Tire sizing assistance please

[RSRXION]

OK gang, we've got the 66 Corvette up and running and it drives as it should. Now it's time to replace these 40 year old Goodyears. The wheels are 9's in the rear and 7's in the front and I'm leaving them on the car. The problem is that the tires on the car now are a little wider than I'd like. The front tires rub the fenders on a hard turn and the rears seems to bulge out at the sidewalls more than I'd like. I need to replace them but what should I use to get the car down on the ground a little, avoid the rub and still keep the look of bigs and littles ?

The tires on the rear are F60-15 and the tires on the front are L60-15. Obviously they are bias ply tires. I'm going back with a radial but I need some input on tire sizing. Your thoughts ?

Thanks, Dean

[Beagle]

235 60 15 is about as wide as I would go on a 7" (Monte Carlo rim? I thought Vettes had 8" 's? ). I think I put a 245 60 15 on my Elco that had Monte Carlo rally's on it, and they were a bit too wide on the rim (looked too wide on it). You might want to go a little less, but I think those areo about the right size. If you go smaller, like a 225, it might prevent the rubbing.

probably a 275 60 15 or 295 50 15 in the back - you're not going to have a helluva lot of choices here. Drag radial in a 275 60 would probably look pretty wicked. If they are 8" rims, they will be right at the limit of looking too big for the rim. If they are 9" , they should fit without a problem and look fine.

/edit - found a conversion sheet that I don't know how accurate it is but it sure seems about right. The Tirerack.com site can show you dimensional data on their tires... http://www.teufert.net/speedo/tires.htm

[oletrux4evr]

Here's one of many size calculators. It does diameter, width, sidewall height, revolutions per mile and gear ratio comparisons side by side.

http://www.tacomaworld.com/forum/tirecalc.php

[fast Ed]

F60-15 converts roughly to a 225/60R15, and L60-15 to a 275/60R15.

So maybe consider 215/60R15 and 255/60R15, those sizes are both available in the popular BFG Radial T/A lineup.


cheers
Ed N.

[RSRXION]

Thanks for the input guys. Here she is with the existing tires and wheels.








See what I mean about the rears being too big for the wheels ?

[Beagle]

275 60 15 on the rear won't look as wide, a 295 50 will look kinda like the ones on there I bet. A 225 60 15 on the front, I'd think they would look about right and maybe not rub.

Talk to your tire dealer and see if they'll let you mount them, take a look at it and see what you think. If they use lube like they are supposed to it's not going to hurt the tire to mount / unmount it. Depends on the manager I suppose.

[67ragtop]

Here are two web sites for wheel and tire sizing that I have used to install 17 in wheels and tires on my Malibu

http://www.discounttiredirect.com/direct/assignTireVehicle.do?yr=1967&mk=CHEVROLET&vid=008872

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

The second one compares what you have with what you want.

[Dan Barlow]

While I would trade you cars I think you need wheels in the back 1 1/2 to 2 inches smaller with some 255-265 x 50 's in the rear.

[Barry Donovan]

235 60 15 is about as wide as I would go on a 7" (Monte Carlo rim? I thought Vettes had 8" 's? ). I think I put a 245 60 15 on my Elco that had Monte Carlo rally's on it, and they were a bit too wide on the rim (looked too wide on it). You might want to go a little less, but I think those areo about the right size. If you go smaller, like a 225, it might prevent the rubbing.

probably a 275 60 15 or 295 50 15 in the back - you're not going to have a helluva lot of choices here. Drag radial in a 275 60 would probably look pretty wicked. If they are 8" rims, they will be right at the limit of looking too big for the rim. If they are 9" , they should fit without a problem and look fine.

/edit - found a conversion sheet that I don't know how accurate it is but it sure seems about right. The Tirerack.com site can show you dimensional data on their tires... http://www.teufert.net/speedo/tires.htm

this is for monte? that is where I went too. just right.
235/60 rear.
the front was too skinny. can't remember what I did there. Also a 60, but wrong.
maybe front does 215/60, I was doing 205? really can't remember the front.

[milner351]

Aluminum slots rule!

Tire rack and several other sites have tire size calculators - I've built one in excel, but it's easy to do free hand - several wheel / tire sites also have recomendations of wheel width and tire width.

In general - take the milimeter width and convert that to inches... ok, here we go.

225 / 60 - 15

225mm wide - convert that to inches = 225/25.4 = 8.86 inches wide.

Height of sidewall = aspect ratio(which is a percent) x width = 8.86 x 0.60 = 5.31 inches rim bead to tread.

So - total height of tire not taking into account the deflection due to loading = 5.31 x 2 + 15 = 25.62 inches tall.