New and Used Car Talk Reviews Hot Cars Comparison Automotive Community

The Largest Car Forum in the Philippines

Results 1 to 7 of 7
  1. Join Date
    Oct 2002
    Is it just divide the HP by the vehicle's weight?

    Can someone enlighten me on this subject?

  2. Join Date
    Jan 2005
    yun na bro. :D

  3. Join Date
    Oct 2002
    korek!!! 10 points! :D

  4. Join Date
    Oct 2002
    it's just a very rough measure of expected performance though... for example, it doesn't take into account gearing (which would affect the actual power that gets to the wheels) or aerodynamic performance (which would affect high-speed acceleration)

  5. Join Date
    Sep 2005
    So parang rough estimate lang ng power or performance ng kotse un power over weight ratio?

  6. Join Date
    Jul 2005
    Quote Originally Posted by bajumbo
    So parang rough estimate lang ng power or performance ng kotse un power over weight ratio?

    well, it's an exact estimate, just be clear of what u want to measure,,like if u want to get the ratio of engine hp to wt. just what u said divide it, but there is another the hp, the whp or wheel hp meaning the actual power on the wheels, it is usally lower value than the engine hp because of tranmission of this power to the wheels, u can get this by putting ur car to Dyno test.

  7. Join Date
    Aug 2005
    Power-to-weight ratio is a measure commonly used when comparing various vehicles (or engines), including automobiles, motorcycles and aircraft. It is, simply, the power the engine develops, divided by the vehicle's or (or engine) weight.

    The power-to-weight ratio is often used as an indication of likely accelerative performance. Vehicle weights have relatively little impact on top speed, which is mostly dependent on aerodynamic drag. Acceleration, on the other hand, is dominated by the Newtonian acceleration term, F = m x a , so more force (F - from the engine's torque delivered to the driven wheels or thrust delivered by an aircraft engine), will deliver more acceleration (a) for any given vehicle mass (m = weight/g).

    In any vehicle the engine power-to-weight ratio is essential for vehicle power-to-weight ratio. But in an aircraft it's more critical than in any other vehicle because any additional weight requires more lift to be generated by the wings in order to lift it. More lift from the wings automatically means more drag, through a process known as induced drag, slowing the plane down. Thus if any two engines deliver the same power, the lighter one will result in a better plane. Power-to-weight ratio therefore has a much more important impact on overall performance in aircraft, including top speed.

    In this usage the power-to-weight ratio is typically used to refer to the weight of the engine alone, as a useful way of comparing various aircraft engines. The term applying to the aircraft as a whole is power loading, and is used especially in helicopter engineering.

How do you calculate 'power to weight ratio'?