How Do I Calculate Weight Distribution?

Weight distribution is an important factors of vehicle design. Knowing your vehicle's front and rear weight distribution is the first step toward optimizing it for the handling you desire.

Effects

You should always aim for a perfect 50/50 front-to-rear weight distribution. Most cars are about ten percent heavier at the front than the rear, which makes them prone to pushing (understeering) through a turn instead of rotating. A rear-heavy car will have better traction off the line, but will be more prone to spinning out (oversteering).

Measuring the Car

The simplest and cheapest way to measure your car is to take it to your local truck stop and use the scales there. Truck scales are three scales on one platform, set up to measure a truck's steering, drive and trailer axles separately. Truck scales typically are accurate to about 25 pounds per axle, which is close enough for an accurate weight-distribution measurement.

Calculating Weight Distribution

Divide the front axle weight by the total vehicle weight to get a percentage. Then subtract that percentage from 100 to arrive at the split. For example, a car weighs 3,800 pounds and carries 2,200 pounds on the front axle. That 2,200 divided by 3,800 gives you 0.578, which equals 57.8 percent. Subtract that from 100 to arrive at 42.2 percent. Thus, your front/rear weight distribution equals 57.8/42.2, which rounds off to 58/42.

References

• "Advanced Engineering Mathematics, Textbook and Student Solutions Manual "; Erwin Kreyszig; 2006
• "Race Car Engineering & Mechanics"; Paul Van Valkenburgh; 2004
• Autopedia: The Physics of Racing Part 3: Basic Calculations