Rolling Resistance Comparator
Compare tire rolling resistance coefficients from compatible tests. Convert kg/t into force and energy per 100 km for your vehicle weight.
Compare results from compatible test methods.
Rolling Resistance Comparator: Tire Size Inputs
Compare two tire sizes here. Use the formulas and reference tables below for this tool's specific calculation.
How Rolling Resistance Comparator Works?
The Rolling Resistance Comparator works by multiplying each tire's rolling resistance coefficient (RRC) by the vehicle's weight to get rolling force and energy per distance. The tool uses 4 steps.
Confirm the test method
Check both values come from the same method, for example ISO 28580 as used for the EU label.
Enter both RRC values
Type the coefficients, for example 6.5 kg/t and 8.5 kg/t.
Enter vehicle mass
Type the loaded mass, for example 1,600 kg (3,527 lb).
Read force and energy
The comparator returns 102 N vs 133 N and 2.83 kWh vs 3.71 kWh per 100 km (62 mi).
Rolling Resistance Comparator Formula
The Rolling Resistance Comparator formula is F = (RRC ÷ 1,000) × m × g, and the energy per distance is E = F × d.
F = RRC ÷ 1,000 × m × 9.81E = F × 100,000 m ÷ 3.6 × 10⁶ (kWh)Δ% = (RRC₂ − RRC₁) ÷ RRC₁ × 100- RRC
- Rolling resistance coefficient (kg/t = N/kN)
- m
- Vehicle mass (kg)
- g
- 9.81 m/s²
Worked example
On a 1,600 kg car, an RRC of 6.5 kg/t gives 102 N (22.9 lbf) of rolling force. An RRC of 8.5 kg/t gives 133 N, +31% more force and about 0.87 kWh more energy per 100 km.
Rolling Resistance Comparator Conversion Table
The Rolling Resistance Comparator conversion table converts 6 RRC values into force and energy per 100 km for a 1,600 kg car.
| RRC | Rolling force | Energy per 100 km | Approx. fuel per 100 km |
|---|---|---|---|
| 6.0 kg/t | 94 N (21.2 lbf) | 2.62 kWh | 0.97 L |
| 6.5 kg/t | 102 N (22.9 lbf) | 2.83 kWh | 1.05 L |
| 7.5 kg/t | 118 N (26.5 lbf) | 3.27 kWh | 1.21 L |
| 8.5 kg/t | 133 N (30.0 lbf) | 3.71 kWh | 1.37 L |
| 9.5 kg/t | 149 N (33.5 lbf) | 4.14 kWh | 1.53 L |
| 10.5 kg/t | 165 N (37.1 lbf) | 4.58 kWh | 1.70 L |
Fuel column assumes 30% engine efficiency and 9 kWh per liter of gasoline, rounded.
What is Rolling Resistance Comparator?
A Rolling Resistance Comparator is a tool that compares how much energy 2 tires absorb while rolling. Rolling resistance comes from rubber deforming and recovering in each revolution.
Rolling resistance accounts for about 20% to 30% of a passenger car's energy use at urban speeds and a smaller share on the highway, where aerodynamic drag dominates.
Only results from the same test method compare directly. ISO 28580 values and SAE J2452 values use different conditions.
What are the uses of Rolling Resistance Comparator?
There are 4 main uses of the Rolling Resistance Comparator, including EV range planning and fleet fuel budgets.
EV range planning
Estimate range gained from a low-rolling-resistance tire.
Fleet fuel budgets
Put a fuel cost on tire choice across a fleet.
Label decoding
Turn a label class into a force value.
Trade-off checks
Weigh efficiency against wet grip.
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