By Jeff Bartlett February 1, 2014 12:00 AM
Plus-size tires: When more is less
Larger wheels and tires have taken the fast lane, from street racing to showroom. Tire wheels sized 16- to 18-inch are common place on new vehicles leaving the factory. Older cars still on the road today typically came equipped with 14 and 15 inch tires.
The big-wheeled look has also grown into a significant aftermarket business for tire dealers as drivers increase wheel diameter anywhere from 1 to 8 inches or more beyond the originals—known as plus-sizing.
Style is fueling most of that growth. But retailers also point to more cornering grip and handling. The larger the wheel, the shorter the tire's sidewall and the wider its tread must be to maintain the same outside tire diameter and prevent reducing the tire's load-carrying capacity. The shorter and wider the tire, the better the handling and cornering grip.
You may not care about snow traction if you live in the Sunbelt and drive mostly on dry roads. That's where the wider footprint and stiffer, shorter sidewalls of large plus-size tires perform best. But driving through puddles is more treacherous wherever you live. That's a compelling reason to choose the plus size closest to the original wheel and tire size, which offers the most performance gain with the fewest sacrifices.
Increased risk of damage from potholes and curbs is another consideration. Besides compromising ride, shorter sidewalls provide less cushioning for wheels and tires. Our pothole test bent the plus-two and plus-three wheels on our BMW 5-Series and damaged the wheel and tire on our plus-two-equipped Honda Accord.