# Taller tires, 28" possible



## drag miata (Jan 13, 2009)

Hello,
I am not a crazy. I am still searching for the perfect 04-06 GTO to buy but am contemplating the wheel issue. I have been using the search function looking for history on 18"-20" wheels.

Bigger wheels give a harsher ride for two reasons that they weight more so the suspension is not capable of recovering road contact as quickly. Secondly, there is less sidewall on the tire to cushion the impacts. Stock tires are 26" tall or something close to that. On a 17" wheels (26-17)/2 you have 4.5" of rubber to cushion the blow. On 18" wheels (26-18)/2 you have 4" or rubber which is 11% less that the 17".

Take the same math to a typical 19" wheel (26-19)/2 and you get 3.5". My logic is that on a 28" tire the math becomes (28-19)/2 which is back to a stock level 4.5" of cushioning.

My real question on this topic is "Is there anything in the rear wheel area to prevent the use of a 28" tire". I would still plan on using a staggered smaller front rim with a 26-27" tire up front where I believe that would be more fitment issues. If there is an issue, is it on top of the tire, behind the tire or the opening in the rear quarter panel.

Because I do not have a car yet to throw on a lift and stare at, has anyone gone this route or thought about it. There are some decent 19" wheels in the 16 pound range, and 20" wheels in the 20 pound range, I believe the stock OEM wheels are 26-28 pounds. These would minimize the rebound and suspension issues if fitment could be overcome.

Last issue is with a 28" rear tire gearing would be reduced by ~7.5% so fuel economy would go up similarly. From 16/26 to 17/28.....it would have an impact, numbers would be debatable but that is another subject altogether. But this logic helped my 2000 Vette to get 38MPG highway.

I know flame away.....just trying to get a discussion going.


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## thebassbass (Feb 4, 2009)

i run a 28" tall tire out back and so do alot of other drag racing guys you just might need bags, springs or something out back to hold the rear off the tires. and it will put your speedo off


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## drag miata (Jan 13, 2009)

Cool, I thought it wouldn't be an issue. I wouldn't mind shaping the metal inside the wheel well but do not like the idea of rolling the painted areas until I see a good example of this type of work being done.


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