Thoughts about mixing 2 types of tires (front/rear)-

These are NOT my everyday tires - These are practice tires which go on an extra set of wheels - purely for AutoX, Skidpad, Slalom, etc.

The obvious answer is "not to" but finding matching sets of practice tires is tough.

1. Front - Michelin PS2 - Full Tread
2. Rear - Pirelli P0's - Full Tread

I purposefully DO NOT want slicks or comps- I want street tires to push and learn the limits of street tires in street application.

I would love to hear from very experienced drivers & instructors (qualify your experience?)

 

Simple. Never mix tires. You won't learn anything about your car with improper tires on it.

 

Yes, like I said that is the obvious answer....but why not? Both of these are high performace street tires - hardly "improper tires" for this car. Both PS2's and P0's have similar rubber compound and similar tread pattern. This is purely for practice, shredding them up, pushing past limits.... So I'm asking....why not? I am challenging someone with good knowledge to give me some good reasons and explanations here.

 

It's been covered many times. Search the forum. There is much information herein. Bottom line is that each model has different compounds with different qualities that don't mix well. Then, do whatever you like. If someone tells you not to stick a fork in an electrical outlet and you choose to do so to experiment.... Your car, your consequences.

 

Mix your ties...run them down to the cords...and get back to us with your experience. It's your car and your life and as you don't live near me, your decision will not affect me. It will add another data point on the Darwinian scale of evolution.

 

OK.......here's my thoughts on your endeavor.

I'm a retired mechanical engineer with 36 years at the big yellow tractor company. 16 of those years was spent in vehicle design and development. The first irrefutable rule of testing and development is that you simulate the intended use conditions in the testing program. Anything you do the stray from this axiom will only lead you to false or incorrect conclusions. In doing so, you lose ground towards learning how your design will fare under the conditions of its intended use.

Now, you can take short cuts, as you propose, only if they have no affect on the particular area of the vehicle you are trying to test. If your intention was to test ****pit ergonomics, the exact nature of the engine lubrication system would probably have no affect on your testing. You could test with something less than the production lube system.

However, if you are trying to test and learn how the vehicle handles and reacts in a dynamic handling environment, testing in anything other than the configuration to be used in the competition would be worse than useless. It would provide you false information as to how the car will handle in its intended competitive configuration. Trust me, bad data is far worse than no data. To conduct handling evaluations in order to learn while using a compromised tire set up will provide your with false feedback and you will draw incorrect conclusions as to how the car will react with the correct tires.

The tire is the single most important link in the chain of vehicles handling and dynamic response. It's the only thin that holds the car to the track. What you will "learn" is of dubious value. I cannot stress strongly enough that bad data is WORSE than no data! Add to this the possibility of compromised or loss of car control, and you can create a situation of an accident looking for a place to happen.

What are you expecting to learn from your test plan?