is well within spec for that tire size. obviously, if you wanted to go with a wider tire (265 or 275, as many have done) that probably wouldn't work well with an 8.5" wide wheel.
10-13-2008, 09:30 PM
#15
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So why would Audi use a 255 profile on the OEM 19s?
Cost works against them, and as it were, the PS2s that we get are the High Load version, which makes them even more expensive.
10-14-2008, 08:03 AM
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speed, turning, friction, weight to name a few
you have enough grip with the std tire size and AWD. If all you want to do is lumber around without ever losing any grip, then go for the widest tire out there.
10-14-2008, 12:05 PM
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Had dinner with a buddy in the wheel industry
And supplies racing wheels to Bahrain's International Ciruit, and works with race teams and leading wheel manufacturers
255 width tyres are the correct and ideal size for production cars on 9" wide rims based on the following calculation:
255 / 25.4 = 10.03"
The ideal rim width for production cars is 10% smaller than the width of the tire, therefore 10"-10% = 9"
For race cars, the ideal rim width is exactly the width of the tyre, therefore a 10" rim would be right.
Apparently, this is the formula used by leading tire and wheel manufacturers when advising and supplying wheels and rubbers to race teams and car manufacturers.
255 width tyres are the correct and ideal size for production cars on 9" wide rims based on the following calculation:
255 / 25.4 = 10.03"
The ideal rim width for production cars is 10% smaller than the width of the tire, therefore 10"-10% = 9"
For race cars, the ideal rim width is exactly the width of the tyre, therefore a 10" rim would be right.
Apparently, this is the formula used by leading tire and wheel manufacturers when advising and supplying wheels and rubbers to race teams and car manufacturers.
10-14-2008, 12:28 PM
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Oh, I'm not disputing that
I guess I'm looking at it from the standpoint of going bigger and bigger on wheel diameter and width, just to out do the other guy or the previous model. I'm talking about the car mfgrs here.
Same with engine size and HP. It gets to be counterproductive, and outright ridiculous in some cases. With the latest oil crisis, displacement and HP wars seem to have been rightfully shelved...with smaller turbo or SC engines coming back.
In the case of wheel and tires sizes, I don't see anything forcing sanity back into the picture. There are so many drawbacks to larger and larger wheels and tires that it's almost an epidemic. Steering and handling suffers alot, with the only quasi benefit being more grip...the perceived magic bullet. No thanks!
Same with engine size and HP. It gets to be counterproductive, and outright ridiculous in some cases. With the latest oil crisis, displacement and HP wars seem to have been rightfully shelved...with smaller turbo or SC engines coming back.
In the case of wheel and tires sizes, I don't see anything forcing sanity back into the picture. There are so many drawbacks to larger and larger wheels and tires that it's almost an epidemic. Steering and handling suffers alot, with the only quasi benefit being more grip...the perceived magic bullet. No thanks!