I have been thinking about this for a while now, it's the way power is quoted in cars and I think it's wrong, people buy cars (not engines) and when you buy a car they usually throw in a driveline with it, different car manufactures drivelines/gearboxes take different amount of power so you might buy a car with a higher output at the fly but less at the wheels and it's the wheels most of us use to get us moving. As some people will know I am into boats and problem occured in the 80's when people complained of different make outboards with the same rated HP didnt perform the same on the same boat, dyno tests revealed the engines put out the quoted HP (as they must) but they lost different amounts of grunt through the various make driveshafts, to fix that then then made manufactures quote the HP at the prop not at the fly, makes sense to me.
Yeah, i guess having the spec of the power at the fly gives some sort of consistency between cars.
With driveline etc, power will sure to vary according to wear lubes used.
Also another matter is the inconsistencies between dyno to dyno.
Guess with power at the fly it's tested on the same dyno and a miminum figure has to be achieved (i think thats the way it is).
Example if the 4.0L inline 6 makes 157kw if it makes less it has to be ditched. This is when factory freaks can crope up.
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Simply a matter of having two power output figures for the same car in Manual and Auto form. Every engine is differnt I agree but use the law or averages like they do at the moment, I bet the left one not every AU Forte IL6 that rolls off the line puts out 157kw at the fly.
Don't agree EF, They are happy to quote power now at 157kw or whatever the car is but like you say all dynos are different, different engine oils also change the grunt as does driveline oils, what I am saying is, as they roll from the line this car in stock factory specs put out X RWKW.
This is all part of the bigger is better concept of Marketing (& dare I say it the crux of Mr Flint's Power War comments!!). The bigger the number the better it looks, it doesn't matter how much more practical the number is!
To support my arguement look at HSV (not for too long I don't want anyone getting ill) & how we still talk about 302 & 351 (BOF351 not BOF5.8 )
Also the list of variables is bigger than auto vs manual, tyre/wheel size, diff ratios etc will all complicate the measurements.
sorry, what I actually meant was the power actually getting to the end of the axle not the bottom of the wheel, like on boats you stick a big pitched prop on and the thing might not move, the fact is you have X amount of Hp and if you want to stuff around by putting on a silly prop size or stupid wheel sizes than thats your problem.
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