Hey there, Big Wheel

So there you are, stopped at a red light with the wife and kid piled into your 10-year-old Camry, when you hear a thumping bass beat approaching on your left. You twitch your eyes sideways and confirm its source: Yep, a slammed SUV with ink-black window tinting is rolling to a stop next to you. As the screws holding your car's dashboard together slowly unwind due to the vibration, your daughter shouts, "Hey, look at those wheels--they're still turning!"

While spinner wheel spokes will certainly go the way of the leisure suit, tastefully executed, large-diameter wheels can be attractive. That's the reason car designers inevitably sketch them into their illustrations of upcoming models, why aftermarket-wheel sales have soared into the stratosphere, and why manufacturers themselves are offering bigger wheels; the Dodge Ram SRT-10's 22-inchers are the largest to date.

While aesthetics are in the eye of the beholder, we wondered how the substitution of mega-diameter wheels affects performance and whether they're safe on that 5800-pound truck. You should wonder the same before you shell out big bucks.

Although swapping on big wheels with short-sidewall tires (let's call them BWSSTs, see "dubs" in related Tire Testing story) is as simple as loosening and tightening lug nuts, it's nevertheless an act of significant reengineering. Those boring, standard wheels and tires you're so restless to replace are, in actuality, highly developed components, painstakingly integrated into the physics of your vehicle's suspension. By tossing them aside, you've just spun the roulette wheel of ride, handling, and braking performance outcomes. Feel lucky?

We did a few simple measurements comparing two wheel-and-tire packages: a pedestrian 18-inch wheel and P275/65R18 tire on a stock Lincoln Navigator and an Oasis-brand 23-inch alloy shod with 305/40R23 rubber unbolted from an aftermarket-modified Nav. On the scale, the standard wheel/tire set weighed 76 pounds. The BWSST package creaked the scale's needle to 84--that's a bit over 10 percent heavier. It's not a lot, but if these were the latest 26- or 28-inch models, the differential would be greater--and even more so with spinners. The increase is all unsprung weight, the worst kind.