tires and wheels 13 Inch Revelation

[Kile Brekke]

I've been running the cheap Federal SS 175/60/13s

They are little smaller than stock and probably require a 150 extra RPMS on the freeway, but my car sits much lower than stock and with the dog dish caps I'm liking the look. There is increased gap in the fender wells than with the stock specs which helps a lot with the appearance in my opinion.  

 

You can tell something looks a little sportier, but it doesn't scream at you. 

 

13" wheels just have that refined classic look. I sold the 14" alpina style turbines and I'll never look back. 

[MikeD]

I'm still trying to figure out this relationship. I've bought 165HR13 XAs tires from Summit, off eBay, because their eBay price equals the Coker price, but includes shipping. The tires arrive in Atlanta within a day, and are shipped to me by Coker in Chattanooga! Huh?

Steve

Steve,

Did you mount the XAs' yet?  Did the tires come tube-type or tubeless?  Coker told me that they were tube-type but could be used tubeless.  What did you do?

Thanks,

Mike

[B-Merry]

Much of the discussion on this thread has been focused on rim diameter. The OP reported "The steering is lighter and has gone from heavy and dead to light and communicative. The car rides great, and handling around town seems better. " and it seems to me this was more linked to the transition from 195 to 165, rather than the change in rim diameter. I checked tire rack and they offer a Continental ContiProContact all season in 165/60-15 that fit rims with rim width ranging from 5 - 6.5". So it seems you can run 195s on both 13sand 15s, and you can run 165s on both 13s and 15s. Just curious as to whether anyone here is running 165s on 15" rims?

[Conserv]

Steve,

Did you mount the XAs' yet? Did the tires come tube-type or tubeless? Coker told me that they were tube-type but could be used tubeless. What did you do?

Thanks,

Mike

Mike,

Your short-term memory is worse than mine! You asked this question on August 1st, I answered it, and you thanked me!

http://www.bmw2002faq.com/topic/156487-coker-tires-michelin-xas-165hr13/?hl=xas+tube#entry996088

Give tube-less a shot: maybe on one rim, and see if it loses air. You don't have to mount the rim on the car or balance it; first see if it holds air for a week. If you ask me again in two weeks, I'm going to be pissed!

Good luck,

Steve

Edited August 13, 2014 by Conserv

[Conserv]

Much of the discussion on this thread has been focused on rim diameter. The OP reported "The steering is lighter and has gone from heavy and dead to light and communicative. The car rides great, and handling around town seems better. " and it seems to me this was more linked to the transition from 195 to 165, rather than the change in rim diameter. I checked tire rack and they offer a Continental ContiProContact all season in 165/60-15 that fit rims with rim width ranging from 5 - 6.5". So it seems you can run 195s on both 13sand 15s, and you can run 165s on both 13s and 15s. Just curious as to whether anyone here is running 165s on 15" rims?

I'm going to go way out on a limb and say "No one here is running 165s on 15" rims"! It's just a hunch.

Regards,

Steve

[Swiftus]

What are the two wheel offsets of the the and old wheels?

 

A change in the scrub radius has much more to do with steering effort than the moment of inertia difference.

 

Also, I would bet that for the same package a larger wheel with a smaller sidewall tire has less intertia than the same diameter and width package of the smaller wheel. Rubber is heavy and not stiff, so it needs reenforcement from steel belts in a tire. If you can replace that material with aluminum with a large moment of area, you should end up with a lighter package.

 

F1's tires are horrible. The tires have so much sidewall flex that the mechanical grip of the cars is almost completely determined within the tire rather than within the unsprung system. The low profile tires will force F1 engineers to refocus a bit on mechanical grip by making them not be as lazy as they once were.

[B-Merry]

I'm going to go way out on a limb and say "No one here is running 165s on 15" rims"! It's just a hunch.

Regards,

Steve

I was surprised to see that the tires were even available... But if people like the handling with 165s then 15" rims are actually an option...

Jim

[MikeD]

Mike,

Your short-term memory is worse than mine! You asked this question on August 1st, I answered it, and you thanked me!

http://www.bmw2002faq.com/topic/156487-coker-tires-michelin-xas-165hr13/?hl=xas+tube#entry996088

Give tube-less a shot: maybe on one rim, and see if it loses air. You don't have to mount the rim on the car or balance it; first see if it holds air for a week. If you ask me again in two weeks, I'm going to be pissed!

Good luck,

Steve

Steve...your right...my short term memory is bad....after I asked you i searched and found your first reply...was going to let you know that but you beat me to it   Thanks again.

