getting 92 Z28 back up and Running. need a fresh set of ET Streets.. right now i have 28 12.5 x15 fit fantastic! thinking about 30 12.5 x15 any body bolted a set on this size..? looks like they will fit.. just wana ask first.. today is the first time the car has been washed in 6 years.. will get the photos up.

The width of a slick is measured across the tread. The width of a DOT tire such as an ET Street is measured across the section width. Using MT tires for sizes...

Your 28x12.5 ET street has a 10" tread and a section width of 12.6"

A 28x9 slick has a tread width of 8.5" and a section width of 11"

A 28x10.5 slick has 10" tread and 11.7" section width. This would be very close to your ET street tires.

A 28x10.5W has 10.9" tread and 13.1" section width. Depending how close your ET Street tires are, this may be the limits to what you could use without doing sheetmetal work.

I was able to squeeze a 29.5 x 10.5 slick under my fenders but it requires a bunch of inner fender modifications to allow the taller tire to fit under the fenders. My car is now back halved and I run a 32x14 slick

If you want a DOT tire, you can easily use the MT web site to see the dimensions of the different tires. Since you know how much clearance you have around the 28x12.5's, you can get a rough idea how much more you can go. Going much wider than that and you may need wider rims. The narrower tires work well with an 8" rim but going to a 10"+ wide tread should use a 10" wide rim. You never stated current rim size or backspacing.

this is why it's good to ask...

i was thinking that the 30 12.5 x15 was just 2 " taller
the the 28 12.5 X15.

both are ET STREETS.

The Sec width is 1.20 wider. the rest is the same... could use a 2" taller tire for the top end..untill i look closer ill stick with the 28x12.5x15


$340 for the set 28 12.5 x15 ET Streets then 10% off sale
$330 after tax beat that summit... (shop 4 blocks from my house)

The taller tire has clearance issues especially at the front inside inner fenders.

better question is...why?

thats why im just sticking with the 28" tall.. i know it works..

same price sale...

a 28" slick can put you into the mid 8's with ease. i wouldnt go bigger unless you want to go faster than that, or you are wanting to bracket race.

Hey AlchyIROC, I am ordering slicks this week for my 86 z with a 540ci BBC it had 28x10.5x15 MT slicks and would like to go to a taller GoodYear Slick either a 30.10.5x15 or that 29.5x10.5x15 slick I need the taller tire for when I spray it. I see that you had the 29.5's on yours just wondering what exactly you had to cut on the inner fenderwells? I have spent countless hours beating the hell out of them and the 28's fit nicely. Thanks Dave

A search through the forum archive pulls up this thread. There are many more just like it.

http://www.thirdgen.org/techboard/su...-rim-back.html (10" wide rim on the back)

Im running 8.60's with a 28x10.5W.

i have a 15x10 wheel with 6.5" backspace