MKSGR:
noone1:
MKSGR:
noone1:

Since when do they engine dyno cars?

Stick track day tires on your track day car and the number stands. Why would you want to track your car with crappy street oriented tires? We already know that the latest generation compounds are a massive improvement. No reason to think they won't be available for customers.

IMO, the car does as they said it would initially. 1.06.3 is as quick as the 918.

They have been dynoing cars for the last years.

The "special" Cup tires are not available to the market (pre-production). Maybe at a later stage. Of course, using such special prototype tires improves the lap times - but it does no tell us anything about the qualities of the car. I.e. useless test Smiley Only good for the marketing...

Nothing but a professional set up engine dyno is accurate. 40 hp is just error in such high powered cars.

600 hp car
2% incorrect drivetrain loss estimate
2% engine variance
3% rolling dyno inaccuracy

Now you're already possibly 7% off, which is 42 hp on a 600 hp car.

You can be sure they have the knowhow and equipment to do proper tests...

BTW, a car with this much deviation from stated hp would be illegal to use on European roads

That's the thing -- it's not deviating by more than a couple percent. It's the combination of the engine/drivetrain variance/tolerance, test methodology, and dyno accuracy. A couple percent in the wrong direction for each will yield results that vary significantly.