MotiveLensPhoto Posted January 21, 2023 Share Posted January 21, 2023 According to the ROA site the correct size tire for 1995 is P225/60R16. The tires on mine are P225/70R17. They are likely in need of replacement due to age anyway and one is now flat, but how serious is it to have these on, ASSUMING the wheels are still original and correct? Link to comment Share on other sites More sharing options...
dship Posted January 21, 2023 Share Posted January 21, 2023 P225/60R16 are the original and correct size. Link to comment Share on other sites More sharing options...
RivNut Posted January 21, 2023 Share Posted January 21, 2023 If you have 17” wheels now, you’ll have to replace them with 17” tires. To put the 16” tires on your car, you’ll need to come up with some 16” wheels. Post a picture of the wheels that are on the car now. Link to comment Share on other sites More sharing options...
MotiveLensPhoto Posted January 21, 2023 Author Share Posted January 21, 2023 9 minutes ago, RivNut said: If you have 17” wheels now, you’ll have to replace them with 17” tires. To put the 16” tires on your car, you’ll need to come up with some 16” wheels. Post a picture of the wheels that are on the car now. My mistake. The tires on the car currently are P225/55R17. I can't imagine a 16" wheel would hold a 17" tire. Link to comment Share on other sites More sharing options...
RivNut Posted January 21, 2023 Share Posted January 21, 2023 No one is questioning the tire size. Post a picture of the wheels and perhaps someone can confirm whether they’re factory or something else. Link to comment Share on other sites More sharing options...
MotiveLensPhoto Posted January 22, 2023 Author Share Posted January 22, 2023 1 hour ago, RivNut said: No one is questioning the tire size. Post a picture of the wheels and perhaps someone can confirm whether they’re factory or something else. My mistake. Here's the best photo I have showing a tire. Link to comment Share on other sites More sharing options...
EmTee Posted January 22, 2023 Share Posted January 22, 2023 The 225/55-17 is the so-called "plus 1" sizing when increasing rim diameter. Increasing the rim from 16" to 17" while reducing the sidewall height by going from a 60 to 55 aspect ratio keeps the tire circumference approximately the same. 1 Link to comment Share on other sites More sharing options...
RivNut Posted January 22, 2023 Share Posted January 22, 2023 That wheel is not a wheel that would have been original equipment on a 95 Riviera. I have some pictures of this car when it was displayed at the ROA meet in 2005. It was shown, along with some others, as one of the cars that came out of the Buick stying studios. Because it was a concept car, I’m willing to bet that the stylists enhanced it a bit with some custom wheels. If your odometer and speedometer are correct, just buy new tires in the same size as what are on the car now. 1 Link to comment Share on other sites More sharing options...
RivNut Posted January 22, 2023 Share Posted January 22, 2023 https://tiresize.com/comparison/ use this tool to compare the two sizes. There’s negligible difference between the two that would adversely effect the speedometer and the odometer. 2 Link to comment Share on other sites More sharing options...
Barney Eaton Posted January 22, 2023 Share Posted January 22, 2023 (edited) Here is a chart that gives you an idea where you should be if you retain the 17 in wheels. The first row show the factory size tire (16 in wheel)... revolutions per mile, at 60 mph and in 10,000 mile what the odometer would read. The next two sizes would be better as they are both less than 5% off what the original size The last one is the size you said is on the car and it is off by 10%....do not buy that size as a replacement. I would choose the 225/60r17 because the revs per mile are lower and it puts less miles on the odometer Specification Sidewall Radius Diameter Circumference Revolutions Speedometer Odometer Difference 225/60-16 5.3" 13.3" 26.6" 83.7" 757/mi 60MPH 10000mi N/A 225/60-17 5.3" 13.8" 27.6" 86.8" 730/mi 58MPH 9638mi 3.8% 225/50-17 4.4" 12.9" 25.9" 81.2" 780/mi 62MPH 10298mi -2.9% 225/70-17 6.2" 14.7" 29.4" 92.4" 686/mi 54MPH 9057mi 10.4% I like this size even better.............. 235/50r17 Specification Sidewall Radius Diameter Circumference Revolutions Speedometer Odometer Difference 225/60-16 5.3" 13.3" 26.6" 83.7" 757/mi 60MPH 10000mi N/A 235/50-17 4.6" 13.1" 26.3" 82.5" 768/mi 61MPH 10144mi -1.4% Edited January 22, 2023 by Barney Eaton (see edit history) 1 Link to comment Share on other sites More sharing options...
RivNut Posted January 22, 2023 Share Posted January 22, 2023 The tire comparison tool says the 225/55/17 will 3 tenths of a mile per hour faster at 90 mph than the 225/6016. Link to comment Share on other sites More sharing options...
MotiveLensPhoto Posted January 22, 2023 Author Share Posted January 22, 2023 Thanks for all the info. I assumed the tires being a little over was insignificant. Not that you can see very well, but the valve stems aren't even visible. I have no idea where they are. Not visible through the slots in the wheel covers. Once the weather improves ... 90 mph? Not in that car. At least not until I get all the other issues up to snuff and probably never. I don't plan on adding too many miles to it ever. Link to comment Share on other sites More sharing options...
EmTee Posted January 22, 2023 Share Posted January 22, 2023 5 hours ago, Golden73 said: ...the valve stems aren't even visible. Could they be on the back side of the wheel? That would be a PITA for maintenance, however, a wheel designer might not that ugly stem to spoil their beautiful wheel... Link to comment Share on other sites More sharing options...
MotiveLensPhoto Posted January 23, 2023 Author Share Posted January 23, 2023 1 hour ago, EmTee said: Could they be on the back side of the wheel? That would be a PITA for maintenance, however, a wheel designer might not that ugly stem to spoil their beautiful wheel... I never thought of that but I can't imagine why one would do that. Something to look for when I fix the flat I have now. Link to comment Share on other sites More sharing options...
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