Hi all, I have a quick tire size question. For the past 5 years I've been running a set of original re-treaded bias-ply Firestone tires on my 1956 Pontiac Star Chief. They have served me well up until today when the tread finally blew out on one of the tires. So now it's finally time to upgrade to a set of Radials, but I'm kind of scratching my head as to what size tires to order. The Firestones are so old, all the say on them is 'Firestone Deluxe Champion 8.20-15 tubeless tires gum-dipped". So all I know is that I seem to have a 15" wheel, and not much else. Can anyone help me figure out what size radial I should be getting? And give some recommendations on what type/brand that is a good deal? I don't have a whole lot of money to spend, but at the same time I don't want to get complete crap. My only requirement is that I want wide (2" +) Radial White Walls. Other than that, I don't care about brand or anything else, and hopefully something that is cheaper than Cokers! Thanks all in advance!
Thanks, I'm guessing 215/75-15 or 225/75-15 might fit? I can't find anything locally that might work, I guess I'll have to check Diamonback or Coker and drop a grand...
I'm running a 215/75-15 on my 62 Pontiac Bonneville wagon... They look really good, and fill the wheel well perfect.... I think a 215/75 would be a good choice.. just my 2 cents.. In the end it's up to you and what you like...
Those 8.20's must really fill the rear wheel well! Do you have fender skirts on it?If so do the brackets rub on the tires? Normal tire size on them was 7.10 and 7.60 was optional. My Safari has 215/75-R15's all around and I get some minimal tire scrape on the skirt brackets on a hard corner or have a load in the rear and forget to inflate the air shocks.
It will probably be difficult to find white whitewalls locally, for those you'll have to go to Diamondback or Coker. Narrow whitewalls or blackwalls will be easy, you can buy them at any local tire store. Some people can grind the sidewalls on modern tires to make the whitewalls wider; I don't have experience with that, but you can probably find more information here with a search. Per the Coker website an 8.20-15 has a diameter of about 29.59", based in information from the Tire Rack website the closest modern size would probably be a 235/75R15 which is about 28.9" diameter (there will be slight variations from one brand to the next.) edit: as others have posted, the 8.20s are probably oversize from what was original on that car. edit x 2: The Old Car Brochure website has a fact book for the 1956 Pontiac, it says standard tire size was 7.10-15 with 7.60-15 optional. A 7.60 tire has a diameter of about 28.66" which is closer to a modern 225/75R15. The Pontiac Fact book is here: http://www.oldcarbrochures.com/static/NA/Pontiac/1956_Pontiac/dirindex.html
Thank you guys for the help. You are absolutely right the 8.20's are wayyyyy oversized. i want to go back to a normal sized tire for the car. They do just barely rub at full turn and when loaded down. I don't have fender skirts on, and even without them I could barely get the tires to fit. I just got these Firestone original 50's retreads from a guy off Craigslist up in Oregon who had them sitting in his auto repair shop since they were originally retreaded in the 50s! I paid $200 shipped for all 4 of them since I was on a tight budget with my restoration at the time, and they have lasted well for 6 years and thousands of miles. However now that my front end suspension is rebuilt, I really need some radials to make the car ride and steer right, and I would really like to go back to a normal size tire. These look a little goofy being too big, so I guess the consensus seems to be about a 225 or 215 / 75 15. I'll start looking at my options via Coker and Diamonback and see what I can afford. Thanks again for the help determining the right size...as usual that HAMB always has the info I'm looking for! CASE CLOSED
I'm chimming in a little late but I just went thru the exact scenario on my 56 Pontiac 4 door hardtop. I had 225/75 R15 s and not only did they look alittle too big but also getting the tires in and out of the rear wheel wells was difficult. Even jacking the car up under the frame to let the rear axle drop, the tires still rubbed trying to stuff them under the quarters. That's without skirts. I bought a set of 215/75 R15 from Diamond Back and they look perfect and do not rub when sliding them under the rear.
Thanks rare, I ended up using a 225/75 from Coker. I looked into get the 215 also, but since I have 3" lowering blocks on the leaf springs in the back, I knew I wasn't going to be able to get any size tire in without the axle being dropped down or the car up on a lift. So I went with the slightly larger tire and they turned out great. Coker had a better price over Diamonback, and although I'm sure they are both quality tires, I went with Coker. Now that the tires are on the car, I'm extremely happy with my new radials.
hahaha great reaction! You are right, I am lucky it wasn't a bad situation! I was on the freeway but was in the slow lane since I don't like driving that car over 60 due to the drum brakes. It started riding really rough and vibrating a lot, which I recognized what was about to happen because the same thing happened on my truck when I wore down a set of tires and blew one on the freeway, ripping off the rear fender of the truck. So I played it smart and pulled over and called AAA before the tire actually exploded. The tread was shredded, and there was a huge bulge in the tire, but it hadn't actually exploded yet. And yes, the car looks AMAZING with a nice set of tires on it. I'll post a few pics soon.
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