Babys Got New Old Shoes

[55 Fargo]

Hi all, got 4 tires from a someone I know, they are P215 75 15, not quite what I was looking for, but for $40 I had to buy them, there still in decent shape. They were mounted on my rims using the 2 piece brass valve stems. Even on of the powder coted rims, that I thought was iffy, because of pitting, will keep my fingers crossed on this one. The young guy that did them, said they were fine and did not leak after testing, we will see, still have some newer tubes, just in case.

These tires have relaxed my engine a bit, not howling as much at 50 to 55, the speedo is closer to the correct speed also. They are quite a bit taller than the P205 70 15 tires taht were on before, but they are also slightly narrower.

Normally I would not buy used tires, but he had them on his 48 Chrashler, next set will be cokers for sure;)

[BobT-47P15]

Fred, I (and others) think that the 215 size is nearer original than the 205.

Should give the engine a little break.

[Norm's Coupe]

Fred, I (and others) think that the 215 size is nearer original than the 205.

Should give the engine a little break.

Bob, about a month or so ago I called Firestone to see which modern radials would replace 670 x 15's. He checked his books and said the 205 x 75 x 15 was the correct one to use according to his books. The 75 is taller than the 70 series. Since Fred's new set of tires are the 75 series, that's probably why his speedo is more accurate now.

[55 Fargo]

That is true Norm, the only other thing is the diff gearing, it is still throwing out the speedo accuracy, it is either a 4.3 or a 4.1, the factory correct diff for the trans I have or more correclty the trans speedo gear is 3.9. Going to a 4.3 diff, with a 3.9 speedo gear, will throw out the speedo by 8 to 10 mph.

The correct tire size for 6.70 15 is P205 75 15, for 7.10 15 its P215 75 15, according a chart i have on my desktop..........Fred

[BobT-47P15]

I had 205s on my car once, they caused it to sit a little lower. When I put on

6.70 x 15 bias ply, the car sat higher.

[Norm's Coupe]

Bob,

That's probably because the radials flattened out on the bottoms like all radials do. Bias tires don't do that as much unless they are low on air. Also, the 75 series is not a perfect match to the bias tires, but are the closest without going larger. It's only about 1/2 inch or less difference in the diameter between the two though according to the guy at Firestone.

[55 Fargo]

The 6.70 15 Bias ply tire is 27.4 inches in diameter, the P 205 75 15 Radial tire is 27.2 inches in diameter, only .20 of an inch difference in size...........Fred