coltsneckbob

My 1970 originally came with G-70s. After looking up several charts I determined that that a P235-70R14 is the closest in diameter to that original tire. I have SSII wheels that are 14". My problem is that I cannot find a P235 in 14". Are they made anymore? Coker doesn't carry them. Anyone know of a retailer ??

RAMBOW

a 245/60 R14 would be real close in diameter- would just appear to have a little bit wider sidewall and a tiny bit shorter.

coltsneckbob

Would this tire fit on the wheels? According to BF Goodrich site it says 7 to 8.5 wide wheels. How do I measure the width of a wheel? It is from outside of rim to opposite outside? Or is it some measure within the bead area of wheel?

Also, while I see that the tire is very close in diameter it is also to be almost 7.7 inches in tread width......that is 1.1 inches wider then a P235......am I getting close to being too close to hitting a fender?

RAMBOW

Your stock wheels are likely 7" wide if thye are are the original 1970 wheels.
1 inch wider would be 1/2" on each side.

Go take a look at your car and see how much room you have right tnow between the fender and the tire- i'll bet there is a lot of room.

Allan R

I share your concern. Just spent the last 20 minutes searching the web for 235's in your size. Holy Cow! Nothing, just like you said!

My 72 had the optional G 70 14s when it was new too. What I've got on it right now are Kelly Chargers with a 225/70/14 I know I can get this size from a lot of manufacturers. 225 is a real good width for the car and creates no clearance issues at all. They are mounted on 14X7" SS111s with no issues. I have another set of SS11s in the garage that are 14X7 that I plan to put another set of 225/60/14s on (might need to watch my speedo a bit by changing the size like that).

As far as measuring? Not outside to outside. Measure from the inside bead to inside bead and it should be 7". The inside bead is where the tire bead will seat itself inside the rim. The SS11's were also made in 6" so check carefully. If your car has front drums, they might be 6". If it has discs, the rims must be at least 7" to clear the calipers.

Wish I could find the tire you're looking for. Maybe someone else knows? To me it's not that critical since my car is only for pleasure and show. Your car looks drop dead gorgeous just the way it is. So anything you do to it will likely only make it better. Good luck with your search!

joe_padavano

I think you need to go back and check your math. A 235/70-14 is 26.95" in diameter. A 245/60-14 is 25.57". Not even close. I've run BFG 245/60-14s on several A-body Oldsmobiles and in my opinion the don't look very good. There's just way too much daylight between the tire and the fender at stock ride height.

I suspect you don't want to buy new wheels, but I've found that the BFG 255/60-15s on 15x7 SSIIIs fit nicely and look great. They are withing 0.1" diameter of the 235/70-14s that you want.

ELECMAN

BOUGHT A SET AT SEARS BF GOODRICH radial gt TIRE SIZE WAS 245/60 R14 FOR MY SSll bolt on the price was about $115 a tire looks nice.

coltsneckbob

Allan, thanks very much. I got an inspiration a short while ago and called Thorton Restorations in PA a few minutes ago. They are a well respected Olds restoration shop. He recommended the P225s as filling the wheel well best and of course being very close to the original G-70. I have calculated the diameter differential percentage from the original G-70 and it is under 4%. Put another way is it only 12 more revolutions per road mile then the G-70 (out of a total 752 revolutions for the G-70). This difference is so small I don't think it will be noticable on an analog speedometer. I think it is probably within the margin of error one could expect for an under inflated tire. Now that said the p235s would be less then a 1% error, but they don't seem to make em anymore.

coltsneckbob

Joe, no I do want to keep the wheels the original size. I guess I am zeroing in on the P225s as the most logical/practical choice. Eventually I will purchase another set of SSII wheels and put redline G-70s on them just for show. However, due to the high cost of the G-70s and safety considerations I don't want to run with G-70s for my pleasure cruising.

joe_padavano

Just to clarify, "wheels" are metal, "tires" are rubber. When I said that you probably do not want to change your wheels, I meant the metal 14" wheels. Obviously you are talking about changing your tire size. If you read my post, I was suggesting going to 15" wheels.

coltsneckbob

Joe,
LOL no I understood the wheels are metal. That is why I said I wanted to keep the wheels original (i.e. 14"). I guess was not clear because I was making reference to the entire thread. I am trying to get as close to the original G-70s size in a radial as I can. I currently have P215/70R14s and these are significantly smaller then the G-70. So, what I meant by changing tire size was to not replace the current 215s with new 215s, but instead to move to 225 or even 235 (which are impossible to find for a 14" wheel).

