Tires
05-15-2015, 08:51 PM
#41
Intermediate
Member Since: Mar 2007
Location: Maryland
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I appreciate the input!!! I have one yes and one frame rub (which I can handle if it is only at full lock) Has anyone actually put 255/60/15 on an early (70 coupe) C3. Thanks again for every ones help!!! I am trying to make the car a little more fun to drive with the classic look. Running F70's and hating the driving experience 
05-15-2015, 09:45 PM
#43
Burning Brakes
Look at tire Conversion Charts online and they will tell you height and Width
The 255 60 15 will fit on a 7 Inch Rim but really need an 8 Inch rim to sit lower another thing to think about.
Last edited by MakoJoe; 05-15-2015 at 10:10 PM.
05-17-2015, 04:33 AM
#45
Melting Slicks
It is always interesting to watch the thread go to arguments around what is optimal tyre sizes etc.
I have to agree with the comments about tyre fitment charts. Manufacturers will always have the maximum # of listed wheel sizes to optimise sales but for each tyre there is an optimum rim size.
You can deviate from that size a bit with little change but go way off and it will deteriate quickly.
Compensating with more pressure for the excessive sidewal movement is an option but then it changes ride characteristics.
It is always interesting to test the same width rim with different size tyres and compare corner turn in, breaking, fast response etc. the differences can be amazing.
While it's the fronts that are most noticeable it's amazing how much movement you can get in rear tyres under cornering and the largest tyres can look almost dangerous if you mount a camera to the underside and watch a fast corner.
But in the end it all comes down to what you use your Vette for, how fast you drive, the type of roads and what you think is good handling.
Everyone has a different view of handling based on your experience and type of cars you have driven.
So if someone is happy with the 295's great, others may not be because of looks, handling etc, it's all personal preference.
And wouldn't it be a sad and boring place if we were all the same. -
I have to agree with the comments about tyre fitment charts. Manufacturers will always have the maximum # of listed wheel sizes to optimise sales but for each tyre there is an optimum rim size.
You can deviate from that size a bit with little change but go way off and it will deteriate quickly.
Compensating with more pressure for the excessive sidewal movement is an option but then it changes ride characteristics.
It is always interesting to test the same width rim with different size tyres and compare corner turn in, breaking, fast response etc. the differences can be amazing.
While it's the fronts that are most noticeable it's amazing how much movement you can get in rear tyres under cornering and the largest tyres can look almost dangerous if you mount a camera to the underside and watch a fast corner.
But in the end it all comes down to what you use your Vette for, how fast you drive, the type of roads and what you think is good handling.
Everyone has a different view of handling based on your experience and type of cars you have driven.
So if someone is happy with the 295's great, others may not be because of looks, handling etc, it's all personal preference.
And wouldn't it be a sad and boring place if we were all the same. -
05-17-2015, 06:59 AM
#46
Le Mans Master
It is always interesting to watch the thread go to arguments around what is optimal tyre sizes etc.
I have to agree with the comments about tyre fitment charts. Manufacturers will always have the maximum # of listed wheel sizes to optimise sales but for each tyre there is an optimum rim size.
You can deviate from that size a bit with little change but go way off and it will deteriate quickly.
Compensating with more pressure for the excessive sidewal movement is an option but then it changes ride characteristics.
It is always interesting to test the same width rim with different size tyres and compare corner turn in, breaking, fast response etc. the differences can be amazing.
While it's the fronts that are most noticeable it's amazing how much movement you can get in rear tyres under cornering and the largest tyres can look almost dangerous if you mount a camera to the underside and watch a fast corner.
But in the end it all comes down to what you use your Vette for, how fast you drive, the type of roads and what you think is good handling.
Everyone has a different view of handling based on your experience and type of cars you have driven.
So if someone is happy with the 295's great, others may not be because of looks, handling etc, it's all personal preference.
And wouldn't it be a sad and boring place if we were all the same. -
I have to agree with the comments about tyre fitment charts. Manufacturers will always have the maximum # of listed wheel sizes to optimise sales but for each tyre there is an optimum rim size.
You can deviate from that size a bit with little change but go way off and it will deteriate quickly.
Compensating with more pressure for the excessive sidewal movement is an option but then it changes ride characteristics.
It is always interesting to test the same width rim with different size tyres and compare corner turn in, breaking, fast response etc. the differences can be amazing.
While it's the fronts that are most noticeable it's amazing how much movement you can get in rear tyres under cornering and the largest tyres can look almost dangerous if you mount a camera to the underside and watch a fast corner.
But in the end it all comes down to what you use your Vette for, how fast you drive, the type of roads and what you think is good handling.
Everyone has a different view of handling based on your experience and type of cars you have driven.
So if someone is happy with the 295's great, others may not be because of looks, handling etc, it's all personal preference.
And wouldn't it be a sad and boring place if we were all the same. -
Your comments are spot on. I generally don't get too involved in these tire discussions since I have found that many folks don't seem to want to acknowledge that changing tire size too much from stock can have detrimental implications on the handling and steering of the the car.
Generally speaking for C3's, these cars either came with 225/70/15 or 255/60/15's. If you just go wider with the tire without maintaining the same or less sidewall, the car will not handle and steer as well as the stock tire dimensions assuming that you cannot go to a higher speed rating than the OEM tire's S/T rating, which you cannot any longer today. So what do I mean?
Say you are starting with a 255/60/15 S rated tire and want to go bigger to a 275/60/15-same speed rating. The wider 275 tire will have significantly more sidewall (in inches) that will flex like a rubber band going down the road-bad idea as long as you are only driving in a straight-line, at a minimum (255/60/15's bounce all over the road since the big sidewall in this S/T rated tire allows way too much flex). This tire will also have on overall diameter that is taller than the stock 255/60/15. Now if you went to a 275/50/15 instead, the overall diameter will be close to the 255/60/15 with similar sidewall size as the the OEM tire-even better if you could go to a higher speed rated Z tire-much less sidewall flex with ultra high performance tires which drastically reduces tire heat buildup at high speeds.
