Standard vs. Optional Tires: What to Choose?
Automakers today give new-car shoppers a choice of wheel and tire sizes, designs and applications. That's a good way to go because, unlike aftermarket wheels and tires, the ones offered by the original manufacturer are warranted to be safe and durable on the car in question — and they don't violate the warranty. Despite their assurances, your choice affects the car's safety, efficiency, comfort and damage resistance, so it's best to know what you're getting into.
Wheel and Tire Size
One model car may offer more than one wheel size, and in some models, the wheel diameter automatically increases in higher trim levels. For example, the base Honda Civic DX has 15-inch wheels, the LX and EX have 16-inch wheels and the performance model, the Civic Si, comes with 17-inch wheels. Whether they come with upgrades or as options, larger wheels cost more.
Automakers ensure that the tires accompanying each of these wheel sizes have the same external diameter, measured from the tread, which keeps the speedometer correct and allows features like antilock brakes and stability control to function properly. So if the wheel's diameter is larger, the tire has to compensate with shorter sidewalls. Why does this matter? Because shorter tire sidewalls can make for a firmer (read rougher) ride.
If you test-drive a car whose ride quality is borderline firm, think twice before ordering a car with larger wheels if you haven't experienced them on the road. The same applies to run-flat tires, which are sometimes an option in lieu of a spare tire. All other things being equal, run-flats usually ride more firmly than traditional tires.
Larger wheels are also more susceptible to damage. Taller sidewalls don't just isolate you better from bumps in the road — they also help to protect the wheels on which they ride. Hit a bad pothole with a large wheel and sporty low-profile tire, and the wheel is more likely to sustain damage than would a smaller wheel. Further, if you rub up against a curb while parking, a smaller wheel might emerge with no more than a scuffed tire sidewall. A larger wheel, which is lower to the ground, might not survive such a close encounter.
All-Season, Summer and Winter
All-season tires are standard issue for almost all cars; the exceptions are sports cars that aren't intended for cold climates, some of which come only with summer performance tires. Performance versions of some models are the same story: The Subaru Impreza's WRX and WRX STi trim levels come with summer tires while the less sport-oriented trims come with all-seasons.
Summer, winter and all-season tires are self-explanatory in terms of their intended use. What's less obvious are the safety, efficiency and longevity implications. Though they maximize grip in warm, dry weather, the soft rubber compounds used in summer tires harden when cold and become hazardous — and are even more so on snow or ice. (See the companion article on why all-wheel drive doesn't compensate for the wrong tire choice.)
Conversely, winter tires are designed for cold temperatures, snow and ice. Though they excel in these conditions, they tend to have less grip than all-season tires do on dry surfaces as temperatures rise.
Tires and Their Role in Mileage
If you're a stickler for mileage — defined either as fuel economy or longevity — summer and winter tires aren't your best choice. There's no standardized measure of rolling resistance and how tires affect a car's mileage, but overall, summer and winter tires are less efficient. Likewise, they don't last as long as all-season tires. On a government treadwear scale of 800, where higher numbers last longer, summer tires on which we've driven have ranged from 140 to 300, roughly. The typical all-season tire is now in the 400-500 range. Winter tires? They aren't even rated for treadwear and they don't have the longevity of all-seasons either.
Even if summer or winter tires are a no-cost option when you buy the car, they're only truly no-cost if you live in an all-summer or all-winter climate. More often than not, owners with those tires need to switch them twice a year (or at least they should). In these cases there's the added cost of another set of four tires (different seasonal types cannot be mixed) plus the trouble and expense of switching twice a year. Even if you have both sets on their own wheels, mounting, balancing and storing a second set are additional expenses you'll need to keep in mind.
Recommendations
If you're in doubt, we recommend sticking with all-season tires. In addition to the longevity and efficiency advantages, all-seasons perform well in all conditions, and the past few years, we've seen them creep even further into performance levels once known only to winter and summer tires.
For more information on tires, check our Tires and Treads advice section.
