BY TOM AND RAY MAGLIOZZI
Dear Tom and Ray:
There has been a recent upsurge of extremely low-profile tires and extraordinarily large-diameter wheels on all types of personal vehicles. Is this good: stiffer sidewalls -- less lateral movement? Or is this bad: more unsprung mass -- changing suspension requirements? Or is this just an expensive affectation? -- Frank
RAY: It's primarily about style, Frank. People want bigger wheels because they look cooler.
TOM: And if you use a bigger wheel, you have to use a lower-profile (i.e., shorter sidewall) tire so the wheel/tire combination still fits in the car's wheel well.
RAY: The weight isn't much of an issue, because alloy wheels are pretty light. And when you go with a bigger wheel/smaller tire combination, it's pretty much a wash.
TOM: You do get some handling benefits with lower-profile tires. The less-expansive sidewall you have, the less the sidewall will flex on turns. That's good for handling.
RAY: But you pay a high price in ride quality. Because you have less sidewall, there's less of it to absorb bumps and potholes. So lower-profile tires give you a much harsher ride.
TOM: The other significant argument against low-profile tires is that with less sidewall, the wheels themselves are much more vulnerable to being bent from potholes and scraping up against curbs. Especially if you live in a city. And when you have to replace a 19-inch alloy rim and it costs you $750, you're going to wish you'd gotten the smaller wheels with bigger tires, even if you don't look quite as cool when you go to pick up your dry cleaning.