Tires and ride improvement

[zafarhayatkhan]

I had Dunlop Sport A2 205/60 tires and was not satisfied with road noise and ride.

I reduced the tire pressure and that helped the ride but increased tire wear to a point were after 12K miles, they were deformed to where they sounded like a bearing had gone bad! The Dunlops probably had a manufacturing defect.

Replaced them with Goodyear Eagle GT 215/65 tires and now it rides like a totally different car. Road noise and harshness is gone. Each road bump is no longer felt, just heard sometimes.

There is a slight vibration in the steering wheel at speeds over 60 MPH, but another balancing on the Hunter 9700 machine with the roadforce should cure that.

Installer did not have to use much weight to balance the tires.

I may yet keep this car!!

[csnow]

Your speedometer is going to be off. Your tire diameter went up.
A higher aspect ratio (65) requires a narrower tire to maintain diameter, not a wider one.
Assuming the old tires were stock, I calculate your speed will read about 5% low.

195/65 would have been closest.

Contrary to the charts on the wall at the tire store, low pressure will cause radial tires to wear down the middle.

Good luck,

[zafarhayatkhan]

I had an error in the earlier post, the new tire size is 215/60!

[csnow]

That's more like 2%

[zafarhayatkhan]

If I go back to the original 195/65 size, the ride may improve further.

[csnow]

If 195/65 was the stock size, than you are within 1% with 215/60.

I think you made a good choice. The extra width is worth some grip. I like the GTs. Good balance of properties. Treadwear is only ok, but otherwise good stuff.

[MrCjames]

You may want to mention to your local tire specialist that you would prefer to have the weights added to the wheel one at a time. Meaning: spin the wheel add the weight to the outer edge, spin the wheel again then add that the weight to the inner edge.

I have discovered a difference with two minor things, 1) up to 3 grams off and 2) the placement/location of the weight.

I found this method to work the best for Goodyear tires.

If your tech has to put the weights on in two different spins to get it right he is using a balancer that should be properly calibrated or scrapped.

A computer balancer in proper operating condition and calibration will get a proper balance by placing both inboard and outboard weights where the machine indicates after one spin. Then respin and check. Make sure that they use weights inboard AND outboard. Otherwise you are only getting a static balance and the wheel, especially if mounted on the front, is amost guaranteed to vibrate.

Best of luck,

[zafarhayatkhan]

One of the front tires does not have any weight on the outside.

Either the tire is very good or the installer forgot to put the weight on. I'll have to get it checked.

[MrCjames]

Originally posted by LarryBible
If your tech has to put the weights on in two different spins to get it right he is using a balancer that should be properly calibrated or scrapped.

Larry with all due respect, I believe my comment referenced the tire manufacturer and not the equipment being used to perform the balance. In my experience, 15+ years at dealerships, I have discovered that Goodyear tires simply balance better with the method stated in my previous post. I have seen up to a 4 gram difference with weight, and a weight placement difference up to 5". I could mention that this was also discovered with a new Hunter road force balancer right out of the box but I won't.

Just my .02

MrCJames,

When you do this are you putting on the first weight in STATIC mode? I have never tried that.

That said (asked,) I am still quite suspect of this approach. 4 grams difference would be imperceptible on the car. If you put on one weight in dynamic mode and respin, you will, of course, have the balancer tell you a different location for the second weight than if you had put them both on in Dynamic mode when the machine first told you where to put them. Just because the location is DIFFERENT does not mean that it is more accurate.

The machine is resolving differently the second time because it has different data.

I respectfully disagree with your method. I think you have insufficient data for a conclusion. I expect that the wheel is balanced with either method. Does your machine give you a zero after putting on both weights with the same spin? Does the machine also give you a zero after using your method? I expect that the answer would be yes in both cases. If that is indeed the case, then your method is accomplishing nothing except costing you extra time to balance the wheel.

I will experiment the next time I do some balancing.

Have a great day,

[Rockman59]

I had an error in the earlier post, the new tire size is 215/60!
___________________________________________________
Your speedo now reads 2% slow.....when your speedo reads 60mph your actual speed is 61.2 mph when comparing the 205s to the 215s...

[MrCjames]

Hi Larry

Again, I would like to mention that the experience I have had is with Goodyear tires, other brands have usually not been a problem. 4 grams of weight is a perceptible amount when the wheel is mounted on the front of the vehicle.

When you make time for this experiment please let me know what your conclusions are with Goodyear tires. I agree that mathematically it should not matter but how many times has theory been proven wrong by reality?

Be

I won't be able to experiment with Goodyear tires since I refuse to buy them. Maybe you are offering one of the reasons why I don't.

I will be doing some experimenting with other brands.

Have a great day,