When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I am considering upgrading the tires and wheels on my 81 to 17" or possibly 18's. I think for the performance and looks it's a good upgrade and sounds like many have done this. However there seems to be a lot of info to process and consider before doing this. First is understanding tire sizes, wheel/rim sizes and offset or backspacing. My question is, first, is there any comprehensive guide to what works and what doesn't as far as suspension or frame modifications when doing this? For example a lot of people talk about relocating the parking brake mount which sounds fairly straightforward. There is also spacers required sometimes. I guess it depends on how wide you want to go. For my situation I just want a good/mild upgrade and nothing extreme. I want something with better tire options and handling. Maybe someday I will do some autocrossing - not sure but possibly.
Currently my car is stock with regards to wheels and tires. 255-60-15 all around on stock wheels. I think I would want to upgrade to a 17" tire/wheel combo, but how wide? From what I can look up, stock wheels are 15 x 8 with -19mm backspace so from there where do you go? Do I stay with 255 wide, or try to go wider? And then there is tire height, stock are 27.05" high and I think I would want to stick with something close to that. Also there some people go with wider tires in the back, not sure I want to do that either. Sounds like it would be easier to keep them all the same.
So if I go with something like 255-50-17's they are about exactly the same height at 27.05" and also the same width. So these should be no problem - right? Then I start shopping for tires and wheels... Is this a popular combo? By the way I think I read almost every page of the very helpful stick thread on Tire/Wheel combos.
Well at least on Summit there are only two options available for 255-50-17. Also on Tire Rack. Looks like that is somewhat of a uncommon size. Might have to consider some other sizes. I will go through the linked threads again. I guess this is where people start going with wider tires and messing with backspace and all that. I guess I'm looking for a common proven combination in 17 inch wheel size that works and is readily available. Something a lot of people go with. Finding it hard to narrow that down.
I really struggled with this also because the tire options were pretty limited in certain sizes, and I didn't want to go to 18" (personal preference).
Ultimately I went with 17x8's on all 4 corners with 245/45/17's, I do like the way it turned out. One note, I had an advantage of both front and rear mono leafs to be able to lower the the front and rear.
There is no secret or magic to swapping from 15" to 17" or 18" wheels and tires.
That is unless you want a modern wheel that is not really made or designed to fit a C3 Corvette.
Then you would need to factor in what wheel spacers, or frame and or body modifications you would need to get the wheels and tires to fit.
If you stick to what you mentioned in your above post you should be fine without even moving the parking brake cable mounting bracket.
I swapped from the stock 15" rally wheels to 17" X 8" wheels with the oem 4.0" backspacing on all four corners.
I'll be mounting 255-50-17's all around because I want the taller sidewall between the wheel and tire to retain some of the OEM 15" wheel and tire design profile.
In my opinion, 18" modern wheels don't fit on a classic Corvette.
Again just my opinion.
My decision to go with 17" wheels was mainly because I wanted to install 6 piston Willwood brake calipers on the front and 4 piston Willwood brake calipers in the rear and the front wheel to caliper tolerances where just a little to close to run 15" wheels.
The secondary factor was there are many more choices of performance tires available in 17".
So if I go with 255-50-17's do I need to do anything to the suspension? Like stiffer springs, different shocks, upgraded sway bars? Seems like it should all work together. Maybe just upgrade those things over time as I can.
You shouldn’t have to do anything except mount the new tires and wheels as long as you stay with the 255-50-17’s.
To be sure, remove one of your wheels and measure the backspace, then measure the tire diameter and width.
As long as you duplicate the back spacing of your current wheels, the width and diameter of your current tires, you should be fine.
Depending on the tires you choose, you should experience a big improvement in ride and handling.
Upgrading and fine tuning the suspension will increase the experience even more.
I went with Van Steel for all my suspension upgrades.
You can easily upgrade a little at a time or jump into a full new suspension.
They have been in business for decades and their technical support people really know their stuff.
Well at least on Summit there are only two options available for 255-50-17. Also on Tire Rack. Looks like that is somewhat of a uncommon size. Might have to consider some other sizes. I will go through the linked threads again. I guess this is where people start going with wider tires and messing with backspace and all that. I guess I'm looking for a common proven combination in 17 inch wheel size that works and is readily available. Something a lot of people go with. Finding it hard to narrow that down.
Well at least on Summit there are only two options available for 255-50-17. Also on Tire Rack. Looks like that is somewhat of a uncommon size. Might have to consider some other sizes. I will go through the linked threads again. I guess this is where people start going with wider tires and messing with backspace and all that. I guess I'm looking for a common proven combination in 17 inch wheel size that works and is readily available. Something a lot of people go with. Finding it hard to narrow that down.
I really struggled with this also because the tire options were pretty limited in certain sizes, and I didn't want to go to 18" (personal preference).
Ultimately I went with 17x8's on all 4 corners with 245/45/17's, I do like the way it turned out. One note, I had an advantage of both front and rear mono leafs to be able to lower the the front and rear.
I went with 18's all the way around. I live in Chardon/Concord. I've been SLOWLY working on a 70 coupe for quite a while but picked up 18's last year from Summit. Let me know if you want to take a look.
I am considering upgrading the tires and wheels on my 81 to 17" or possibly 18's. I think for the performance and looks it's a good upgrade and sounds like many have done this. However there seems to be a lot of info to process and consider before doing this. First is understanding tire sizes, wheel/rim sizes and offset or backspacing. My question is, first, is there any comprehensive guide to what works and what doesn't as far as suspension or frame modifications when doing this? For example a lot of people talk about relocating the parking brake mount which sounds fairly straightforward. There is also spacers required sometimes. I guess it depends on how wide you want to go. For my situation I just want a good/mild upgrade and nothing extreme. I want something with better tire options and handling. Maybe someday I will do some autocrossing - not sure but possibly.
Currently my car is stock with regards to wheels and tires. 255-60-15 all around on stock wheels. I think I would want to upgrade to a 17" tire/wheel combo, but how wide? From what I can look up, stock wheels are 15 x 8 with -19mm backspace so from there where do you go? Do I stay with 255 wide, or try to go wider? And then there is tire height, stock are 27.05" high and I think I would want to stick with something close to that. Also there some people go with wider tires in the back, not sure I want to do that either. Sounds like it would be easier to keep them all the same.
So if I go with something like 255-50-17's they are about exactly the same height at 27.05" and also the same width. So these should be no problem - right? Then I start shopping for tires and wheels... Is this a popular combo? By the way I think I read almost every page of the very helpful stick thread on Tire/Wheel combos.
Anyways.. thanks for any opinions.
275 40R 18 tires on 18x 9.5" 4.75" back spacing. Factory 78 with VB&P rear slalom rear spring kit. No modification required on my car. This is 26.7" vs factory 27"
Put American Racing 18's with Firehawk tires.
8" front 245/45
9.5" rear 275/40
Rear is 5.25 BS. Moved the e-brake bracket to the top.
speedo is correct
something to think about
I'd run all 4 the same width for ease of maintenance AND NOT
run directional tires that way you can carry a spare, that way in case you have a issue you can swap out any of the 4
03-17-2022, 12:37 PM
Tire and Wheel upgrade confusion
