Original Tire Size for 1964 Dynamic 88

[Kaline]

Does anyone know the original tire size for a 1964 Oldsmobile Dynamic 88? I have checked my owners manual and service manual and cannot find this info. I want to cross-reference the original size to a modern tire so my speedometer will read correctly. Any information is appreciated.

[Oldsguy]

I have a reference at home that lists tire sizes as delivered from the factory, will try to remember to let you know. I am willing to bet that it was about 27" tall though. Good luck in your search (note to self, remember, remember, remember.....what?).

[Olds64]

The tires I was looking for on my 64 Olds 98 were 220/75 R 15s. I looked up the original tires size and cross referenced it. That is as close to the orignial tire size.

[Kaline]

Do you mean a 215/75R15 or 225/75R15? Tires in steps of 10mm, such as 185, 195, 205, etc. My B-Body has 14" wheels. Are these original for the Dynamic 88, or should it have 15" wheels?

[Oldsguy]

Book says, 8.00X14 inches, whatever that means......
So yeah, 14 inch is original, as to the 8.00 part, I am not sure.

[Kaline]

OK, that helps me. Using tire data from the Coker Tire website, the equivalent size is P215/75R14 (the size that as on my car), or I could also run a P225/70R14. COOL! Thanks for the info!

Here is a link to Coker's tire size cross-reference chart:
http://store.coker.com/pages.php?pageid=18

[Starfire61]

The 8.00 in the old numeric tire sizing system indicates the section width (not height) in inches at the widest point of the tire.

Here's a good link that explains the different sizing systems:
http://dunlop.buffnet.net/tt101_sizing.html

I don't have literature for '64, but wouldn't be surprised if a slightly larger 14" tire was also available. In '61 & '62, the standard tire on the 88 was an 8.00 x 14, but an 8.50 x 14 was standard on AC cars & optional otherwise.

My 61's & 62's all sport repro bias tires from Coker. I had radials on all of them for awhile & thought the ride was very hard. I had a lot of folks tell me to avoid the bias tires, but I finally opted to put them on my '61 Starfire to bring it to AACA standards. Prepared for the worst, I was astounded at the improvement in the ride. It was a dramatic, night & day change in the ride quality, so eventually I put the bias tires on all my big Oldsmobiles, with similar results. The cars look better too, as they sit a bit higher, & the tall tires tend to fill the wheel wells more than the radials did.

I realize I am in a small minority in favoring the bias tires, but I don't mind sacrificing a bit of handling in favor of that wonderful old big-car ride. I admit, if I wanted to take a Starfire on a slalom course, I'd want to mount a set of radials, but I don't anticipate doing any road rallies in the forseeable future!

[Oldsguy]

Thanks for that info, I sort of suspected it would be width, someplace. I agree with you about many tires today not fitting our older cars height wise. I think filling the wheel well out is very important. I am not surprised to hear about your experience with the bias ply vs. radials either. Taller tire gives you more flex and a softer ride, in spite of the new radial designs that are supposed to be better. Front suspension design may have some part to do with it as well, like Norm has said "The engineers knew what they were doing" in spite of some people say otherwise.

[J-(Chicago)]

I love when the first layer of those tires starts coming off in sugar cube sized chunks. Spraying all over the road and slapping around in the wheelwells.

[Kaline]

Starfire61: Thanks for this input, that is very interesting. However, when you think about it, it does make sense. The bias ply tires have a taller overall height, but the static rolling radius is the same as the shorter radial tire b/c the bias ply tires have more give to the sidewall. That is why the tires fill up the wheelwells more than a radial tire of equivalent size. The original suspension was tuned for bias ply tires, and if the ride & handling engineer on these vehicles did a good job picking spring rates, bushing rates, etc, then tire selection makes a BIG difference. I think most of us just assume that radial tires are better!