Question about Tire /Wheel Sizes for 1937 Buicks

I have recently purchased a car that I have wanted for over 30 years. While I have been in the antique car hobby for a while, this is my first Pre War Buick.

I recently picked up my 1937 Century Model 61. I have not yet received a factory service manual but will shortly. The car came with a set of four Coker Classic P215/75R15 Radials on it. With the car I also received a new unused set of 8.20 X 15 Firestone Wide Whitewall Bias ply tires. In looking at the owner's manual and other online research, it appears that the 1937 Century originally came with 7 x 15 tires. I would like to use the 8.20 X 15 tires since I have them. I would be interested in pros and cons on using these tires on my Century.

My other tire related question concerns the current sidemount spares. I have checked and found that the sidemount spares are both 6.50X16 bias ply tires. Without actually trying them yet, I am wondering, will these wheels fit on my Century? My research tells me that the Special, Roadmaster, and Limited would have used 16 inch tires. Will these Wheels fit my Century? If so, I would think they would be OK as spares, but obviously I can't mix 15 and 16 inch tires for routine use.

Matt, congratulations on a STRAIGHT EIGHT Buick. Now you have a REAL Buick!:cool:

I believe you will find the 16 inch wheels will work.

Ben

Thanks. I thought that they probably would work, but figured I would ask the experts before I went to the trouble of trying them. Now I am intrigued to try to figure out why they chose to use 15 inch wheels and tires on the Century when all of the others used 16 inch wheels and tires.

Any thoughts on the 8.20 width 15 inch versus the 7.00 width 15 inch tires?

Congrats on your new baby!

I always figured, since the diameter of a 6.50-16 tire is the same as a 7.00-15, the smaller wheel with a bigger tire was used on the Century to support the greater weight of the 320 engine. Same diameter tire kept the scale the same, as Special and Century used the same bodies from the cowl backwards. I think bolt pattern is the same for both wheels, so maybe OK for an emergency? I ran radials on my 38-41 for years, loved them. Wouldn't go back to bias ply, especially if they needed inner tubes. Century has a 5.5 inch rim. Is that within the recommended rim width for your 8.20-15's?

Thanks for your information. I still have a lot to learn on this issue. I will have to check on the rim recommended for the 8.20-15's. They came with the car so about all I know about them is that the previous owner of the car had them. He is a dealer who has had many different 36-38 Buicks and other similar cars over the years and included them with the sale but I don't know if they were specifically purchased for this car. While the car rides OK with the radials, I tend to be one of those purists who like to use bias ply tires on cars that originally came with bias ply tires. I am OK with the radials for now but will be switching to bias ply tires in the future. Since I have these, I would obviously prefer to use them if they will work instead of buying another set.

If you have any questions about 1937 or 1938 Buicks and excellent source of good information is the old Torque Tube magazine of the 37 -38 Buick club.

Here is an index of articles You have to look around a bit. There is a downloadable by Frank Freda at the top.

http://www.1937and1938buicks.com/The-Torque-Tube/The-Torque-Tube.htm

Thanks. I do have to look around that site a bit more. It looks like there is a lot of information there but I had not have much time to poke around there yet. I will look around there a bit more this afternoon.

I spoke with the folks at Coker and they said that the 8.20 X 15 tires will be fine on the original Century wheels. The tires will be about an inch wider and about a half an inch larger diameter, which I think will actually make the slightly off speedometer read a little closer to actual speed.

Hi Matt,

looking forward to seeing your pictures of the new baby -- maybe Tuesday?

I ran over-sized tires on my '34 for years until the restoration -- it did fine, gave a nice ride, and had more rubber on the road. Another benefit was that the larger tires reduced the engine revs/mile - almost like a mini-overdrive.

Congratulations on a great car. You know how much we enjoy our all-original '37 Roadmaster Phaeton. Yours has the same driveline without the excess bulk - a factory hotrod !! -- but then, you probably know the local law enforcement (LOL).