Goodyear Eagle RS-As, then?
Don’t all tires have wear bars (see the bottom of this page)? These make it easy to tell whether a tire is nearing the end of its tread life.
If it is a Mini Cooper S, you probably have performance tires on there that will wear out quickly.
Tread depth has no impact on grip at all, except in rain or snow. On a dry surface, the only factor affecting grip is the compound, and there is a direct and inverse correlation between stickiness (grip) and wear: the better the grip, the shorter the life. If you want tires that will last you 50,000 miles, don’t expect to be able to take cloverleaf ramps at 80 mph.
The only reason to have tread on tires is to channel water out from the contact patch and prevent hydroplaning. In the dry, tread only weakens grip, because the gaps are areas where the tire is not in contact with the road surface This is why most top racing series use slick tires when the track is dry.
In the situation you are describing, the problem may not have been the tires, per se, but an inappropriate compound for the particular car or your driving style.
NM, misread original post.
I agree with commasense. In road racing and autocrosses, there had been a pattern of teams shaving their tires in order to improve their grip, though today’s performance tires have pretty much done away with the need for that.
But, if tread wear goes even a tiny bit too far, you will lose lots and lots of grip and become a danger to yourself and others on the road. Nothing like discovering how really slippery the white lines painted on the road are because you changed lanes and lost control.
For most drivers, treadwear can also be a sign of old tires. Old rubber generally also has less grip than new. IMO, everyone should inspect their tires regularly to be sure the wear is even and that you don’t need new tires yet.
Now I need to make the appt. to get my snow tires on the car. This thread is a great reminder.
I only got 19,000 miles out of the factory BF Goodrich GeForce T/A’s on my Mustang GT and while they were great on warm, dry pavement, they sucked for every other driving condition, even uneven pavement as the tires would track along with the uneven surfaces and you had to fight that through the steering wheel.
OP, buy a set of these for your car: http://www.consumerreports.org/cro/cars/tires-auto-parts/tires/ultra-high-performance-all-season-tire-ratings/models/overview/cooper-zeon-rs3-a-99043201.htm
They are among the best ultra high-performance all season ties around. I put these on my Mustang and they are awesome. And they are much cheaper than my former ultra high performance summer tires and have double the treadwear. I don’t feel I have sacrificed much, if any, handling on dry surfaces. These are incredibly good tires.
That’s called “tramlining” and AFAIK is a function of the width of the tire as much as anything else. My mustang kind of does it (Pirelli P-Zero tires). But the Viper was the worst one I’ve experienced.