Long Term Kuhmo ECSTA 712 Test Report

I ordered a set from Tire Rack at the end of May 2000 right as they
first started shipping. $109 a pop was a little too hard to pass up. If
they turned out awful, I'd beat the crap out of them and replace them
quickly and only be out $450. I've probably put 15k miles on them now.

First a little background:
I have 97 M3/2. I've added: UUC Strut brace up front, Dinan rear brace,
X-Brace underneath, UUC Swaybarbarians - middle setting up front, full
soft rear, camber correction bolts to give me -1.7 deg. camber up front
(tried the swapped strut mounts with -2.2 deg. camber which caused way
too much inside tire wear), JC Intake and SW. Dedicated track wheels and
R-Compound tires so street tires don't see the track.

I have had the following tires on the car:
- Michelin MXX3 Pilots - original tires on stock wheels. Got 12k miles
- Yokohama AVS-S1s - 245/40-17s rear 235/40-17s front on stock wheels.
Got 25k miles
- Yokohama AVS-Sports - 245/40-17s all around on 17x8 wheels. Swapped
front strut mounts around 16k miles - got 21k miles before inside wear
got too much and had to replace them.
- Kuhmo ECSTA Supra 712s - 245/40 all around. Changed strut mounts back
to stock and added camber bolts. Added UUC Swaybarbarians at the same
time. Car now has >74k miles.

Impressions:
Pretty nice ride. The tire isn't as wide as the AVS-Sport in the same
size - looks more like a 235/40-17 sized tire. Does everything well for
even spirited driving. At the limit, they definitely lack in ultimate
grip compared to the AVS-Sports or MXX3s.

They took a LONG time to wear in. I was pretty disappointed for the
first few hundred miles (800-900) since I expected it to take 100-200
miles for them to stop feeling greasy at the limit. The seem to get
better with age.

In the wet, they are pretty darn impressive. During the last rainstorm,
I was able to drive 60-65 in moderate to heavy rain and the car felt
sure-footed. Definitely better than the MXX3's and the AVS S1s and even
better than the AVS-Sports at the same mileage (12k miles).

I've driven these on the usual city streets and highways around SF Bay.
Highway 17 from San Jose to Santa Cruz is no problem but I don't push it
to the limit there - too many cops and unpredictable idiots. I routinely
drive Highway 9 from Saratoga to Ben Lomond (where I live) and I do push
the limit there. The Kuhmos acquit themselves admirably. Their limit is
definitely not as high as the MXX3's or AVS-Sports but it actually helps
you develop better skills.

They seem to grip better at 30 PSI all around but I have run them at 36
PSI which definitely yields better gas mileage. But even then, the
AVS-S1s are tops in this category.

Tire wear seems to be a little higher than the AVS's but it's pretty
even. I'll probably get about 20-21k miles on these, but I am also
trying real hard to beat on them.

I have to admit that for 90% of the typical driving you'll do day to
day, these are a stone cold bargain. For those that want better
performance and still save some money over the S-O2s or Pilot Sports,
I'd highly recommend the AVS-Sports for all around performance wet and
dry. If I wanted a dedicated rainy season tire, I'd go with the Kuhmos
in a second. If I wanted a decent day to day tire that won't see any
mountain roads or get pushed to the limit every day, I'd go with the
Kuhmo's. There'd be enough money left over to almost pay for a set of
R-Compounds for the track.

Bob Lenarcik 
lenarcik@pacbell.net