BJabs

VAG has a long history of "underrating" the horserpower, torque, and acceleration of their cars, and I'm led to believe that is the case with the current 2.0 TFSI, because 3700 pounds (Sportback), 0-60 in 5.3 seconds, and 252 HP doesn't quite add up, in my opinion. My salesperson stated very confidently that Audi's quoted numbers power numbers are at the wheels rather than at the crank - is that accurate? Does anyone definitively know how much power these engines produce at the crank?

Bill17601

I agree with you BJabs. Interestingly I don’t think it matters much. What does matter is both engines make the car move quickly and impressively.
HP numbers are for bragging rights. Performance says it all.

NoMoreBMWs

I plugged C&D's test data for the S5 Sportback - 12.9 seconds @ 108 mph, 4017 pounds - into the dragTimes calculator and got 382.39 hp at the flywheel. Assuming a 15% drivetrain loss that would be 325 hp at the wheels. So, I'd say that the engine is definitely underrated, and the claimed 354 hp just happens to be in between the horsepower at the flywheel and the horsepower at the wheels.

Added the A5 Sportback - 14 seconds @ 100 mph, 3758 pounds: 281.99 at the flywheel.

Maybebuyaudi

Has anyone tested the 0-60 in sport mode for both models?

NoMoreBMWs

4.3 vs. 5.3.

stan23

look up the dtuk review here on the S4 forum and you'll see someone dynod a stock B9 3.0 motor. Was definitely underrated by Audi.

NoMoreBMWs

They found 298 hp at the wheels. That would be consistent with 382 hp at the flywheel and 22% drivetrain loss - which is very believable for an AWD car with an automatic transmission.

fivefan

Interestingly, C&D clocked A5 coupe automatic 0-60 at 5.0. Audi claimed 5.6. Obviously ambient conditions and other factors make a difference as well.

NoMoreBMWs

5.3 in October 2017.

Anyway, what is really going on here is that less wheel horsepower is needed due to the lower traction losses of AWD and lower shift losses of the automatic transmission. You can really see this in the BMW lineup where manual and RWD is (or was) available with the same engine. Take the 435i. C&D's February 2014 test was a RWD manual. 0-60 took 5.2 seconds, 1/4 mile was 13.7 @ 105 mph, curb weight 3621pounds. In June the xDrive 8AT did 0-60 in 4.6 seconds, 1/4 mile in 13.1 @ 107 mph, curb weight 3781 pounds.

If you use the dragTimes calculator, the first car had 302.74 hp, the second car 346.96 hp - with identical engines! It's funny that drivers of AWD cars with fast-shifting automatics obsess over horsepower and drivetrain losses when in fact their cars do exactly what was intended: they lay down the power far more efficiently in hard acceleration.

N8!

Quoted for truth!