15's or 17's

[RedLight_Si]

How much of difference performance wise(cornering,stability and such) is there by going with a 17" wheel without lowering? Im thinking about going with a lightweight 15 x 6.5"-7" wheel with some good tires. On the other hand I could go with a not so light 17" x 7"-7.5" wheel with good tires. Would I be able to compensate by going with a wider tire(205 or 215) on the 15's. Suggestions.....

[BarracksSi]

The general rule is that bigger rims will slow you down. Even if you find 17's that are the same weight as equivalent 15's, the fact that more of the mass is pushed to the perimeter means that the rotational inertia is higher, which translates to slower acceleration.

17's will allow you to run much bigger brakes and can sharpen turn-in response. But, they're likely going to be heavier, ride more harshly, and be more susceptible to road damage.

[VividDreams]

^^^what he said

if you find a good set of 15's, i.e. Bridgestone Potenza S-03 Pole Position, Falken Azenis, or some others, youll hang with, or handle better than the guys runnin 17's

[BSEVEER]

If you go with 15's you will need to go with a 50 series tire to get good cornering properties. 50 series tires on 15's will look too small and throw your speedometer way off.

[RedLight_Si]

Thank you for the input so far. The Falkens sound like they are good and I have heard nothing but good things about the Bridgestones,but the Bridgestones seem to be a bit on the heavy side(around 23 lbs for a 15").Is the extra weight of these tires worth it? Wont the heavy tires just cancel out the benefits of the lightweight wheel?

[RedLight_Si]

It seems either a 205/55,215/55,or 225/50 size tire would keep me closest to the stock diameter. The 205/55 seems to be a good size,but the 225/50 might perform better. How wide of a wheel would best suit tires this wide?

[trabadoo22]

My opinion is that a fairly light 17" rim/tire combo will give you much more performance than a 15" rim/tire combo if you are talking about handling. If you were going to get anywhere near the performance of the 17's the tires would have to be low profile and wide. This sucks for two reasons; the low profile 15" tires will make the already apparent wheel gap more apparent, and a wider tire on 15" rims is going to have more sidewall flex because of the rim width. So my vote goes for 17

[VividDreams]

[QUOTE]Originally posted by trabadoo22
[B]and a wider tire on 15" rims is going to have more sidewall flex because of the rim width....I wish I would have gotten 17

[trabadoo22]

It looks like you are right. Sorry about the confusion, I was just under the impression that a wider tire on a smaller rim would cause more flex.

[EP3.. 2.. 1 GO]

17's might slow you down when you will be accelerating at the beginnig but later when you get to higher speed they will get you more speed than 15's. All depends what you want to do?? But my vote go to 17's !!!!

[BarracksSi]

Originally posted by EP3.. 2.. 1 GO
17's might slow you down when you will be accelerating at the beginnig but later when you get to higher speed they will get you more speed than 15's.

They will if you also get tires with a bigger circumference than stock. For that matter, you could probably find tires to fit a 15" rim but have a notably bigger circumference, but they'll start to look like balloons.

If you get a tire size for 17's that doesn't throw off the speedometer, then they've got the same outer diameter & circumference as stock, and therefore won't give you a faster top speed.

Go to http://www.miata.net/garage/tirecalc.html and plug in 195/60-15 for stock, and 225/55-17 for new. 10% error, they'll look silly, but you'll go faster at the very top. Then, change the new dimensions to 225/40-17, and you'll get a speedo error of 0.5%.

Basic rule: rim size does not automatically mean that the speedometer will be off, or that speed will be increased.

[BarracksSi]

Adding on --

Using that tire size calculator (should be in every car enthusiast's bookmarks), a 225/65-15 tire will be very close in circumference to the hypothetical oversized 17" that I mentioned above.

Problem is, it would look better on a Caprice cop car than a Honda... lol

[VividDreams]

Originally posted by BarracksSi
Go to http://www.miata.net/garage/tirecalc.html

oooor, you could give him the one on 7thGen... you ALL should be members THERE as well... he he

heres the link--->http://www.7thgencivic.com/modules.php?s=&op=modload&name=Tire_Calculator&file=index

it even has an explanation at the bottom:cool: :D