[Conserv]

Steve...your right...my short term memory is bad....after I asked you i searched and found your first reply...was going to let you know that but you beat me to it   Thanks again.

No problem, Mike!

And please let us know whether the tube-type XAs tires work without tubes!

Regards,

Steve

[bob02]

Here are my observations on wheels and tires:

 

Weight is a critical factor. The lightest i could do in 15" was Weds Bavarias with Dunlop star spec 195/50/15. 31.5 pounds. Handling is great, but the car still had that lethargic feedback feel.

 

 Next is the setup currently on the car: Cromodora cd40 with Toyo proxes 205/60/13. 28 pounds. The lightness and snap are back, feedback is excellent. Loss of grip over the Dunlops? None. Maybe a little sidewall flex, but i could care less. I love this setup.

 

  Last, E30 basketweaves with Falken Ziex 195/60/14. Boring. Pedestrian. Weight didn't matter, they were boring.

 

    I realize not all folks care(obsess) about the weight of the tire/wheel combo, but i think it's critical to how the car feels. To each their own!

 

 Long live the 13"!!!

[Conserv]

Here are my observations on wheels and tires:

Weight is a critical factor. The lightest i could do in 15" was Weds Bavarias with Dunlop star spec 195/50/15. 31.5 pounds. Handling is great, but the car still had that lethargic feedback feel.

Next is the setup currently on the car: Cromodora cd40 with Toyo proxes 205/60/13. 28 pounds. The lightness and snap are back, feedback is excellent. Loss of grip over the Dunlops? None. Maybe a little sidewall flex, but i could care less. I love this setup.

Last, E30 basketweaves with Falken Ziex 195/60/14. Boring. Pedestrian. Weight didn't matter, they were boring.

I realize not all folks care(obsess) about the weight of the tire/wheel combo, but i think it's critical to how the car feels. To each their own!

Long live the 13"!!!

OK, Bob,

A Campagnolo Ragno in the 5.5x13 size is 10 lbs., 1 oz. But with a 165HR13 XAs mounted, the combo is exactly 30 lbs. I can't imagine the Cromodora, which should also be magnesium alloy, weighs much less than the Campy, so the Toyo is appreciably (~2 lbs.) lighter than the XAs.

Interesting.

Regards,

Steve

Edited August 13, 2014 by Conserv

[jrkoupe]

I say long live the 13 as well....

oe 165...or 185/70 .....or 205 60.....just feels right on these cars....for a street car ....

....now for a track beast ,its a whole 'nother story.

[Andy74tii]

Regarding the weight of Cromodoras, I can say that mine (CD32, not CD40) at size 5.5 x 13, weigh around 8.5 lbs. They are considerably lighter than anything I've had, and that weight loss does seem to make a difference....

[Conserv]

Regarding the weight of Cromodoras, I can say that mine (CD32, not CD40) at size 5.5 x 13, weigh around 8.5 lbs....

Wow: that is a LIGHT rim!

Steve

Edited August 14, 2014 by Conserv

[Slavs]

I'm one of the 13" diehards. When the large diameter wheel with very low profile tire combination trend started I refused to jump on the bandwagon. Weight is critical, especially un-sprung weight. A larger diameter wheel will add a lot of weight. And, that's not good. IT's a completely different feel. Modern cars are much heavier compared to some of the European classics. The heavier wheels work OK with the heavy cars, but it is counterproductive to use them on a light car.

 

When you buy a Mazda MIata or a MIni, you're not buying a light car. These things are much heavier compared to their classic counterparts such as the Lotus Elan and the MInicooper.

 

Due to the new heavy trend, it has become much harder to obtain good 13" rubber. I run the  205/60/13 on 5.5" rims. The 205/60/13s are nearly impossible to find unless you buy racing rubber. There are a couple of Chinese brands available in touring tires. I've tried the same wheels with the 175/70/13 tires. This latter combo was much snappier and seems a better fit for this diameter wheel. The 205/60/13s though are smoother. The 175/70/13 are abundant.

 

The 205/60/13 and 175/70/13 have the same overall diameter and sidewall height, which is about an inch shorter than stock and which will affect your gearing by about 3%. So if your final drive is 4.11, this wheel / tire combo will effectively reduce your gearing to about 4.23. It will also effectively turn your 3.64 into a 3.75. Your top speed will be reduced by 3%. And your mileage will also be reduced by 3%. 22mpg become 21.3mpg.

 

The 185/70/13 is probably the best tire size. The overall  diameter is nearly the same as the stock 165/80/13, and your  gearing won't change either. There are plenty tire manufacturers producing this size, but the real high quality and high performance brands are getting sparse.

 

Slavs