RetroRanger

1972 cutlass supreme, just used for cruising.

I just checked the date code on my tires = 503. If I'm reading that right (pre 2000 date codes have only three digits) it translates to 50th week 1993 at the newest.

So even tho these tires only have 5 k ish miles on them and look good i.e. Not all cracked no bulges etc, I'm inclined to replace them.

I can get BFGs or Cooper Cobras in my size of choice 255-60-15s, but is there any value in going to a 17 or 18" rim/tire combo? A size like 255-45-18 is the same 27" tall as my current tire but is there any benefit to the increased rim size?

I would guess the lower profile tire would aid handling, but would the ride necessarily be rougher as a result?

Many modern cars run a 45-55 sidewall tire so I'm wondering if it's a good idea for older cars like ours?

cutlassjoe

I'm running 17" on my 72' on a torque thrust type rim. They look good and the car handles a bit better. The ride is a bit rougher but not too much. The rims look good and at first glance you don't notice they are 17".

joe_padavano

[QUOTE=RetroRanger;1096962 is there any benefit to the increased rim size?[/QUOTE]

Assuming all else is the same (same tread width, same tire OD) then the only difference is the shorter sidewall. Advantages are 1) less sidewall deflection so more precise handling, and 2) larger rim allows larger brakes. Disadvantages are 1) rougher ride, 2) more easily damaged rim on a pothole, and 3) forking out major bucks for new wheels. The aesthetics of big(ger) rims and "rubber band" tires are a personal taste issue.

anthonyP

Personally, I prefer 15" with the taller sidewall, keeping more with original wheels and tires, and what the car was designed for by the Oldsmobile Design Studio.

Olds64

x2

Fun71

I think you can get Mickey Thompson radials in that size, too.

droptopron

Unfortunately, 15" tires are going the way of 14" tires. The suppliers are drying up, and with it you get less value for your money. Tirebuyer lists only two tires in 255/60-15. The Cooper @ $117 w a T Rating and BFG's t a hefty $165 with an S (lower) speed rating.

I like the idea of a 255/45-17 to maintain the overall height. Tirebuyer lists tires starting around $125 but that goes all the way up to W speed rating which is much higher and should handle noticably better

joe_padavano

S is SUSTAINED 112 MPH operation, T is sustained 118 MPH, and W is sustained 168 MPH. Any of them will be more than adequate for a 1970s vintage Cutlass.

droptopron

I know what the speed ratings mean, thanks

RandyS

Guess I'm just an old fart, but the huge rims with banana peel tires doesn't cut it. I like the more traditional wheel sizes on muscle cars. I recently put a set of 295/50-15's on 10" wheels on the back of my 66, and I love the look.

Fun71

https://www.summitracing.com/parts/mtt-6028/overview/
Mickey Thompson Sportsman S/T Radial
255-60-15
T Speed Rating
$134.56

droptopron

I gotta say, I bought Radial TA's back in 2014 (I believe) when I had my 1979 Trans Am. Those cars need white letter tires and Radial TA's look great on them. However, at the time, I think they were $15 more than a Cooper would be. These days, you have to be out of your effing mind to pay that much more for a tire that is no better.

442fanatic

I agree, this has been debated here before on whether to update to larger rims or stay the same.

Personally I like the stock look of the super sports rims. If I acquired a car that had a distasteful to me hub cap, then perhaps looking at new rims would be an idea, along with looking at the better rim option, if any, for that model in that year.


I search ebay and craigslist for mid 70s cutlasses for sale, and large 20's and 22's on these cars to me looks funny. At car shows it gives us something to chat/laugh/debate...

Rocketbrian

To each their own. I would pay 50 -100 more for a tire to have a correct name on the sidewall. These cars we love came with B.F. Goodrich, Firestone, Goodyear or Uniroyal. There is no way I would ever have Cooper on my car. Cooper I believe made baseball gloves and other sporting goods and Cobra is a Ford name. In my opinion you might as well have Walmart on the sidewall. Perhaps I am out of my mind but at least I am principled.

442fanatic

Very true on those brands whom made the rwl tires.
I went with Cooper personally as Cooper was once advertised by Paul Harvey, at that time the last American owned and American made tire. However being made in America has changed, as the Cobras are made in Mexico, but the all terrains I had on my truck were made in USA.
Like a prior poster said, companies that offer RWL tires, in 15" size, are now down to a few. I liked the look of the Cooper Cobra tires, the tread pattern, and standing out a bit at the shows. Not period correct true, but too each their tastes.

droptopron

To each their own but I don't see it. If you aren't running a repro, restoration style tire (I have Firestone Wide Ovals on mine) I don't see the difference. Plus, these cars were known for either Firestones or Goodyears, BFG wasn't a major supplier to them back then.

