... one horsepower per cubic inch in a world of engines more typically making one hundred horsepower per litre?

I realize there's a horsepower sacrifice made to produce the low-down torque needed for the Phaeton/A8/Bentley applications, but is anyone else at least slightly disappointed that Audi's 6.0L twelve makes less horsepower than its 5.0L ten?

I mean, there were cars in the 1960's making one horsepower per cubic inch and still producing a bunch of torque -- without variable valve timing, without variable intake, without fuel injection, without exhaust flow monitoring, without oxygen monitoring, without four valves per cylinder, without advanced metallurgy, without lightweight internals, without advanced lubrication schemes, without any of the things the W12 benefits from...

... I still love the W12.

Just wish they'd done more... two narrow angle 3.0L V6's each making 300hp doesn't seem that hard to achieve, normally aspirated, especially when they started with the blank slate they did...

The 6.0 has more than 360 HP, doesn't it? Isn't it in the 400 HP to 450 HP and 400 lb-ft of torque range?

That would be more than 100 HP/liter.....

And it passes emmissions! No car in the 60's could of done that.

pw

some HP would get lost in the link. No?

the W12 has something like 95% of that peak torque available across somethig like 80% of it's rev range. That's quite some shove.

I suspect a similar situation to the RS 6 exists, in that the engine output is being limited deliberately both for market positioning and transmission protection. The RS 6 had a really flat peak torque "curve" because the peak was around the limit for the 5 HP 24A gearbox. The W12 uses the 6 HP 26A gearbox, which is rated at 600 Nm / 440 lb/ft. The W12 gets close to that, but not close (or slightly over) enough to cause issues with gearbox failure under harsh diving conditions or prolonged high torque use.

If the gearbox had been a 6 HP 32A, up to 770 Nm / 568 lb/ft would have been possible, making for nearer to 540 bhp possible engine output, if the engine could be tuned to produce that much around the 5000 rpm mark.

As an aside, the 4.0D produces more peak torque than the 6 HP 26A is rated for. It's just fortunate that it doesn't get chance to produce it for long due to it's limited rev range.

... and the W12 has huge pumping losses.

And other factors affect it (emissions, has to be able to handle twin turbocharging without many changes to internals, optimized around not creating bad secondary vibration/harmonics in a variety of vehicles, detuned to run on pump gas worldwide so roughly the same fuel maps can be used in the US and UK and China and so on...)

Comment just made for the sake of debate, really.