I know that the ratio between kilowatts and horsepower is 0.75:1, but which is which?
If an engine has an output of 100kW, how many horsepower is that?
Just as in miles and kilometres, the bigger number for any given distance is the kilometres number, part of this question is to learn which is the bigger number for any given engine? kW or HP?
Craig Torrens6 times Australian, 7 times State Hillclimb Class Champion
PS is an abreveation of the German word Pferdestärke. PS is a measurement of power, mainly used by car manufacturers, 1 PS is approximately equal to one horsepower, 100 PS is approximately equal to 98.6 horsepower. PS is no longer a recognized unit, KW are preferred. 1 PS = 0.735 KW (approx).
I don't know why 'horsepower' seems to be sticking around longer than other old measurements. No one buys milk or petrol in gallons any more, or buys mince by the pound, or pays for it with shillings or guineas. How many furlongs in a rod, pole or perch?
You have to be a bit careful converting 'horsepower' into kW with the straight x 0.746 conversion. This only works for 'net' (DIN) horsepower, not SAE horsepower. SAE horsepower is not a 'real world' figure as it doesn't count accessories, cooling system, etc.
A '40-bhp' Beetle, for example, is 40 SAE horsepower. That is 34 hp net (or 34 PS), which is 25.3 kW. Likewise, a Superbug is 60 hp SAE but only 50 hp DIN.
All power measurements now are net, and expressed in kW. Surely dyno operators can press a button and have the output expressed in kW, not hp?
PS is actually used alot in japan for modified cars, especially the drift and GT circles and it is almost 1:1 with horsepowerbut obviously gets thrown out when your talking 800hp track machines
Simon I see what you are saying, but that doesn't always apply. Yeah a kW is bigger than a hp, so any engine's ouput will be numerically smaller in kW than hp. BUT - torque in Nm will be BIGGER than in ft-lbs, since there are 1.356 Nm in 1 ft-lb. Yet dynos like to report torque in ft-lbs. Likewise, drag strips report terminal speeds in mph, when a km/h figure would be 1.61 x bigger (and therefore more impressive?)
Even bra sales in Australia don't follow the trend. Is an Australian 14C bra more impressive than a (US) 36C bra? Maybe they should use cm like they do in Europe and sell 92C bras instead.
I think allot of it comes down to tradition. Drag racing seems to be a american based sport, so HP/MPH are used so comparison can be made to the US. HP may still be used, as allow of the older generation (40's and over) had HP, and allot the iconic cars came out in HP.
its noticable though that the japenese 206kw cars all are quoted in kw. While many super cars are quoted in HP ie the magical 500 hp is a nice round number for a high power car to reach. the magical 372.5 kw number jsut doens't sound as good..........
I have no sympathy for my car, only the wallet that pays for it!
Go hard or go home!!!!
Yes all the Japanese and Euro manufacturers use kW nowadays. The new Golf 6 models are even named after their power outputs in kW - the 90TSI, the 118TSI and the 103TDI. Does anyone really care how many horsepower that is?
The Amercans are so out of touch with the rest of the world with their imperial measurements - the US, Liberia and Myanmar (Burma) are the only three countries of the world who have not officially converted. Just think how much it must cost their manufacturing industry, and their importers and exporters, to have to convert back and forth all the time, with an infinite range of products requiring changing or converting. Even the UK - still sticking with their Pound Sterling money - realised they had to convert to metrics to compete with their European trading partners. Constant converting added a financial burden that the rest of their European - and world - competitors did not have.
The US can join in if they have to - the Olympics have been metric since 1896 and the Yanks don't have a problem swimming 100m or running 1,500 m or lifting 265 kg.
Phil74Camper wrote:The Amercans are so out of touch with the rest of the world with their imperial measurements - the US, Liberia and Myanmar (Burma) are the only three countries of the world who have not officially converted.
