engleg

I drove the old S6 for many years before buying the A6 in 2014. The S6 has a 5-speed manual inline 2.2L 20v 5-cylinder turbo. Highway speeds of 70 to 75mph has the engine in top gear turning in the range of 2900 to 3100 rpm. I always considered this to be a good rpm range for an engine to be in @ highway speeds. So I was surprised that the A6 is more in the 1600 to 1800 rpm range @ highway speeds. I know that the 8-speed transmission and overall gearing allows this. Before owning the A6 if someone would have told me a car of our size and weight with a 6-cylinder 3.0L engine supercharged or not, would only be turning 1700rpm @ highway speeds I would have told them that they are ruining the engine by lugging it with too high of a gear ratio. Modern engineering is amazing!

McFuzz

My TDI does 1600 RPM at 80 and 1601 at 85

Merlin_AZ

Yeah, I was amazed to see it running under 2000 at highway speeds.
Premium gas costs are less painful when the milage is better.

Acuransx

The ZF 8 speed is among the best automatic transmissions in existence. Gas mileage on highway amazing for an all wheel drive car with this much power and weighing over 2 tons. Transmission largely responsible for that.


Best,
Jeff

KevinGary

The TDI is amazing!

Fithian

I think that the 8-speed and auto cruise are responsible for the increased mileage. While in town, the mileage is in the mid 20's, but on the highway for more than a mile or two, it jumps up into the upper 30's, managing 40+ mpg on more than one occasion, at speeds of 80 mph average. Also have the 18" Goodyear high mileage tires from the factory, which helps some.

newmoon

Yep my 2.0T CVT does 1600-1700 rpm at 70-75 mph. Even when accelerating around town, the CVT keeps the engine at around a constant 1600 rpm where it is smooth and whisper quiet like it is idling. I rarely need to go over 2000 rpm because the 2.0T already produces peak torque of 258 lb-ft at 1500 rpm. Gas mileage is amazing too at 32 mpg for my overall mixed driving, and 33-36 mpg hwy only, so these numbers are what the 2.0T is capable of when ditching quattro.

Raiden256

Have to agree. My 2015 3.0T's happy place is a wide open expressway, 95mph @ 2200rpm. It's astounding to me how quiet and smooth it is there.