Low Profile Tire Damage

Are low-profile tires ruining your ride?

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Low Profile Tire Damage

Low profile tires have become the norm even on family cars and crossovers these days. They look great, and they can sharpen up steering, but are the trade-offs worth it?

A tire’s profile is the amount of sidewall that exists between the rim and the road. Older style tires and car suspensions relied on the flex of the sidewall to absorb some of the shock from bumps.  The downside to this is that when you turn the car, the sidewall can flex, making the car’s handling less crisp.

As a vehicle tester, I am fortunate enough to drive dozens of different new cars and crossovers each year. Over the course of these many tests I have found a direct correlation between “upgraded” low-profile tires and a rough ride that can be annoying, costly, and possible even a safety risk.  The issue is most common on vehicles that have a base tire and wheel package, and then a more expensive, higher trim level that includes – like it or not – a larger diameter wheel (rim) and a tire with a lower profile.  It seems that many manufacturers try to keep the outer diameter the same on all the packages by lowering the profile of the rubber when the vehicle moves up to the larger diameter rim.  This way they don’t need to recalibrate the speedometer and other systems that rely on data taken from wheel-speed.  Some automakers do not re-tune the suspension either, but rather, they leave it the same as on the base model and that makes the ride too harsh over bumps.  The added crispness in the steering is rarely worth it.

Low Profile Tires

The series, or aspect ratio, is the ratio of the width of the tire to the diameter.  Translated, a car with a “lower” series number has less sidewall between the road and the rim.  In the past, 70-Series tires were the norm.  Those days are long-gone.  I’m an enthusiast, and I own a very sporty convertible that has “40-Series” front tires I use almost exclusively in summer, when the roads are at their best.  These tires are very low-profile, but the car’s personality benefits from the crisp handling and this particular automaker seems to have tuned the suspension to handle the inflexible tires.   After many years of ownership I have not had any trouble.  However, these days, lower-profile tires are common even on utility vehicles that come with all-wheel-drive and a tall ride height.

I recently shopped for a compact crossover vehicle. I found a model I liked, and knowing I keep my family haulers for many years, I like to get all the options.  However, when I tested the top-spec Limited version of the crossover with its one inch taller rims and lower profile tires, I felt that the ride was noticeably harsher than the base and mid-trim models which had a very nice ride.  Here in New England the roads in Spring are so bad I want all the sidewall I can get, and a ride that is not too firm.  Handling comes second in my family utility car.  I need comfort and reliability.

As the accompanying video shows, many people who buy luxury sedans have found the tires that come with the sedan are not practical. In an ideal world we would be able to buy a vehicle with the top-trim options package, but with the base size wheels and tires.  Until that changes, I suggest you pay close attention to the wheels and tires on the vehicles you test-drive.  While you are testing the car aim for pot-holes, take the bumpy road on the test drive, and be honest with yourself about the firmness of the ride.  As a last bit of advice, I suggest never buying any car that does not have some form of spare tire.  A can of tie inflator is not a practical solution in a snowstorm, and being towed to a closed dealership instead of having AAA simply mount your spare for you and continuing on your way is not a “luxury” experience.