Correct tire size question

[Burg Boxster]

Originally Posted by KRAM36

I agree his statement was overboard, however if it was my car I would go with 265/35/18 tires to better match the rotation speed of the front tires and make the car feel less twitchy and yes most all tire manufacturers make that tire size. Also the circumference difference between the the 35 and 40 series is a 3.9% smaller circumference for the 35 series. So he would get a bit quicker acceleration and stiffer sidewall for better handling, but will ride just a bit rougher.

To which front tire size - current actual or should be?

I highly doubt wrs986's IMSA or F1 career is in jeopardy b/c of size variances in the tires he has vs what should be there. Nor his Spec B career (well mostly b/c he'd be in violation running 18" ). Not to mention he's wearing matching shoes w/ tread on them which candidly is better than probably half the vehicles on road... and 99.9% better than every Kia or Hyundai I see traveling 95MPH+ in the rain - LOL

Would I consider correct sizes when replacing tires...probably, but it's not imperative b/c he really is close enough. You're talking about an overall ~ 2.9% variance delta b/w recommended size circumference vs what's actually on there (it's 3.8% F/R w/ what on their vs .9% F/R for recommended). Yes, I know that size should be available. Who knows though, maybe Tire Kingdom or whomever was out of stock on them the week the previous owner needed new rubber.

So yes, your mathematics are correct on the rotational speed of the tires. Precision is one thing... accuracy another. Think wrs, me or you would notice? Heck, I'll buy you steak dinner (or tofu if that's your protein) w/ all the trimmings if you could prove to me w/ even 50% accuracy using only your "buttometer" which tire size was on any vehicle w/ variances to this level.

Bottom line, wrs986 came here to make sure what he has works. It does... and well too! Let's encourage him to not fret over this non-issue but instead to get out there and enjoy his new ride w/ those great looking wheels and see what these cars are all about and truly capable of. That's what this should be all about.

Good luck

[KRAM36]

Originally Posted by Burg Boxster

To which front tire size - current actual or should be? )

The current actual front tires on the car.

Originally Posted by Burg Boxster

So yes, your mathematics are correct on the rotational speed of the tires. Precision is one thing... accuracy another. Think wrs, me or you would notice? Heck, I'll buy you steak dinner (or tofu if that's your protein) w/ all the trimmings if you could prove to me w/ even 50% accuracy using only your "buttometer" which tire size was on any vehicle w/ variances to this level.

You owe me a steak dinner then. When I have to go from Summer to Winter tires I can tell a big difference in the twitchyness of the car. The front tires are smaller in circumference and turn in very quickly and the rear tires turning at a slower rate are trying to catch up. I absolutely hate the front tires spinning faster then the rear tires, especially in a mid engine car and I can tell the difference, very unbalanced.

This is what he is having to deal with when he could have the above mentioned nearly identical rotation speed and have a much more pleasant handling experience.

Originally Posted by Burg Boxster

Bottom line, wrs986 came here to make sure what he has works. It does... and well too! Let's encourage him to not fret over this non-issue but instead to get out there and enjoy his new ride w/ those great looking wheels and see what these cars are all about and truly capable of. That's what this should be all about.

Yes his setup works, not optimal, not even as close to factory level of rotation speed difference (if that's the correct tire size Tire Rack and tonythetiger said to go with), but works well enough for him I guess. I'm hope his tire combination will give him plenty of joy, but he is asking questions about his tires so we could be assuming his happiness level wrongly.

I just said if it was my car, what I would do with it, which would be cheaper then what tonythetiger suggested for him to do and balance out the car better.

.........................My Summer tire setup........................................My Winter tire setup.



It's like I'm driving a different car. Yes someone swiped the original Carrera Light 18" wheels off the car at some point, probably one of the dealerships it was at.
I'm the 4th owner of the car.