I won't sound bad to readers and I frankly doesn't mean that somehow "badful" and I do not try to sale my P7's for what ever high price. I assuming that I have much easier ways to advertise my "left overs". The discussion's about those tire matters started with a simple question from another member and I just tried to help out. Somehow it went another route and my answers to some other responses on the board turning out to be misunderstood or I did explain it the wrong way. However I just liked to give some personal expiriences to the followed up messages.
Most "civilized" countries have the rules, that certain cars can't have installed certain speed-rated tires or in other words, there is common sense, that "fast" cars shouldn't have installed "slow" rated tires, without regard to the countries speed limits. At this point I like to mention, that some of us enjoying to go on a race track here and than and we do still have the same "street"-tires on the car. To judge on the appropriate ratings, it must been mentioned, that all the so called tested ratings are resulting from the manufacturers test bench, which is combined with the idealst environment, like ideal ground temperature, ambient temp and pressure measured at sea level (15�C), brand new tire, optimum tire pressure, and last no different weight loads, as we do have while driving the vehicle.
One member wrote, that he weighted many Panteras in the past. I do believe him, but the gross weight is not the point behind the weight ratio of a tire. There is a lot of differences, when the car is loaded with heavy persons, there may be some luggage or spare parts, etc. Let's say, the gross weight reaches 3000 lbs. The tire installed has max. load-index of 3500 lbs. The tire pressure is ideal, the roads are just perfect, the temperature / humidity and outside air pressure is perfect as they were while the same tire were on the test bench. Let's go driving and keep going with 70 MpH. There is a right hand corner which can be approached with the same speed. During the turn, the driver accelerates. The overall weight stays the same, but the PRESSURE weight shifts to the left rear suspension. Some shock load will be equalized by the shock absorber but the main PRESSURE weight will be carried finally from the rear left tire. Thats the point where the load index becomes important. And Steve is correct, when he's saying, that it depends how someone operates the vehicle. Thats exactly what I've said before, not the speed limits are the point, but the operation of the car with the appropriate tires. Not only the gross weight is question, but the pressure load which shifts from one axle to the other, from one side to another, etc. There are mathematical formulas to use, depending on arm, weight and moment. Hopefully nobody feels that I would make some "commercial" for selling my P-7's, but I certainly are concerned for folks who have the wrong advise. Sometimes there is a bit more than only the very visual point. I do understand, that there is a problem with finding the correct 15"-tires. But again, before anybody is going to install "under-rated" tires, they better are going for the proper 16"- or 17"-rim-sets, which most Pantera parts supplier or main tire shops can offer. Its finally less cost and safer, than having an accident with the result of a damaged car or even worse.
[This message has been edited by Fritz (edited 04-29-2001).]
[This message has been edited by Fritz (edited 04-29-2001).]