droptopron

I know Cooper still manufactures in Ohio, but IDK about the Cobras, These days, Mexico is the good stuff. For my DD (245/45r18) I could only find one tire made in America, and it graded poorly in ice & snow. I ended up with a General tire, which is highly rated & I'm happy with, but they are made in Romania.

oldcutlass

Cooper makes tires for multiple tire brands like Avon (motorcycle tires), Dean, Mastercraft, Mickey Thompson, Roadmaster, and Starfire. They also made all tires sold under the Sears Guardsman name. Cooper manufactures tires for Discount Tire Company under the Arizonian brand name, and Futura Tires for Pep Boys. Cooper Tire also manufactures Hercules branded tires in Findlay, Ohio. Cooper tires can be purchased at many tire retailers, like Tire Discounters, Pep Boys, Discount Tire, and more.

RetroRanger

thanks for all the replies

I have a decent driver set of 15x7 SS3s painted black w decent trim rings and d rings, i like the way the rims look.

to go to 17s or 18s is ~$1700

replace tires only ~$500

replace tires an rims w another 15" rim ~$1200

I dont mind the look of the larger rim within reason (18") but for the extra ~$1k it looks like i buy slightly more precise handling and a slightly rougher ride. This will probably be the last set of tires i buy for this car ~2k miles a year, so i decided im just gonna stick w the SS3s and some new 15" tires

billrob71

droptopron

I ended up picking up a set of 17's for mine. I still have my 14's with the repro Wide Ovals. I'll save those for show duty but as far as driving its a night & day difference. I went with a 245/50-17 to maintain an overall height close to stock

I think both look cool

anthonyP

I agree, and the 14/15 inch radials handle just as well as 17 inch & larger low profile tires. The 14/15 inch wheels & tires also seem better proportioned to the original design of 64-88 cars.

therobski

I have GM 15x7 inch big car steelie's on the 64-F-85. My opinion, in the early A-body's, low and straight is the way to go as far as stance and overall appearance. Currently have Hotchkis 1 inch lower springs in the rear and will replace to those with 2 inch to hopefully to level it out. Recently had the 3 inch mandrel exhaust installed an mentioned to them that I'm dropping the rear of car another inch and they said I should not have any clearance issues with their work. That said, if you guys install rear coil overs with a 2.5 or 3 inch exhaust you could have clearance issues-just saying....

71 OLDS

I went with 18" SS1s with 45 series sidewalls on the tires and the BFG RWLs. You don't have to go with the short sidewalls on a 17" or 18" rim. Our wheel wells can take a taller setup with no issues. Gives it the stock appearance but all the benefits of an 18" wheel. i'm running 13" rotors on the front and 12" rotors on the rear.

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billrob71

droptopron

I think that is where a lot of guys go wrong. They go bigger with the rim but too short on the sidewall, decreasing the overall height too much. My set up is 26.7" & 26.6" F & R. The G70's were 26.8"

71 OLDS

Here are the details on my set up for reference:

Front Tires/rims- 18x8 rims 5.25” BS- w/Nitto*** 555 255/45/18s 10”sw – 26.97”d

Rear Tires/rims- 18x10 rims 6.0” BS w/Nitto*** 555r 305/45/18s drag radials 12.02”sw – 28.78”d

***Nitto words sanded off and BFG Raised white letters glued on for show***

The ride is amazing with this setup and handling is off the charts but I also have upgraded everything for the best suspension geometry and steering geometry possible on a stock frame (AFX spindles, upper & lower control arms, chassis brace, Lee 800 steering box etc). All of those upgrades plus this wheel and tire combo allow for the best street, track (1/4 mile/ 1/8 mile), or autocross handling by tuning the dbl adjustable shocks, the rear sway bar, and rear relocation brackets accordingly. Hoping to get some 1/8 mile and autocross in before year end and if so will update everything on my ongoing post on this site.

-Joe

frankr442

14 inches and proud.

Kevin11

I struggle with this debate as well.

I'd love 17" wheels...I think they'd offer a great balance between that muscle car sidewall beef aesthetic (and still hit that 26-27" OD with the tires), while still being taut enough to let the suspension actually do its job. It's a bummer that no 17" tires have RWL off the shelf...at least that I can find. Yes, I could use wheel paint or glue-on decals, but you know what I mean.

Coming from the world of imports where you're never for want looking for anything in a 5x114.3 bolt pattern, I'm actually stunned at how little selection there is in the 5x120.65 realm, especially in the 17" size. Of course, if you want a chunky 5-spoke torq thrust-type wheel, you're set (nothing against 'em, just not for me). Anything appreciably different than that, be ready to spend some cash on Rushforth/Budnik/Forgeline/Weld/etc. wheels.

Also frustrating is the weight on some of the non-forged wheels. It's hard to consider any new wheels--regardless of diameter--an upgrade if they're pushing 30 lbs each.