Tires: Mixing diff load ratings, emergency maneuvers, utqg ratings

Question
QUESTION: My car takes a 95 load rating.  I have the opportunity to get a good deal on the exact brand and size except the load rating would be a 97.  Can I have 3 tires with a 95 rating and a 4th with a 97 rating on the car at the same time. Would this adversely affect handling?

ANSWER: Steve,

There is usually some additional difference if there is a load range difference.

The Rule:

It is best for all 4 tires to be exactly the same - size, brand, model, and state of wear - or at the very least, the same on each axle with the best tires on the rear.

The reason for the rule is that in emergency maneuvers, vehicle tend to pivot around the odd tire - just when you don't what that to happen.

So if you can't follow the rule, then it is next best to get as close as possible.  It sounds like you are pretty close, but you need to figure out what else is different.

---------- FOLLOW-UP ----------

QUESTION: Here is my follow-up question  
In my case the tires would be exactly the same size manufact. and tread pattern. Two of the tires are brand new and two will have 75% tread left. The odd tire, the 97 has a load rating of about 50 pounds higher than the others. Maybe a stiffer sidewall?  

These are high end Michelins going on a BMW used by a salesman mostly for highway driving .

Thanks

Steve  

Answer
Steve,

You didn't supply more details, but I'll bet the difference is between a tire with a "P" in front of the size and one without a "P".

But even in those cases, there has to be a reason why they did that.  Usually they stay with one or the other.

The most likely explanation is that one of these was an OE tire and one is a replacement market tire - and if that is the case, the odd tire is probably sufficiently different that it would be unwise to use as a single tire in a set of 4.

One way to check to see if there is a sufficient difference is to look at the UTQG ratings.  Any difference would be a clue.