2 other examples to help clarify this issue:
I wanted to improve the tire contact patch on 2 of my Daily Drivers without changing rims. One car had 225/60/16 S rated tires and I did not want wider tires, just much better performance. I could have just went with 225/60/16 Z rated tires but I wanted a little less sidewall flex by reducing the sidewall size so I went with 225/55/16 Z rated tires that are head and shoulders over the OEM tire-BIG difference.
The other car had 225/60/18 H rated tires-too skinny. I went with a 245/55/18 Z rated which has a MUCH wider contact BUT has the same overall diameter as the 225/60/18 BUT has a MUCH stiffer sidewall due to the Z rating.
Somewhat complicated but going to a wider tire with more sidewall in the same speed rating is a step backward IMCO.
I switched to 17 inch rims a few years ago from the OEM rims with 255/60/15 S rated BFG Radial TA's to 255/45/17 Z's and was shocked at how much better these tires not only rode down the road but the handling and steering response was shockingly better than the balloon tire 255/60/15 S rated OEM's.
Last edited by jb78L-82; 05-17-2015 at 07:08 AM.
05-17-2015, 07:11 AM
#47
Le Mans Master
Member Since: May 2008
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2022 C3 of the Year Finalist - Modified
clarification
Your comments are spot on. I generally don't get too involved in these tire discussions since I have found that many folks don't seem to want to acknowledge that changing tire size too much from stock can have detrimental implications on the handling and steering of the the car.
Generally speaking for C3's, these cars either came with 225/70/15 or 255/60/15's. If you just go wider with the tire without maintaining the same or less sidewall, the car will not handle and steer as well as the stock tire dimensions assuming that you cannot go to a higher speed rating than the OEM tire's S/T rating, which you cannot any longer today. So what do I mean?
Say you are starting with a 255/60/15 S rated tire and want to go bigger to a 275/60/15-same speed rating. The wider 275 tire will have significantly more sidewall (in inches) that will flex like a rubber band going down the road-bad idea as long as you are only driving in a straight-line, at a minimum (255/60/15's bounce all over the road since the big sidewall in this S/T rated tire allows way too much flex). This tire will also have on overall diameter that is taller than the stock 255/60/15. Now if you went to a 275/50/15 instead, the overall diameter will be close to the 255/60/15 with similar sidewall size as the the OEM tire-even better if you could go to a higher speed rated Z tire-much less sidewall flex with ultra high performance tires which drastically reduces tire heat buildup at high speeds.
2 other examples to help clarify this issue:
I wanted to improve the tire contact patch on 2 of my Daily Drivers without changing rims. One car had 225/60/16 S rated tires and I did not want wider tires, just much better performance. I could have just went with 225/60/16 Z rated tires but I wanted a little less sidewall flex by reducing the sidewall size so I went with 225/55/16 Z rated tires that are head and shoulders over the OEM tire-BIG difference.
The other car had 225/60/18 H rated tires-too skinny. I went with a 245/55/18 Z rated which has a MUCH wider contact BUT has the same overall diameter as the 225/60/18 BUT has a MUCH stiffer sidewall due to the Z rating.
Somewhat complicated but going to a wider tire with more sidewall in the same speed rating is a step backward IMCO.
I switched to 17 inch rims a few years ago from the OEM rims with 255/60/15 S rated BFG Radial TA's to 255/45/17 Z's and was shocked at how much better these tires not only rode down the road but the handling and steering response was shockingly better than the balloon tire 255/60/15 S rated OEM's.
Generally speaking for C3's, these cars either came with 225/70/15 or 255/60/15's. If you just go wider with the tire without maintaining the same or less sidewall, the car will not handle and steer as well as the stock tire dimensions assuming that you cannot go to a higher speed rating than the OEM tire's S/T rating, which you cannot any longer today. So what do I mean?
Say you are starting with a 255/60/15 S rated tire and want to go bigger to a 275/60/15-same speed rating. The wider 275 tire will have significantly more sidewall (in inches) that will flex like a rubber band going down the road-bad idea as long as you are only driving in a straight-line, at a minimum (255/60/15's bounce all over the road since the big sidewall in this S/T rated tire allows way too much flex). This tire will also have on overall diameter that is taller than the stock 255/60/15. Now if you went to a 275/50/15 instead, the overall diameter will be close to the 255/60/15 with similar sidewall size as the the OEM tire-even better if you could go to a higher speed rated Z tire-much less sidewall flex with ultra high performance tires which drastically reduces tire heat buildup at high speeds.
2 other examples to help clarify this issue:
I wanted to improve the tire contact patch on 2 of my Daily Drivers without changing rims. One car had 225/60/16 S rated tires and I did not want wider tires, just much better performance. I could have just went with 225/60/16 Z rated tires but I wanted a little less sidewall flex by reducing the sidewall size so I went with 225/55/16 Z rated tires that are head and shoulders over the OEM tire-BIG difference.
The other car had 225/60/18 H rated tires-too skinny. I went with a 245/55/18 Z rated which has a MUCH wider contact BUT has the same overall diameter as the 225/60/18 BUT has a MUCH stiffer sidewall due to the Z rating.
Somewhat complicated but going to a wider tire with more sidewall in the same speed rating is a step backward IMCO.
I switched to 17 inch rims a few years ago from the OEM rims with 255/60/15 S rated BFG Radial TA's to 255/45/17 Z's and was shocked at how much better these tires not only rode down the road but the handling and steering response was shockingly better than the balloon tire 255/60/15 S rated OEM's.