# How to Work Out a Car's Horsepower Per Ton

by C. Taylor
Out of Rubber image by JDsheely from Fotolia.com

Everybody advertises a vehicle's horsepower, but horsepower by itself doesn't mean much. A heavy vehicle can bog down a high horsepower, resulting in poor performance. Likewise, a lighter vehicle doesn't need as much horsepower to go very fast. To take into account the weight of the car, performance enthusiasts frequently cite horsepower per ton. This gives a more accurate picture of a vehicle's performance by taking into account the horsepower as it relates to the weight it must move.

## Step 1

Look up the vehicle's horsepower and weight in kilograms. These are usually available in the manufacturer's brochure or specification sheet.

## Step 2

Convert kilograms into metric tons, which are most frequently used when calculating horsepower/ton. One metric ton equals 1,000 kilograms, so just divide the number of kilograms by 1,000 to get the number of metric tons, or tonnes.

## Step 3

Divide the horsepower by the weight in metric tons. As an example, if you had a 400 hp car that weighed 1.5 metric tons, then it would have 267 hp/ton. If you had a 200 horsepower motorcycle that weighed just 200 kg (0.200 metric tons), it would have 1,000 hp/ton. Notice that the motorcycle has nearly four times as much horsepower per metric ton, even though it technically has half the actual horsepower.