Tires

Kumho Ecsta Supra 712

Well, I have a couple weeks and about 2000 miles on the new Kumhos.

My initial reaction is WOW! Wierd tire design for the street. Built like a race tire with a real
soft tread construction and STIFFFFFFFF sidewall layers. The compound used is sticky but
not soft and the Tread wear is rated at 280 (we'll see how they wear). They are quiter than any
tire I have ever run and the Old Buggers transmit road noise to the cabin much more than the
newer cars so that's important. The quiet running extends all the way to the traction limit until
the onset of breakaway where there is a slight scrub and then a small squeal in some
conditions. For the last couple days I have finally had a chance to experiment with wet grip
and they are amazing. I chose these tires over the RE730 because I thought the tread design
was more advanced and the reviews and comments I heard were pointing to a tire that didn't
give up as much dry traction to get longer life. Also, because of the sizes available specifically
225/40 and 225/45 and 225/50 for 16".

The wierdest part is the tire pressures I am running cold. I have run 40 front and 36 rear in my
RE71 for a season and a half and 40 in all corners with the old phone dials and D40s. That was
after much experimenting. With these new tires I started at 38 front and 36 rear mainly because
I have a 5% lower profile in the front this time. The car was unmanageable and the rear was
loose. I pulled the car up in my garage and could see the problem immediately. I was only
using about 2/3 of the contact patch in the rear. So I started letting air out and ripping down
the 4 miles of corners in my favorite canyon. I chalked the sidewalls as I went and let out air in
a couple of pound increments. In the end I had 32 front and 30 rear. I have been flogging the
car pretty hard and it seems to be running and handling perfectly. The tires are not rolling over
at these pressures and the old palm pyrometer is telling me that the center of the contact
patch is anchored.

So here's the deal: They are just awesome and they are dirt cheap. If they wear like they are
rated to wear I may put them on my Audi next summer. They are available in all kinds of sizes
and profiles too so they seem to be tailoring them to the tweeker. BTW I am running 225/45
ZR16 W63 on 16 x 7.5 and 245/45 ZR16 W89 on 16 x 9 Design 90 wheels. It's just a different car
now!

Jay Kempf
79 US 5 speed