I thought these cars were supposed to have terrible gas mileage? :-)



Drove leisurely for this but still, pleasantly surprised!

Yeah mine says about 23 on the hwy which is great in my opinion. But I buy cars for smiles per gallon.

I was expecting much worse than my former M3 with the 4.0.
This actually seems very reasonable for a 6.2.

Smiles per gallon gauge is pegged

I don't see this as anything special if you are cruising at more or less constant speeds on the highway. It is urban driving that suck the tank dry.
I like to watch the mised driving numbers.
My E350 4 matic 2011 wagon would give me 8.8-9.0 L/100km on the highway but mixed was 10.6L/100km.
My CLA45 AMG would get down in the 7.8-8.0 L/100 km but the mixed was around 9.4-9.6L/100 km.
This beast with the performance package will give me 10.5-10.8 on the highway but the mixed is in the 12.5-12.8 range. Curiously all these cars show a mix average speed as a daily driver of arond 56-60 kph.
I always think of gas as the cheapest thing I put out on cars. I like the notion of smiles per mile too.

You guys are all insane. Im over 20L/100km with mostly city driving. Average speed is probably 15-20kmh which really hurts.

And absolutely agree with the smiles per kilometer metric. Smile width = 1/fuel efficiency.

Get your system checked mate. Were you the guy asking about cleaning sooty tail pipes that were coked right up? Could be. clue you are running rich as hell.
At worst under those conditions I never see over 16.

I cannot comment upon the canadian measurements; all the Litters and Kilo presentations have my math brain sputtering. I can say, however, that I too have been pleasantly surprised by the highway mileage (I've had my '13 C63 about 3 weeks). About 22mpg average highway mileage, at 75 mph average, including over mountain range (Blue Ridge, Charlottesville, VA). This equals or exceeds my former W211 E55 supercharged. Not bad for such a large motor. Very pleased. City stop and go is brutal, but the cruising mileage is solid.

It is simple 10L/100 km = 23.8 mpg US or in your case 22 mpg is about 10.9L/100 km which is about what I see on a straight highway run. Best ever in the 10 months I have had this car was 10.6 at about 60 mph.

Im the same here Alex, minus the super sooty pipes. I'm right in town so its all stop light to stop light, and that tends to be how I drive it.
I have unlocked my inner 16 year old lol.

Every time I get a chance to drive on the highway I am VERY pleased by the mileage, so even some sort of mix would go a long ways.
I hate those damn idle shutoff things in the new cars, but cant help but wonder how much gas/time I waste at stop lights. The time factor is certainly high.

Two cars - SLK350 and ClA45 AMG - had the eco feature of engine shut off.
I worried about the starter but after taling with my guys I relaxed.
In the SLK V6 the starter motor came on. occasionally. I am told in the V8s it is rare that it restarts the engine.
This is because the system knows the optimum cylinder in terms of piston position to kick the engine to start it. All it does is deliver spark and fuel and the movement of that cylinder rolls the motor and away you go.
The 4 of the CLA45 used the starter what seemed to be 25-30% of the time.
I cannot recall the specific data but I did test both cars over a period of a few weeks were I shut off the ECO start and I did notice fuel economy was not as good without it in my mixed driving when compared to what it was when it was on.

That is correct, AMG's don't use the starter with eco mode. My e63s had the feature.

You may want to track actual fuel usage and distances between fillups before celebrating TOO much. Most users have reported that the car's mpg calculator is optimistic, typically by about 10%.

My car has proven capable of some surprisingly good mpg numbers when driven very carefully. However, that isn't much fun. I've noted an inverse relationship between the level of grins and giggles while driving vs the level of groaning at the next fillup. I like the smiles per gallon concept a lot!

I have yet to see anything close to that number haha. Never taken the car for a long trip, mostly city driving. 10-12mpg at best with very tame driving.

This is the best thing I've heard this week. I'll be saying this from now on when the haters say "yeah, but how about your mileage?"