1969w3155

I'm with Joe on this, I have a pair of 245-60 14's on a set of 7x14 SSII's and they are too short, just don't fill the wheelwells and the dia. is wrong. Went with 245-60 15's on a set of 15" SSIII's. Look very good, though not quite as wide as the 255's. 225-70 14 is as close as you are going to get to original size, and as you have found...the 235's just aren't there anymore.

BlackGold

I completely agree with Joe. 245/60-14 is way too small in diameter. It looks funny. I feel that way about anything that's less than 26" in diameter.

If you want to move to thinner sidewalls, like a 60 series, either for performance or because you like the look, then you MUST move up to 15" wheels (or bigger yet). Personally, I like either a 245 or 255/60R15. The diameter is virtually identical to stock, and it has nice width.

Some of you guys need to read up on what the three numbers in metric tire sizes mean. The first number (225, 245, etc) has absolutely nothing to do with the diameter. It's the section width (sidewall to sidewall), pure and simple. It's not until you combine that first number with the other two that you can figure out the diameter. I really wish the standard had simply included the diameter in the size designatiojn to avoid all confusion. Oh well; it's better than trying to figure out what E, F, or G means. Likewise, the second number (60, 70, etc) means nothing by itself. It is the sidewall height, except that it's expressed as a ratio, a percentage, of section width; so it's not until you combine it with the first number that it means anything.

Allan R

If you do find that the speedo error is too much of a problem, you could probably change out the trans speedo gear to one that would calibrate it to within the 1% you are looking for.

FYI, I am VERY happy with the 225/70/14s on my car. They handle like a dream and have a nice wide aggressive stance to the car. The first pic shows the wheel size. Second pic shows proportioning to wheel well. Third pic shows overall proportions and lots of clearance on wheel turn. I was thinking of having the tires reversed to show the raised white letters, but the more I look at it, the more I like just a blackwall. Maybe on the SS11s. Might go with RWLs.

2008_0314MILLER0009.jpg?t=1270853743

2008_0314MILLER0010.jpg?t=1270853860

2008_0314MILLER0029-1.jpg?t=1270853965

71 Cutlass

Personally I do not like a thick sidewall that some are suggesting. I currently have 15 inch rims on my car, but the picture I have as my signature is with 245/60/14 tires. Doesn't look "Funny" at all. Click on my name and go to my public profile for a bigger picture and view the car/tires for yourself. Obviously , beauty is in the eye of the beholder. BTW, the only reason I changed to a bigger wheel is for the reason dicussed here initially...a lack of choice in RWL tires for my car.

Allan R

Your car looks awesome. I looked at your profile picture and you're right, it really looks good! Great color choice and you're right, the tire doesn't look too small. I'm not sure how much difference in height there is between our cars on the side walls of the tires. Maybe 10 mm overall? I like the look of the tire on your car, also like the look of the tire on my car.

60% height on 245 tread is 147 = about a 5.8 inch side height
70% height on 225 tread is 157 = about a 6.2 inch side height

When you compare these numbers, they're not all that much different. Just one tire has more surface area on the road. Tires are a personal choice and I respect all the opinions that have been given. I would guess that the average guy looking at the cars side to side wouldn't be able to tell they were different sizes, since the side heights are compared against the overall car instead of placing the tires directly on top of each other.

71 Cutlass, you might have just persuaded me to look at a set of 245/60/14s for my SS11s. I was originally going to go 225/60/14. I don't expect there's going to be a huge difference in cost per tire between those 2 sizes.

Great information guys!

joe_padavano

Actually, that's ONE sidewall - in other words, that's the difference in radius. The difference in diameter is twice that, which is nearly an inch (OK, 0.826" to be exact).

stevengerard

I have 245/60/14s on my car and I think they look fine, but I am also planning on moving up to the 15" rim as well, just more choices of tire and more likey a better ride to boot/

WhatIf

This is a really cool little site that allows you to plug in rim width and height, then you can see (visually) how tall and wide a particular radial tire will be. Then you can plug in another tire size/wheel width, etc and see (visually) what the difference would be between one choice and another.

http://www.rimsntires.com/rt_specs.jsp