Radial Tire Advice Needed

I will be replacing the polyglas tires on my car with radials. I understand the closest equivalent tire height available is 245-60-15. Most manufacturers don't really cater to this size anymore, and according to www.tirerack.com, I'm limited to four tire choices -

• BFGoodrich Radial T/A (SR Rated)
• Dunlop GT Qualifier T (TR Rated)
• Kumho Venture ST (SR Rated)
• Yokohama Avid S/T (TR Rated)

There's more choices available in a 255-60-15 size, but a speedometer calibration would be needed.

• BFGoodrich Radial T/A (SR Rated)
• Dunlop GT Qualifier T (TR Rated)
• Firestone Firehawk Indy 500 (SR Rated)
• Goodyear Eagle #1 NASCAR (SR Rated)
• Goodyear Eagle GT II (SR Rated)
• Yokohama Avid S/T (TR Rated)
• Pirelli Scorpion Zero (VR Rated)

Here's the question -

• Should I just stay with the 245-60-15 size, in one of the 4 tires above?
• Go with one of the larger tire options, and get the speedo calibrated. I'd assume this includes a different gear in the trans. How difficult is it to change? How do I calculate the one I need?

TIA

 

You will have fit issues with the bigger tire on the front I believe. It is easy to change the speedo gear in a TH400. The gears are still available through any GM dealership for about $8.50.

 

Thanks Phil.

How about an M21 Muncie?

Also, I've heard (and seen) that there are no clearance issues with the 255 width if your front end is in good shape.

 

Marco, based on My own experience, we tried a 255/60 15 on stock rims, and had clearance problems on the front.
245/60 BFG & Goodyears fit fine, and the speedo was dead on with the factory 3.42s & stock transmission gearing, using a measured mile & stop watch.
If you go Larger rim, and lower profile tire, you may find overall diameter to be close enough not to worry about recalabration on the speedmeter & odometer.

 

Thanks JR -

I'm not looking to change my 15x7 rims - just getting a safer tire for cruising.

It seems I'm 'stuck' with the BF Goodrich tires as Goodyear doesn't offer any 245 tires

OK - what's the best 245 tire???

 

Marco, when taking my tranny out of my car, I found it's really easy to change the gear in the muncie. Follow the speedometer cable down to the case and the piece that's bolted there is where the gear is. Just unbolt it and the gear will come out. I would record the speed of your car at 2000 rpms before installing the new tires to be on the safe side.

 

Thanks Rob :TU:

I'm think I'm going to stay with the 245 size - due to JR's evaluation above.

What size are you putting on your 'Green monster'? :Brow: - You're going to need a lot of rubber :bglasses:

 

245 TA s are the best choice and a good tire for the money. It is a Michelin company. Michelin led the pack with the radial tire. I have heard plenty say the 255s rubbed a bit on the front.



Check the Wall Mart installed price and the BJ's and Sams. You may not save a thing when the smoke clears by going mail order.

 

Sam's Club definitely has good prices. And they have a big book with all kinds of tires. If they don't have it in stock, they'll order it for you. It only takes a week or so. I did that once before and was very happy with their service.

 

I got some rubber for the rear :grin: I'm running the 17" Torque Thrust II's with 245/45/17 up front and 275/40/17 in the rear. I was reading where 315's might work, but I'll need a 11" wide wheel. I'll be getting the engine on Wednesday so hopefully in a couple weeks I'll have it together. I needed a custom flywheel as I'm using the Muncie M-22 from Auto Gear.

 

new tires

if the ride height on the front of your car is not up to spec, the 255R60 might scrub on a tight turn into or exiting a driveway .
when i upgrade to 15" buick ralleys , i will go the 255R60 size all around with bfg t/a tires . as far as i am concerned , they are a good tire . as for the recalibration of the speedo , i will go by the tach after detemining the difference thru a measured mile between the old tires at 60 mph & 60 mph with the new tires & rims , by using the time difference to determine the new tach rpm . or just pass thru a radar trap & let the policeman tell me how fast i were travelling !

 

I have 235/60/15 Avids on my 71.
Great tire. Some people think they
do not belong on American Muscle.
Check this site for sizes.

http://www.miata.net/garage/tirecalc.html

John

 

I'll be buying the Yokohama Avid S/T soon. Tire Rack survey rates them much higher than anything but the Firestones, including BFGs. The Avid is rated 118 (T), the BFG 112 (S). I like the tread design better than the BFGs with what appears to be better water channeling. I'll be mounting the white letters inboard, I'm burned out on the RWL look.

I'll be running 295/50-15 and 245/60-15

AND, supposedly the Avids are MADE IN THE USA. I know, it's still a Japanese company but at least they have American employees.
Who owns BFG again...???

 

as for my lesabres and the performance of the Yoko AVIDs....i put a set of Yokohama AVID Touring 235/75/15 tires on my 74 vert last fall and they ride smooth and real quiet. they hold the old heavy cars up easily and track good in the rain.
i put another set (exactly the same size) on my 76 4 door lesabre last week with the same results.
bought them all from tirerack.com for about $255 (after shipping) for the set of 4.
they were ok in the snow .. about as good as the best radials i have had in the snow, but not as good as snow tires.

they are the quietest tire i have ever had on a vert.

 

Grand Am G/T for me... and they do make a 245/60SR15... Ooops I better mention I sold these tires for 10 years, its the only tire I'll put on my cars after that, oh, I'll run Kelly's or Big O's, too, the Grand Am's and Big O's are built by Kelly. The Grand Am has a 500 treadwear rating, the BFG and a couple others I saw on www.tirerack.com only had a 420 treadwear rating.