In fact, I did a lot better in 600km (average speed 80km/h), achieving 9.1 litres. Granted, that was open-road work, but you'd be hard-pressed to do better in many six-cylinder cars.
For a machine with near-supercar performance potential, I think that's a staggering result. And I didn't even get the benefit of the standard stop-start system.
The new CLS is more subtle, less avant garde in its styling than the previous car. I rather like the new look, which combines elements from the iconic SL roadster with the arched roofline of the gen-one CLS and some old-school touches like the "roundy" rear wheel arches.
More effort has been made to give the CLS a more dynamic driving character than the E-class, with quicker steering response, stiffer suspension and less weight: there's aluminium in the doors, bootlid and some suspension components. Not that the saving is massive - the E 500 with the new engine is yet to appear, but expect the difference to be less than 50kg. Hey, every bit counts.
There's also less compromise in terms of practicality with the new car. Despite the sweeping roofline, rear-seat space is now entirely adult-friendly. The car remains a four-seater, with a business class-style console running between the two back chairs. The boot is more awkwardly shaped than in an E-class, but with 520 litres on offer the CLS is only 20 litres down on its sensible big brother.
It's a magnificent car that plays super-fast coupe and luxury express equally well. But, as is often the case with prestige cars, you have to be careful with the options.
Our CLS 500 had the $4700 adjustable airmatic suspension: a neat toy, but based on experience with other models, I'm not convinced it does the low-speed ride justice.
The switchgear and cabin architecture looked and felt rock-solid, but I wasn't convinced by our test car's matte-poplar inserts and leather/wood steering wheel.
But that's personal taste (or lack of it), isn't it?