The heavyweight aluminum alloy wheels used in this test were selected because they were designed to emphasize a trendy fashion style without regard to overall weight. The heavyweight aluminum alloy wheels on our BMW test car weigh 27 pounds each (ten more pounds per wheel than the lightweight wheels).

When combined, the weight of the Plus One-sized P Zero Asimmetrico tires mounted on the heavyweight alloy wheel results in a 48.5 pound Tire & Wheel Package which is about 7 pounds heavier than the stock combination.

On the road, this combination was only praised for its ride quality. Our experience showed that the heavyweight wheel's reluctance to be moved as the vehicle rode over expansion joints, patches and potholes actually damped the impact harshness transmitted to the suspension, and forced the tires to absorb more of the jolt. However, when it came to steering feel and responsiveness, heavyweight wheels made the tires less communicative and responsive at highway speeds. On the track, this combination found no praise. It felt heavy and lethargic, and actually reduced the feedback the tires normally transmit to the driver, making the vehicle more difficult to drive at the limit. This made it more difficult for the driver to know how much input was required and reduced the vehicle's ability to transform the driver's input into performance. For that matter, many of our team members compared the feeling of running on heavyweight wheels to that of jogging with ankle weights or hiking with field boots. You really feel the difference when you take them off. The car equipped with the heavyweight alloy wheels and Pirelli P Zero Asimmetrico tires benefited from the handling of the tires but couldn't match the performance of the lightweight combination, and its lap times fell between the other two combinations tested.

While we expected to feel the gyroscopic effects of wheel weight at highway speeds (where at 60 mph they revolve about 13 times a second), we were rather surprised at their influence on the car's feel at the lower speeds on our performance test track drive. Additionally, realizing that the impact of heavyweight wheels would increase as top speeds climbed on a race track (where at 150 mph they would revolve about 33 times a second), it left little doubt as to why professional race teams spend thousands of dollars for wheels which minimize weight while retaining strength.

Finally, we monitored our test car's fuel economy using their onboard trip computers during our road rides. Covering a total distance of just over 350 miles, the three vehicle's average speeds were virtually identical (all within 3/10 of 1 mph). During that time the BMW 3-Series equipped with its Original Equipment Grand Touring Michelin Energy MXV4 Plus low rolling resistance tires averaged 22.8 mpg. The vehicle equipped with the Plus Size Pirelli P Zero tires on lightweight wheels averaged 21.5 mpg, while the Plus Size Pirelli P Zero tires on heavyweight wheels dropped to a 21.1 mpg average.