So just last week, I decided to try a wide 15" tire on my 15" R81 Imola Holies. I had a set of Toyo Proxes Four 205/55/15 installed (the original size spec is 175/65/15).

Even though it only adds 4.5 pounds per corner, the ride had gotten less nimble; more numb. I assume some of this is due to the larger contact patch as well as the weight. The original wheel combo with the Contis was 15.5 pounds/wheel, the new setup is 19.8 per corner.

I'm considering taking them back on the retailer 30 day test-ride guarantee. I'm a little hesitant to do that as it was my choice to stray so far from stock size. Also, I hate to think of these tires being trashed instead of reused (not sure what'd happen to them).

I know I'm just kinds thinking out loud here and it's a decision I'll have to make myself. I just though I'd put it out there to see what others might have to say, or even better, what your experiences of a similar change has been.

Thanks

 

Have you taken any hard turns to see if you are getting better grip? You also increased the diameter by over 11% from stock, which will screw with the speedometer and ride quality. I would consider getting wider wheels like a 7 or 7.5 and keeping those tires.

http://www.1010tires.com/TireSizeCal...?action=submit

 

The 205/55/15's are the closest thing to stock. The diameter isn't 11% different, it's 0.333%. (moving 60.2 mph when the speedo says 60). Maybe you entered the numbers wrong in the calculator?

In hard turns, it feel more numb; and it's hard to say it feels more stable as it never felt unstable with the stock Contis. Where the wider tires may have an advantage is in high-speed cornering. These smooth, winding rural roads here in central new England can be a blast when taken calmly at 90+mph. In these situations the wider tires seem to provide a slightly more stable platform.

I'm hesitant to go with wider 15" rims. Mostly becasue I can't see prioritizing money for such a change. I'd also be concerned that a wider rim would add even more weight per wheel. (The R81Imolas are quite light at 12 pounds each).

I think the best/most economical way to get the playfulness back would be simply to go back to the stock tire size.

hmmmm........

EDIT TO ADD:

I see the Konig FlatOut 15x8 you were looking at are also only 12 pounds. that's pretty tempting; but still, $400+ I don't really want to spend.

 

As an R50 owner with the stock size tires (Conti ProContacts) and the Holey wheels I would advise going back to that combo. They aren't the quietest tire you will ever own but they look great on those wheels and seem to grip in the corners like nothing else. I regularly toss my R50 through a highway construction detour road at 60+ with s-curve speed limits set at 25 and the rest at 40. Maybe it's just because I'm usually late for work.

Go back to the stock size. You've got a beautiful car- Velvet Red with a white top and wheels will look even better with the stock tires.

Val

 

Thanks.

And I think I might have to go back to the stock tires. --it just seems so wasteful (I feel like a minor idiot too FWIW)

Anyone have any idea what'd happen to these Toyos if i gave them back?

 

They'll probably sell them as used. I doubt they'd just be thrown out.

I like the look of those white Konigs. I've been thinking about going to 15" when I wear out my current tires.

 

I've got 195/60/R15 tires on my holies, and like them very much..

 

It's a myth that wider tires have a larger contact patch than narrow tires. Wider tires just have a shorter, wider contact patch. Skinny tires have a long, narrow contact patch. All else being equal. There are advantages and disadvantages to each. See...

http://autospeed.com/cms/title_Tyres...5/article.html
http://www.performancesimulations.co...on-tires-1.htm
Also The New Mini Performance Handbook by Jeffrey Zurschmeide , I forget the page number.

 

By "less nimble; more numb" handling, it sounds like the wider tires might have been more reluctant to change directions; they don't provide the initial turn-in sharpness of the OE size tires. The wider tires may provide more lateral grip once in a stable cornering state, but the transitions are not as sharp (nimbleness?).

 

When using the stock 15x5.5" wheels you have a very light 12 lb rim.

