Tire "index" What Is It

[daveloeffler]

This is a new one on me. I know that technology is getting more and more advanced along with the devices and instruments to measure it but what is tire indexing? I took my 94 LS430 w/sport suspension to my local mechanic and they told me that my tire index was over the lexus reccomended threshold, also called Road Force Variation Mesurement. I am currently running Dunlop P245/45R18 96V M+S SYP Sport 5000m tires which I purchased from the lexus dealership last year. The tires have been rotated/balanced every 5K miles. Now this has become an issue. Can anyone help to explain this to me. Thanks so much in advance, Dave

[1990LS400]

I was told that same thing at a Lexus dealership a couple of years ago when they tried to balance my Dunlop Sport 4000 tires attempting to eliminate a severe vibration at 60-65 mph. They said that one of the Dunlop tires was defective and that it had a heavy spot that was so severe that the tires could not be road force balanced.

Funny, I then replaced the Dunlop 4000 all season tires with new Bridgestone directional summer tires but the vibration was still there after they were installed and balanced by the same Lexus dealership. The Lexus dealership then determined that the problem causing the vibration was really worn strut rod bushings. After the two strut rods and bushings were finally replaced (at 86,000 miles), the vibration vanished and the car drove far better.

My favorite Lexus dealer tire guy told me his opinion that road force balancing is overrated and rarely needed. He told me that he rarely road force balances tires unless a customer requests it. I tend to believe him. My snow tires / wheels can be only statically balanced due to the aftermarket wheel design and they don't have even a hint of vibration at highway speeds.

[smooth1]

This is a new one on me. I know that technology is getting more and more advanced along with the devices and instruments to measure it but what is tire indexing? I took my 94 LS430 w/sport suspension to my local mechanic and they told me that my tire index was over the lexus reccomended threshold, also called Road Force Variation Mesurement. I am currently running Dunlop P245/45R18 96V M+S SYP Sport 5000m tires which I purchased from the lexus dealership last year. The tires have been rotated/balanced every 5K miles. Now this has become an issue. Can anyone help to explain this to me. Thanks so much in advance, Dave

Ok, hold up, you took your 94 LS430 to your mechanic........(because why?)

They told you your tire index was over the mfgrs limits......(why?)

The tires you bought last year have how many miles on them now?....... and rotated and balanced by whom?