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Aerodynamic & rolling resistance, power & MPG calculator


Enter your vehicle's particulars to get an indication of aerodynamic and rolling resistance and estimated fuel consumption with increasing speed.

Discuss this tool in the forum: Online tool: aerodynamic & rolling resistance - power required & estimated MPG
Vehicle weight [1]:
Crr - Coefficient of rolling resistance [2]:
Cd - Coefficient of drag [3]:
A - frontal area [4]:
CdA6.80 ft2 / 0.63 m2
Fuel energy density (Wh/US gal.) [5]: - or -
Engine efficiency [6]:
Drivetrain efficiency:
Parasitic overhead, eg. at idle (optional, in Watts):
Air Density (rho) in kg/m^3 [7]: - or -
Display range:

Permalink to these results

MPHKM/HAero (a)Rolling (b)Total% Aero% RollingWattsHPHP AeroHP RollingMPG(US)L/100km
581.9365.1267.062.88%97.12%149.880.200.010.20233.961.01
10167.7365.1272.8510.61%89.39%325.690.440.050.39215.341.09
152417.4065.1282.5221.08%78.92%553.350.740.160.59190.121.24
203230.9365.1296.0532.20%67.80%858.791.150.370.78163.331.44
254048.3365.12113.4542.60%57.40%1,267.941.700.720.98138.281.70
304869.6065.12134.7251.66%48.34%1,806.722.421.251.17116.462.02
355694.7365.12159.8559.26%40.74%2,501.063.351.991.3798.152.40
4064123.7365.12188.8565.52%34.48%3,376.894.532.971.5683.082.83
4572156.5965.12221.7170.63%29.37%4,460.135.984.221.7670.763.32
5080193.3265.12258.4474.80%25.20%5,776.707.755.791.9560.703.87
5589233.9265.12299.0478.22%21.78%7,352.559.867.712.1552.464.48
6097278.3865.12343.5081.04%18.96%9,213.5812.3610.012.3445.675.15
65105326.7165.12391.8383.38%16.62%11,385.7415.2712.732.5440.045.87
70113378.9165.12444.0385.33%14.67%13,894.9418.6315.902.7335.336.66
75121434.9765.12500.0986.98%13.02%16,767.1122.4919.562.9331.377.50
80129494.9065.12560.0288.37%11.63%20,028.1926.8623.743.1228.018.40
85137558.7065.12623.8289.56%10.44%23,704.0831.7928.473.3225.159.35
90145626.3665.12691.4890.58%9.42%27,820.7337.3133.793.5122.6910.37
95153697.8965.12763.0191.47%8.53%32,404.0643.4539.753.7120.5611.44
100161773.2865.12838.4092.23%7.77%37,479.9950.2646.363.9018.7112.57
105169852.5465.12917.6692.90%7.10%43,074.4657.7653.664.1017.1013.76
110177935.6765.121,000.7993.49%6.51%49,213.3866.0061.704.2915.6815.00
1151851,022.6665.121,087.7994.01%5.99%55,922.6974.9970.504.4914.4216.31
1201931,113.5365.121,178.6594.47%5.53%63,228.3184.7980.114.6813.3117.67
1252011,208.2565.121,273.3794.89%5.11%71,156.1795.4290.544.8812.3219.09
1302091,306.8565.121,371.9795.25%4.75%79,732.19106.92101.855.0811.4420.57
1352171,409.3165.121,474.4395.58%4.42%88,982.30119.33114.065.2710.6422.11
1402251,515.6365.121,580.7595.88%4.12%98,932.44132.67127.205.479.9223.70
1452331,625.8265.121,690.9596.15%3.85%109,608.51146.99141.335.669.2825.35
1502411,739.8865.121,805.0196.39%3.61%121,036.46162.31156.465.868.6927.06
1552491,857.8165.121,922.9396.61%3.39%133,242.20178.68172.636.058.1628.83
1602571,979.6065.122,044.7296.82%3.18%146,251.67196.13189.886.257.6730.66
1652662,105.2665.122,170.3897.00%3.00%160,090.79214.69208.246.447.2332.54
1702742,234.7865.122,299.9197.17%2.83%174,785.49234.39227.756.646.8234.48
1752822,368.1865.122,433.3097.32%2.68%190,361.69255.28248.456.836.4536.48
1802902,505.4365.122,570.5597.47%2.53%206,845.32277.38270.367.036.1038.54
1852982,646.5665.122,711.6897.60%2.40%224,262.31300.74293.527.225.7940.66
1903062,791.5565.122,856.6797.72%2.28%242,638.58325.38317.977.425.4942.83
1953142,940.4065.123,005.5397.83%2.17%262,000.07351.35343.747.615.2245.06
2003223,093.1365.123,158.2597.94%2.06%282,372.68378.67370.867.814.9747.35

Variables for these results:

Vehicle weight: 830.1 kg / 1830 lbs
Crr: .008
Cd: .34
A: 1.9 m2 / 20 ft2
Fuel energy density (Wh/US gal.): 33557
Engine efficiency: .22
Drivetrain efficiency: .95
Parasitic overhead (Watts): 0
rho: 1.225 kg/m3

Notes...

[1] Vehicle weight: don't forget to include the weight of the driver/passengers, cargo & fuel.

[2] Crr: Coefficient of rolling resistance (rolling drag). A value of 0.006 to 0.010 represents \low rolling resistance tires on a smooth surface; 0.010 to 0.015 represents ordinary car tires on concrete (see Wikipedia for other sample values). You can also calculate your CRR experimentally.

[3] Cd: Coefficient of drag. If you don't know your vehicle's Cd, you can try to find it online (e.g. see: the large list of Cd values at Wikipedia, and the even bigger list of figures from the Mayfield Company, or the Nology Vehicle Specifications (pdf)). You can also determine your drag coefficient through coastdown testing.

[4] Frontal area "A": projected vehicle area as seen from either the front or rear. You may be able to find your vehicle's A value in various online sources (Mayfield Co.), or find a technical drawing you can use to figure it out. Or you can calculate frontal area yourself.

[5] See Wikipedia for energy content of various fuels, in Gasoline gallon equivalent.

[6] Most Otto cycle gasoline engines retain an average efficiency of about 18-20% (Wikipedia: Internal combustion engine: Energy efficiency.

[7] RHO: from the Greek alphabet, the symbol "rho" represents air density. At sea level and at 15C according to ISA (International Standard Atmosphere), air has a density of approximately 1.225 kg/m3 (Density of air - Wikipedia). Density changes depending on temperature, pressure & humidity.

(a) Aero drag formula: 0.5 * rho * V^2 * Cd * A
Resulting units = Newtons

(b) Rolling resistance formula: Crr * WeightKG * Gravitational acceleration (9.80665 meters/second2 - Wikipedia)
Resulting units = Newtons




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