Possible size tires to use with about 24.3" tire diameter as a goal for good odometer and speedometer accuracy for street use:

175/65-15 In this size tire selection is rather limited for best handling-
see
http://www.tirerack.com/tires/tires....omCompare1=yes
Yokohama AVID ENVigor High Performance All Season tire
$88 each 560 treadwear, H speed rated, 18 lbs each

185/65-15
195/60-15
205/55-15
in this size for a blend of handling and longer treadwear in various weather conditions-
http://www.tirerack.com/tires/tires....5E4X&tab=Sizes
Kumho Ecsta 4X Ultra HP All Season tire
$80 each 420 treadwear, V speed rated 19 lbs

This tire is in the same class as the Toyo Proxes 4- UHP All season

In general any of these tire sizes can be used with the stock 15" wheels but the wider the tire the lower the sidewall and the less the tire flexes. Handling will be a little better with the lower sidewalls but ride roughness will increase. The Proxes 4 is more of a street tire with softer sidewalls, if you want better handling you can try an UHP summer tire with a stiffer sidewall construction.

Stock tires aren't very good, they do offer low weight for fast straightline speed but not very good cornering and not good braking. I did manage better mpg than when using wide tires.

 

I can relate to what you are saying as today I just swapped out my 195/50R15 Michelin X-Ice on Holies, for my 215/50R16 Falken 912ZEs on Konig Feathers (15lbs.)...

I agree it feels much less nimble/agile on turns, BUY I disagree with stability - my 2012 Base Cooper feels ROCK solid (could be the change from the squishy winter tires?).

Maybe you want to stick with them for a few more days and give them a couple of really hard runs?

BTW, on my 2007 "S" I felt a lot of torque steer with hard starts, obviously no hards starts possible with Base Cooper

 

i think this video says it all ...
http://www.youtube.com/watch?v=HPh90yNX-mY

been riding on stock 175's for a lot of years myself as they are my faves (been through all types of sizes on 16's and 17's before)

that being said 205 on the stock wheel I think is too wide. I would try the 195's.

 

Lurch70, Can you elaborate a little more on why you think 205 on stock is too wide? I am in the same boat with 175s on 15 spoolers and I understand the advantage of lightweight wheels but don’t like the bicycle tire look of the 175s. My plan is to go with the Kumho Ecsta 4X 205/55/15 tires. They are Ultra High Performance and lightweight at 19 pounds. The comparable Kumho Ecsta ASX 195/60/15 is also Ultra High Performance and lightweight at 19 pounds so no gain in performance due to less weight. If anything the 195 is +0.25 larger in diameter than stock 175s and may seem less quick off the line than the 205, which is -0.08 from stock or -0.33 from the 195s.

 

205s do fit ok on the stock 15x5.5 wheels, but 5.5" is not the best width to match that wide a tire,
so it softens the advantage of going to the wider tire. They'll do better on 6.5 or 7 inch rims.

 

That is what I was thinking; the fit for a 5.5” wheel is a better match for 195. I’d like to go with a wider rim but now we are talking more weight and that is working against performance especially on the straight cooper.

 

Unless you go for something really nice and strong and forged like a Volk TE-37 (8.8# 15x6.5, 9.15# 15x7)
or SSR-C (8.6# 15x6.5, 9.3# 15x7) or BBS RG-F (10.2# 15x7).
Much cheaper, but not as strong in cast wheels you have Kosei K4r, Kosei K1, OZ Ultralegerra, and Enkei Racing PF01
all 11 to 12 pounds in 15x7.

 

OP here.

So, I've put a couple thousand miles on them (it's been a month...I drive a lot) and the 205's have really grown on me. True, I've lost some of the nimbleness of lighter tires, but their combination of additional structural material as well as tread width gives the car greater high speed stability and an all-around more cushy ride. But without feeling at all "squishy" like my Q-rated winter tires.

If I had to do it over again, I would probably split the difference and go with a 195 or-so.

But I am really enjoying these 205's I've even come to like the way they look--not so much like the clown shoes I thought they were at first.

Here are some pictures of them on my car that i have posted in another thread here at NAM.

(I took them w/ my phone so forgive the quality)

 

How much have they affected your mpg?

 

For the first tank, It looked like it had improved by 1 or 2 mpg, but now with more miles to calculate, it seems unchanged.

(Compared to the mileage I got this time last year w/the Contis, coming off the winter gas blends)

 

I have run many size tires on the stock 15" wheel and the stock size is definitely the best mpg by about 2 mpg. Be sure to keep tire pressure up slightly on the high side about 38 psi cold is OK.

Worst mpg is with stock 17x7 wheels and 205/45-17 tires event with higher psi. Too much rolling resistance.