Why do car companies advertise horse power at the crank? Is it really just to inflate their numbers, or is there another reason?

 

Marketing..... HP has sold cars for decades.... its also just a universal term everyone knows.....

"how much HP does it have"? Anyone asks that question. It also sells magazines, modifications etc....

Recently in America we have seen HP ratings change to take in effect electric systems/HVAC etc. Thus we saw cars ratings change like the GS 430 went from 300-290hp from 06 to 07 but the performance didn't change. Just the rating.

There was a "Japanese Gentlemans Agreement" in Japan where the top publicized rating was 280 even as cars like the Supra and Skyline had much more. This agreement ended in 2005. Ironically the slow Honda Legend (Acura RL) was the first car to break it in Japan as it was sold with 300hp.

Bottom line most car buyers are not enthusiasts and "HP" is a bragging right for a buyer who knows nothing about cars but can tell people "yeah I have 240hp" etc....

 

I don't see how it is inflating the numbers. If a car has 380hp at the crank at 305hp at the wheels then there is nothing wrong with that. Inflating the numbers would be saying that the car makes 380hp but not telling the public that the car makes 380hp on premium fuel only.

I guess it is industry standard to say HP at the crank. But I believe car manufacturers are now stating hp based on individual vehicles and not just engines.

 

What about the controversy with the GTR deflating their HP numbers. Same with the 335i. There is absolutely no way in my 335 only has 300hp. Why isnt their a law about this?

 

Never heard about this. Can you elaborate on this?

 

To BMWs credit their ponies have always been healthy ones...even their low HP cars perform better than you would think they would.

As for the GT-R, its a rare case. Clearly it has more than the advertised HP but not sure why they did it. Maybe not to anger the competition who seemingly raise HP at will every year.

 

Some magazines have claimed the reason the Godzilla is putting up astonishing numbers is because it produces more power than the advertised 480hp. Some have claimed it to be as much as 530. Also they have done test with multiple GTRs and were getting results all over the place.

It all started when people began to notice that GTR had a faster 0-60 and quarter mile than a z06, even though the GTR's power-to-weight ration was 30% worse than the vette.


Dude, its weird. My 335 is not even remotely in the same league as the IS350. Even though they supposedly are both 300+ a few hp. Which makes me think that BMW just threw out the number 300hp has a random set point. But i wouldn't be surprised if the 335 had like 320 crank.

 

Don't forget that just because a BMW has 300 HP (crank) and a Lexus, or any other make has a 300 HP (crank) car that they are putting the same amount to the ground. Some drivetrains are better (or worse) at getting power to the wheels.

The other thing with the GT-R is that AWD systems are generally said to be a little less efficient at getting power to the wheels compared to 2WD systems and the fact that the GT-R was putting down WHP with such little calculated drivetrain loss (if you believe their 480hp claim) the system was either extremely efficient or the car was significantly underrated, the latter being the more likely of the two scenarios.

 

Aren't GT-R engines hand built? So the HP numbers supposedly varied from engine to engine. The 480 may just be a baseline for their HP numbers.

 

QuachmanES could be on to something. Maybe they didn't want to get caught out like Ford did with the Cobras a few years back, where they essentially reported the top horsepower figure that could theoretically be achieved with an absolutely perfect engine under ideal conditions. Meanwhile, most of the engines fell WELL short, showing as much as 35-40% drivetrain loss on a dyno if you believed the spec sheet. They wound up having to buy them back.

So maybe Nissan decided that 480 was the worst possible output their engine could give, if it was assembled by a drunk out of sub-par parts. Since every engine that turns over and fires will make at least that much (though many will make quite a bit more), it's a safe number. Again, just a theory.

 

Crank horsepower is a better representation of actual engine horsepower. Personally, I could care less about WHP, as it only comes into play when modding.

 

The Ford Cobra engines were not making max power because the production intake manifolds had excessive casting flash which restricted airflow. I believe removing the casting flash was all they did to restore the 305 HP claim

Most turbocharged engines output varies widely with inlet air temperature

 

If a ad says "this vehicle has a ____ HP engine" what should they use?