How Curb Weight Works

Optional equipment can add weight to your vehicle.
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A sunroof is a great option, but did you know that it adds to your vehicle's base curb weight?

A young man sits in his late model compact car, impatiently waiting for the traffic light at a busy ­intersection to turn green. But this is no ordinary hatchback. In fact, the driver spends nearly all of his free time -- and a significant portion of his ­paycheck -- upgrading components and pulling every little bit of power he can from within the high-revving engine. Sure, some items are strictly for appearance, like those dark-tinted windows and custom seats, but the majority of his efforts have gone into making this car fast. Engine, intake and exhaust modifications, and even some aerodynamic improvements, have been made. As soon as the light turns green, the driver is going to prove to everyone at this intersection that all of his hard work has been well worth it. He's confident that his car can beat nearly anything on the road.

Just seconds before it's go time, a motorcycle rolls up to the line beside the would-be street racer. A quick nod from the helmeted rider lets the driver know that he accepts the challenge of an impromptu drag race. Engines rev up as both machines anticipate the green light. A moment later, it's green -- the race is on.

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The hatchback driver gives it his best, launching from the line in perfect time with the light. A short chirp from the front tires as he switches between gears lets him know that he's really hard on the throttle. But his efforts are to no avail. The motorcycle rider has left him behind -- way behind. From the moment the light changed, the motorcycle was off like a shot. The car, even with all of its go-fast modifications, never really had a chance against the nimble bike.

So why did the over-confident car driver get left in the dust? After all, the motorcycle has less than half the amount of horsepower of the car, right? Neither driver made a mistake -- no delay at the light and no missed gears -- yet when the light turned green, the bike left the car behind as if it was standing still. Why?

The motorcycle in this example has just emphasized an advantage that all motorcycles hold over passenger cars. Shift to the next page to find out why the high-powered hatchback lagged behind.