James D. Halderman is an ASE-certified master technician, a member of the Society of Automotive Engineers and the author of 12 textbooks. Submit your automotive care questions to Halderman via e-mail at jhalderman2@juno.com, or write him in care of: Wheels, Marketing Publications Department, Dayton Daily News, 1611 S. Main St., Dayton OH 45409.
Wheels: Kent writes by e-mail: “I have owned three sets of Goodyear tires over the years. I recently bought a fourth set — 235x55R16, Fuel Max. All of the tires have had indentations at different intervals along the sidewalls. The indentations run from the rim edge to the edge of the tread. Each tire averages two or three such indentations around the sidewall.
I have looked at other installed tires (different brands) and have not noticed this condition on them. Three separate Goodyear dealers have told me that these indentations are nothing to worry about and do not affect the wear, ride or safety of the tire. They claim it’s a normal result of the manufacturing process.
The previous sets I have owned did not seem to cause any problems other than a slight wheel shimmy too early in the tire life, in my opinion.
Is this true or should I be concerned about these tires?”
Halderman: The indentations (called undulations by tire engineers) are where the various body plies overlap slightly — about five threads. While they are an appearance issue, they do not reflect any fault and should not affect the tires in any way.
It appears that these indentations are more noticeable in certain sizes or type but if you look closely, these ply overlaps can be seen in almost all tires.
Wheels: I noticed Kent purchased fuel-saving tires. Are these worth looking into purchasing?
Halderman: Yes. Tires that have a low-rolling resistance (LRR) are being designed not only for use on new vehicles, but also for the replacement market. How much fuel can be saved? This is difficult to determine.
All tires that are properly inflated achieve lower rolling resistance as they wear. New tires with full tread depth may cause a slight drop in fuel economy even if the exact tire is used as replacement.
For best overall performance and fuel economy, the best thing that vehicles owners can do is to keep the tires inflated to the pressure printed on the driver’s door placard.
When replacing tires, look for those that are the same size and are listed as being low-rolling-resistance tires.
About the Author