Kuhmo Tire Questions
Thread Starter
Instructor
Joined: Mar 2001
Posts: 230
Likes: 1
From: Phila. Pa.
Kuhmo Tire Questions
Will be buying a set of Kuhmos for my '86 along with some 17 inch ZR1 wheels (9.5 inch all around). I don't use the car in snow but I do use it in rain. Should I go with the MX or the Ecsta 712. I was also thinking of going with 285 40 17 rather than 275 40 17. Will there be any rubbing issues? They are just a little bit larger. Any and all advice welcome. Thanks! Cruz 86
Team Owner
Joined: Sep 2001
Posts: 62,161
Likes: 1,733
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Get the 712s, thats what I have, and I have to drive in rain alot.
MX is a better dry tire.
If you got wheels with the right offset, there will not be a rubbing problem.
MX is a better dry tire.
If you got wheels with the right offset, there will not be a rubbing problem.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
The MX is an excellent dry weather tire and will work in the rain, and I have even run a couple autocross events in the rain with my MX tires and had no real problems as long as I was careful when applying power. But I'm not too sure about doing high-speed events on them.
For the money, you can't beat the MX tire. There are other tires out there that will outperform them in the wet but they cost nearly twice as much.
For the money, you can't beat the MX tire. There are other tires out there that will outperform them in the wet but they cost nearly twice as much.
Race Director
Joined: Dec 2002
Posts: 13,348
Likes: 233
From: SCMR Rat Pack'r Charter Member..Great Bend KS
The 285 is less than 1/2" wider than the 275, so don't let that worry you.
The MX works fine in the rain (I have them on my Vette), but the 712 works better. It's all a compromise and only you can decide which is best for you.
Larry
code5coupe
The MX works fine in the rain (I have them on my Vette), but the 712 works better. It's all a compromise and only you can decide which is best for you.
Larry
code5coupe
Race Director
Joined: Sep 2001
Posts: 14,682
Likes: 753
From: NEwhere Ohio
Another issue I failed to discuss with the Kumho Ecsta MX is that it doesnt have as many layers of spiral overlays and is a single=ply tire.
While reduced sidewall/shoulder stiffness is beneficial for drag-style launches, hi-speed steering response may not be as razor-sharp as say a Michelin or Goodyear with 2 plys and 2 nylon overlays. This information is marked on the sidewall.
Surprisingly, the Kumho Ecsta Supra 712 has the 2 ply, 2 overlay construction, while its more expensive Ecsta MX counterpart doesnt.
Keep in mind also that both Kumho Ectsa Supra 712 and Ecsta MX have skimped on the silica content. They are only giving you 18 parts silica vs. most other UHP's tire 30-50 parts silica filler. So they wont be as good in the wet. In the dry, there will be no difference.
While reduced sidewall/shoulder stiffness is beneficial for drag-style launches, hi-speed steering response may not be as razor-sharp as say a Michelin or Goodyear with 2 plys and 2 nylon overlays. This information is marked on the sidewall.
Surprisingly, the Kumho Ecsta Supra 712 has the 2 ply, 2 overlay construction, while its more expensive Ecsta MX counterpart doesnt.
Keep in mind also that both Kumho Ectsa Supra 712 and Ecsta MX have skimped on the silica content. They are only giving you 18 parts silica vs. most other UHP's tire 30-50 parts silica filler. So they wont be as good in the wet. In the dry, there will be no difference.
Race Director
Joined: Jun 2001
Posts: 10,956
Likes: 681
From: Marlboro country MA
I had a set of 712's for a couple of years. For the money, they were great tires. After over 35,000 miles, they still had a third of the tread remaining. Although they were fine in the rain, they weren't so hot in snow, so I replaced them with Pirelli PZero Nero's. At the track, I consistently got 60' times under 1.95 sec, and once got a 1.882.
Racer
Joined: Nov 2000
Posts: 351
Likes: 0
From: Allen TX
I have the 712's now and would give them a 6 out of a possible 10. My previous tires were Firestone Firehawks and they had much better traction from a standstill than the 712's. I can spin the rears too easily with the 712's so it's like learning to launch again. I don't notice any difference in cornering between the two. I do know the 712's are a relatively heavy tire 
Next time I buy tires, I'll probably look for something better, but these fit the budget at the time.
Next time I buy tires, I'll probably look for something better, but these fit the budget at the time.
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Le Mans Master
Joined: Dec 2004
Posts: 5,789
Likes: 8
From: Myrtle Beach SC
St. Jude Donor '05-'06
If you go to tirerack.com you can view user feed back on tires and the set I chose was the Ecsta ASX tire life rating 400 and rank 8th of all the tires they sell so they must be liked by someone other than me.
