I saw this on an article around here, however, I am not clear about what official and unofficial HP means

Can somebody tell me ?
Thanks!

"With an official 280bhp from its 2.0 litre turbo-charged flat-four and an all-wheel-drive system that's smarter than Orak (the Blake's Seven computer), it has the potential to cause a big upset here. Especially since I've an inkling that the Evo isn't quite as sharp as its predecessor.
Stir in the not inconsequential advantages of the Subaru's extra gear ratio and the fact that, unofficially, it has nearer 320bhp, while the Evo struggles along with an official 276 (unoffically probably nearer 300) and the scene is set for a classic head-to-head"

 

well in japan they got some weird law where they can not produce cars with over 276 hp...something along the lines of that...so people claim that because of the limit placed on hp some cars have more than that but the manufacturer states that it only has 276 to get around the law...usually its just a load of **** tho as dynosheets are never shown...and i think an evo 7 was dynoed and it indeed did have 276 hp...not 300


its not just japan either tho...the new ford svt cobra is said to have 390 hp...but according to dynos it may be upwards of 420 hp...this might be done as to lower the cost of insurance...so more ppl will considering buying it i guess or something...

 

There's a gentleman's agreement in Japan between the car manufacturers to limit the maximum output of the cars produced there. sometimes it is breached in cars that are being produced for foreign countries but it's always upheld for domestic models, the specsheet that is.... In reality some cars pump out more HP than that, f.e. most 7s were dynoed at a little over 300 bhp whereas the 6s were all quite consistent around 285-290. Skylines have been dynoed at abround 320 bhp if I remember correctly.