Gerry

I've recently purchased a 90 RS and it needs new tires. I'm looking at the current ones which are 215 x 65 x 15 which is a 26 inch tall tire.

I scrap my front ground effects on my driveway everytime I come and go, so I want a taller tire. A little fatter tire would be nice too.

Looking at the specs for the Firestone Firehawk SS20 the 275x60x15 is 28 inches. Just curious if anyone has a 28 inch tall tire on their 3rd gen with stock rims, springs etc without any clearance issues.

Thanks!!

Gerry-
Norfolk, VA
96 Impala SS
90 Camaro RS

DJ_951

Use to run a 225/60-16 on my IROC and would not rub but just fix. May want to measure and compare. 245/60-15 max width in frt I've heard of. Good Luck The tire thing is almost trial and error on off sizes.

IROCKER

You can run up to 255 on the front and 265 on the rear without a rubbing issue. This is my understanding.

DJ_951

I think that's on a 16" 50 series for 255????????

Gerry

My RS rims are 15's, so a 255x60 would be 27.1 and a 265x60 would be around 27.6 or so.

I don't think I want the hassle of having one size tire on the front and another size on the rear, although the Firestones are not directional, so I could still rotate side to side.

I guess tonight I'll have to look at the clearance. On Impala SS's the front clearance is pretty much limited by the steering stops but with too wide a tire it will rub on the front sway bar. The rears shouldn't be an issue I would think.

Anyone else with info, its appreciated!

-Gerry

irocz383

You can't rotate the front to the rear so why not go wider on the rears?

I'm running 245/50/16 on the front and 255/50/16 on the rear. No problems at all!

I've heard of people runnning 315's on these cars with some minor sheet metal work with a hammer and a bigger offset tire!

Gerry

On the RS I have 15 inch rims which are the same width, same offset. I suppose this is because of the rear drum brakes. I do understand that certain third gens with rear discs have a different offset on the rear and can't rotate front to back.

My concern is strictly tire clearance. I am probably going to go with a local Firestone dealer and their 255 x 60 x 15 Firehawk Indy series. 4, mounted/balanced/front end align for $422. Tire Rack has them 4 for $306 with shipping, but I figure it'll be about $60 install/balance then $60 for a front end alignment. I'll make out better local, plus see the guy face to face in case something doesn't fit right we can back off to something different.

I am leaning going to a little wider in the rear. The 275 x 60 x 15 is appealing, but its also one full inch taller.

Decisions/complications.... sheesh!

Keep the feedback coming though!

-Gerry

Chris`s85Z28

I just got P255/60R15 out back and P235/60R15 in front there Goodyear Eagle GT II and I love them no clearence problems at all

todd200

I have 275/ 65/ 15 on the rear and 225/65/15 on the front of my IROC. I haven't actually driven it yet, but I haven't seen any clearence problems or areas they could rub. BTW there is another guy in town who has the same size tires as mine on his IROC. The 275/60/15 you are thinking about are 5% shorter so you should have no problems.

z28redline

I got a friend that runs 255/60/R15 up front and 295/60/R15 in the back on his 84 Z28. He claims they only rub when he hits a good size bump. Personally though I would stick to 235/60/R15 all around.

Gerry

Well I'm going to try the 255 x 60 x 15's on the front tomorrow and see how they fit. If the dealer has 275's I might look at them but that tire is MIGHTY tall!

Maybe I just have tire size envy since my Impala has the 255 x 50 x 17's and they just never seem wide enough.

-gerry

Sciguyjim

It doesn't sound like you are concerned with how much changing the tire size will affect the speedometer, but just in case you're wondering, the site below lets you compare tire and wheel sizes and tells you how much difference there is between them:

http://www.miata.net/garage/tirecalc.html

It's a helpful site

rickyzZ28

I have 265-50-15 on all four wheels. No scraping at all. They will rub the frame if you cut the wheel all the way though. Also these are on Cragar Drag Stars and not the factory wheel.

IROC5.7TPI

Well I think we should look at this issue from a scientific standpoint.

Camaro's are sports cars that are made to ride low and handle well. Raising the car with taller tires will raise the center of gravity and negatively affect handling. Also realize that when most guys upgrade their tires they go from a 15" to a 16" and from a tall sidewall to a low profile sidewall to increase handling ability.

I don't want to come off as being cocky when I say this.... but if you want ground clearance you should buy a truck.

Gerry

Guys,

Understand the issues, and I still want that extra 1 inch. And its for ground clearance at the moment as well as filling up the wheel well. The car handles better than my Impala SS, and the Impala has the full Hotchkis setup and BMR control arms etc. But this little Camaro just HUGS the deck!! Cool!

The Camaro is also my daily driver, nothing more. ( at least at the moment... )

I can adjust for the larger tire size I believe. Don't know how
the 4L60 and RS compare to the later models, but either TunerCat or a different speedometer gear will do the trick. TunerCat has a new definition file for the 90RS V6. I've looked through it and didn't see a rear gear adjustment or tire size adjustment so I will assume right now its got to be done with a speedometer gear. I could be wrong.

We have a EEPROM burner in the Impala club here, and are setup to burn EEPROMS all day long. There are a couple of guys with 3rd gens and one with an 89 Vette and a supercharged L98. We've changed his chip several times.

Anyone certain about the speed/gear adjustments for the 90 ?

Thanks guys!