Speaking of Tires

[turbomangt]

Went shopping today to get some prices to replace my bad years with 34,000 miles/aksed the guy at NTB what size I could go with on my GT if I wanted something wider. He suggested 225/45/17 they were $125 a tire. Sears wanted like $200!!! for the Goodrich same size. Would I be better of with a 215/50/17? Gary[:I][8)]

[CREWZIN]

Gary,

Here's one of the tire calulating sites:

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

You put your original tire size in the left side and the size your looking at in the right side. You'll be able to see how far off the original size is and what it will do to your PT.

[Mike-in-Orange]

quote:Originally posted by turbomangt

Went shopping today to get some prices to replace my bad years with 34,000 miles/aksed the guy at NTB what size I could go with on my GT if I wanted something wider. He suggested 225/45/17 they were $125 a tire. Sears wanted like $200!!! for the Goodrich same size. Would I be better of with a 215/50/17? Gary[:I][8)]

I've got 225/45/17s on my car and love them. A lower profile tire can give you a rougher ride due to less sidewall height to absorb impact. Looking at the numbers you give the 45 series will give you a sidewall that is not quite 1/4" shorter. That 1/4" doesn't sound like much, but I've never done a side by side comparison.

[nozzano22]

The other option I was looking at was bumping up to something like a 235/45/17. Since the first two numbers relate to each other, by bumping the first and dropping the second it gives a wider tire that has the same sidewall height. Since I installed my lowering springs, I do not want to give up any more sidewall.

Mike

[Cal Cruzer]

quote:Originally posted by Mike-in-Orange

I've got 225/45/17s on my car and love them. A lower profile tire can give you a rougher ride due to less sidewall height to absorb impact. Looking at the numbers you give the 45 series will give you a sidewall that is not quite 1/4" shorter. That 1/4" doesn't sound like much, but I've never done a side by side comparison.

Mike, Actually the 225/45 is the closest size to the stock in a 17. Even though the aspect ratio is only 45, it is 45% of the width and since the 225 is much wider, the rolling circumfrence and diameter is almost exactly the same, just marginally shorter. It is a much closer size than a 215/50. I wrote a spreadsheet a couple years ago that does all the calculations and compares different sizes to stock.

Did you put them on stock rims? I have been wanting to use the 225 but am concerned about putting such a wide tire on a 6 inch rim.

[turbomangt]

I priced a set of Dunlops they were 215/50/17 $500 all four tax/ and balanced out the door. They are trying to sell me an warrenty for another 100 bucks includes free rotations and free flat repairs, someone posted that a 225/45/17 is closer to stock than the 215/50/17, I don't understand the math on that one. 225 is two sized wider ?? please explain that one Gary

[SteelBlueGT]

Cal, I am too not sure about going to 225X45 tires with 6" stock rims! Every tire maker chart seem to inicate that you need 7" or wider rims with 225X45 tires.

[Mike-in-Orange]

quote:Originally posted by Cal Cruzer
Mike, Actually the 225/45 is the closest size to the stock in a 17. Even though the aspect ratio is only 45, it is 45% of the width and since the 225 is much wider, the rolling circumfrence and diameter is almost exactly the same, just marginally shorter. It is a much closer size than a 215/50. I wrote a spreadsheet a couple years ago that does all the calculations and compares different sizes to stock.

True, but I was talking about sidewall height - ground to wheel - and that is only marginally shorter than stock, just under 1/4". This is where the potential negative impact on ride quality can occur (like if you went to those wacky 35 aspect ratio tires), not to mention potentially damaging a wheel due to loss of the "cushion" effect of a taller side wall.

quoteid you put them on stock rims? I have been wanting to use the 225 but am concerned about putting such a wide tire on a 6 inch rim.

No, mine are on Mille Miglia EVO5 wheels, 17x8, so no problems there (you can see them in my sig pic)

[PTGT Redman]

the 225/45 will give you almost identical specs to the 205/50's.
I went 235/45 and i have some speedo error. Plus, the tires are almost 10" wide and ride and road noise suffers. Put on my stock rims with snows, and I feel like i had been driving with the windows open for the last 6 months.
I'd probably go back to a 225 tire on my next set.

225 is a tight fit on a 6" wide rim. 215 would fit and be safer.

[turbomangt]

I think I made the decision to go with good year ls's. They say they will give me better milage than the stock ones, and going to 215/50/17 should be ok in terms of calculation of the speed o. I will say their are way too many choices for tires. Hope I don;t need to go through this again for a couple of years. gary