W212 E550 MPG or Fuel Economy
Driving in the city can mean many things, one can get less then 10 MPG driving in NY city during rush hour and if that same car is driving thru a city in Texas or Florida, it can get close to 20 MPG. Remember, you are driving a car with 400+ HP that weights over 4000 pounds, it takes a lot of energy to get it moving from stop.
I thought about calculating it using the method you mentioned. But the problem with that is I cannot be sure that my tank is really almost empty when I fill up. I don't know how much gas do I have left when the warning first comes up, and when the range is gone with "fill up now" message.
For example, if there were 2-3 gallons left, that can screw up my calculations.
It doesn't matter how much gas is left in your tank. Take the miles driven divided by the number of gallons, assuming you fill it up each time.
My trip computer always reads a little high, so I do calculate the MPG directly.
I originally thought there was something wrong with my mpg. Did some test on highway and city driving at night and got difference number. I get the advertise mileage in those conditions.
The roads on my commute are not as busy as in NYC for sure. But one conclusion that I am making is that the reading on the IC when going slow is not accurate. It calculates pretty well on highway speeds as the speed is more constant.
Will still check with the dealer though. Will ask them to check the air filters too.
I drove 4.5 miles from work to home. It took me about 15 mins or so.
There were about 10 stops and red lights. The 40 MPG you see on the picture was on 1.2 miles long straight bit of road where I was going 40mph.
If I sum up all the numbers on the pic and divide by 14, I get 13.5 mpg which indicates that the "from start" reading on the IC could be inaccurate.
Last edited by Rovel; Jan 20, 2017 at 05:52 PM.




My trip computer reads high also - between 0.5-1.0 mpg too high.
The Best of Mercedes & AMG
My trip computer reads high also - between 0.5-1.0 mpg too high.
During more dedicated highway driving using E I've seen over 30MPG reported by the trip computer. Not sure if this is accurate vs. trip/gallons calculation, but this car impressed me with better mileage than my last awd sedan (Acura RL with more than 100 fewer HP). -1-2 MPG average with 4 Snow Tires and winter fuel blend on this 63k miles, OE tuned beast.
-Adam




If it makers you feel any better, I did a test this morning. From a cold start to work, about 5.5 miles and around 12 stop lights, I got the same as you 11.8 MPG.
If I look at the consumption on the Comand screen (see the picture above) instead of the Since Start on IC, my average in town with an average speed of 13mph is 13.5 mpg.




The actual MPG normally is 1.5 lower than the car displays driving including 10% - 15% city traffic but this was 100% interstate highway, which allowed me to get that high average speed, and for that I think the actual is only 1.0 MPG or less below what is displayed..
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Last edited by Arrie; Sep 14, 2018 at 03:42 PM.
* City mileage with moderate “stop and go” is consistently 20.5-21.5mpg.
* Hwy mileage is 26-28mpg and seems strangely impervious to the speed travelled.
In comparison to my old ride, my 2012 E550 is faster, has awd vs rwd, is 700lbs heavier, gets the same city mileage and better hwy mileage. This is progress!




The 11.8 does sound suspicious but if you take the same route at the same time every morning... that may be correct, but like others have said check your MPG manually. Fill the tank, reset the trip meter, drive for a week, fill it again and note how many miles you drive and how many gallons you used... say you drove 25 miles and used 2.1 gallons, miles/gallons... you get 11.9mpg
True statements.... cruising at 15mph means your in 3-4 gear maybe... not good for gas mileage

Our City Traffic in Sarasota means us NOT going on the main roads and sitting in traffic, we tend to skirt around the outside and hit less lights, go faster aka higher gears and average around 19-21mpg... these TT V8's have tons of torque down low so you can tap the pedal gently and it accelerates kinda like an old big block car... no need to really nail it like Smaller NA V8's...
Highway mileage is phenomenal for us like people have said 27+ ... we went from Sarasota to Chicago last year. Averaged 27+..... that was cruising at 80-90 plus... even got the ticket

Hope this helps,
Mike
P.S. Don't ask about the AMG gas mileage that will just make you cry...
That one is measured in smiles per mile 
I've seen as hight as 28.5 over a 30 mile commute, but that's not the norm!




The actual MPG normally is 1.5 lower than the car displays driving including 10% - 15% city traffic but this was 100% interstate highway, which allowed me to get that high average speed, and for that I think the actual is only 1.0 MPG or less below what is displayed..
.
I had a stretch of 5000 miles on the odo with mpg at "--.- mpg", probably because it was so terrible

Might also be related to ecu tune + heavier foot...





