The Engine is Beating

There are times that you may see or hear some car terms like (Power-to-Weight) or (Weight-to-Power) ratio.

Do you know what does it actually means? Both have a different meaning despite some similarity in words.

Power-to-Weight ratio is to calculate the measurement of actual performance of any engines or power plant. We can use this terms to compare between engines in terms of performance. The larger the value of the ratio, the better it is.

Formula to calculate Power-to-Weight (engine performance)

• power of your engine in hp / weight of the engine.
• For e.g. 150hp / 500 kg = 0.3 hp/kg

Weight-to-Power ratio is the one that we will normally use in our daily life to compare one car to another car in terms of performance. Do not mix up with power-to-weight ratio which is targeted for engine performance. This weight-to-power ratio will give a measurement of your car performance in acceleration capability. But this is opposite side. The smaller the value, the better your car performance is. Formula to calculate Weight-to-Power (car overall performance)

• weight of your car / power of your engine in hp.
• For e.g. 1000kg / 101 hp = 9.9 kg/hp
• We may take one real sample car to calculate
• Sample Car 1: Toyota Altis 1.8
  • Weight of the car: 1185 kg
  • Max. Output: 136 PS
  • Weight-to-Power ratio is 1185 kg /136 ps = 8.7 kg/ps
• Sample Car 2: Honda Stream 1.8
  • Weight of the car: 1385 kg
  • Max. Output: 140 PS
  • Weight-to-Power ratio is 1385 kg / 140 ps = 9.9 kg/ps