"Why are the new cars I shop for being equipped with larger tires, for example, 17- and 18-inchers? It can't be weight-related as cars keep getting lighter. My tire dealer tells me larger tires will cost substantially more to buy and last "half as long." – Scott in North Bay, Ont.
A larger-diameter wheel-and-tire package is another way of making a vehicle look distinctive, and it has great appeal among consumers.
When you choose this option, in most cases it also results in a lower-profile tire – meaning the height of the sidewall is reduced.
In general, lower-profile tires deliver a harsher ride over road imperfections, such as expansion joints and potholes, and don't provide as much insulation from road noise. The decreased sidewall also means it's easier to damage the rims on curbs and road defects.
Your decision to up-size may, however, also result in better handling characteristics.
"There is less sidewall roll, so the car handles a little better in cornering and they're a little more stable in hard corners," says Len Kreiser of Fountain Tire in Sherwood Park, Alta. "If you go to extremes, there is probably noticeably better handling. Say if your original-equipment tires had a five-inch sidewall and you go to a low profile, yes it would corner better, but it would ride rougher. Most of the folks going to a low-profile are doing so for cosmetic reasons."
A larger-diameter wheel also provides space for a larger brake disc, and that means more brake-pad contact area.
You're right, a larger wheel will be heavier if the same material is used in construction of both a large- and smaller-diameter wheel. However, alloy wheels of varying weights are available. For example, aluminum rims will be lighter than steel.
So, how do the popular lower-profile tires stack up when it comes to cost and durability?
"As a rule, a low-profile tire is also a performance tire manufactured with a softer compound, so the overall mileage of the product is going to be less than a harder-compound passenger-style tire," says Kreiser. "So they're not better mileage, and generally they're a little higher cost. You've got to want them, and lots of folks do."
Remember, many factors influence tire performance. "There's a wide variety of tires that support different loads and different traction capabilities, having to do with not just the diameter – the width, the profile, the tread compound, the tread design. There's a myriad of characteristics that all roll together and each, of course, will vary depending on the profile of the tire," says Ralph Warner, of the Rubber Association of Canada.
These pluses and minuses with respect to higher-diameter wheels mainly come down to personal preference. If you live in an area where the roads are rough, for example, you'll be happier with a tall-tire, narrow-wheel package.
Unless you plan on spending weekends at the track, you probably won't notice any performance or handling differences; it's all about the looks. And don't forget about the importance of curb appeal when it comes time to sell your ride.
Send your automotive maintenance and repair questions to globedrive@globeandmail.com
Joanne Will