W212 E550 MPG or Fuel Economy
 

Hi All,

I used the search and couldn't find much information about the E550 mpg. There were some threads where E350 owners discussed their MPGs, so I thought I'd ask E550 owners.

I am especially interested in answers from E550 4.6L TT engine owners.

The declared MPG for these cars is 16 in town, and 27 on highway.

I get really close to 27 MPG on highway while going at speeds between 65-80 mph. I still get close to that number even if I go faster.

But I can't get anywhere close to 16 in town. I always reset the numbers after each full tank refill. I get 11.8 MPG in town, it is never below or above. It always is 11.8 MPG in town, which I think is kinda strange.

I drive between 30-40 miles per hour in town: I don't accelerate like crazy, but I don't drive like an old lady - sane driving.

I bought the car with 31000 miles on it. The car currently has 33000 miles on it. Haven't changed the engine air filter yet, as the manual said that the filter needed to be replaced at 40000.

Do you think changing the air filter would increase the MPG ( I have no idea if it is really dirty or clean. Being to lazy to disassemble and look.)

All E550 owners, please report your MPG, both in town and highway.

Got the old 5.5L NA engine, 14 in the city, 21 on the highway it what I've personally observed from my car.

Thanks for chiming in!

Wow, 14 in the city sounds great, although I would have hated to get 21 on the highway.

I am really pleased with 27-ish MPG on highway that I get from the TT engine. But seeing 11.8 constantly in the city, doesn't look right to me. It never fluctuates. It is always 11.8 :(

Hi Rovel,

In the type of city driving you describe, I usually average 19 to 20 mpg in E mode according to the vehicle's calculation. On the highway doing between 65 and 80 in E mode, so obviously behaving myself, I average 27 to 29 mpg, depending on the length of the trip. Quite happy and surprised by the gas mileage in both cases given the weight of these cars.

Thanks Paul,

Not that questioning your response, but 19-20 in the city is VERY well! Are you sure that you have E550? :) As it is actually higher than the advertised MPG.

If yes, what gas do you use: brand, octane?

How often do you change the filters, spark plugs?

Thanks.

NA V8 here. I get 17-18mpg (manual calc). on average. I mostly just commute which is 6-9 miles each way depending on the route. Average commute speed is 22 mph so I guess that qualifies as city. On straight highway trips where I set cruise between 75-80 mph, I get 25-26mpg.

In 2016, after 8,000 miles and 26 fill ups, my average mpg calc. was 18.47. I had only 1 roadtrip in my car and that was 25.6 going up and 25.47 coming back. Lowest tank was 15.52 but most were 17 or 18. Pretty much same story in 2015.

Thanks thefisc,

Looks like everyone is getting good mpg when driving slow. Why do I get 11.8? :(

Perhaps I need to check with a dealer, but ai doubt they will say smth meaningful.
I will check the filter too.

The TT E550 never displays less than 11.8 MPG. That's just the way the software for displaying the MPG works on this car. That means you could be getting lower mileage around town.

If you drive full throttle everywhere you go, that might explain it. Otherwise, it is not hard to get at least 18 MPG in normal city driving driving conservatively. If you can't get that, something may be wrong.

HI OP,

The 2015 E550 coupe is rated as 19 mpg city. So I am getting the mileage MB spec'ed for the vehicle. I have the car serviced as required for normal A and B service. I put 93 octane Sunoco Ultra in the tank simply because it is the closest station in my neighborhood. In general, I've kept all my vehicles well maintained over the years.

Thanks all for your input.

I am really concerned now. As I indicated in the description of my post, I don't drive like crazy around town and on backroads. I drive normal as an average person does. But I don't see anything other than 11.8. If I reset the reading while driving 30mph, it can show a higher number.
But if I reset as soon I fill up, then drive for 3 days for commuting = 3 miles one way at 20-40 mph, my "since reset" and "since start" will be 11.8mpg.

I do get close to 27 if I reset and drive on a highway at 65-85 mph for an hour or two.

The car has always been serviced at dealer, has 33K miles on it. Have never changed an engine oil though. Always use Mobil 93 gas.

What can be wrong? Is it possible that e-brakes don't disengage fully? Hmm

OP, what do you get if you calculate mpg the old fashioned way, using the change in odometer/trip meter divided by gallons added since last fill up? Just wondering if the display is messing it up but your real life mpg is better.

As long as you have been maintaining your car as MB specs, there is nothing wrong with your car. Tires properly inflated? Not trying to use lower octane, no-name gasoline to save a few cents? You know, the usual cutting corners stuff some folks do. If the car is maintained as it shoild be, then car should be fine.

If you do a lot of stop and go, crawling along in the city driving or sit in bumper to bumper for long periods of time with you not moving much, your mpg is going to stink. Nothing you can do about that, but try to find a better route to and from wherever you normally drive. People who drive in NYC or LA typically get lousy mpg.

Here is a quick question for you. How long does your daily 3 mile commute each way usually take?

Sorry, I am new to the forum. What does OP mean?

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.

Paul,

Actually I just checked with Google Maps, it is 4.3 miles one way, not 3 miles :)

And it takes me 20 - 25 minutes. So I don't think I am hitting too much traffic.

The car works great otherwise. So it is going to be hard to justify when I take it to the dealer and ask them to investigate the low MPG issue. Unfortunately my car doesn't show the tire pressure (which surprised me on a P3 car - it only has the flat run indicator). So I do check the tire pressure once a month manually. All 4 are set to 35 as it says on the fuel door.

The reason I thought about the parking brake is that I noticed sometimes I have to pull the handle all the way out for it to release the parking brakes.

I drive about 9 miles into town every day and my mileage ranges from 11.8 mpg to up to 17 mpg depending on traffic. So what you are seeing is right on what I am getting. On the highway the fuel economy is phenomenal.

No kidding... my 2007 E350 was giving me 24mpg on highway. And this E550 does 27-ish which is great for the engine of this size and power :)

Yep and what is even more incredible is how it just eats up the miles on the highway. In stop and go traffic on the highway yesterday I got about 24 mpg. On longer trips I have been right on the 27 mpg or more.

4.3mi/20min is 13mph average. You probably have low MPG because you're not getting into higher gears.

I try not to think of my fuel economy in terms of miles per gallon, but rather smiles per gallon :zoom:... when my MPGs go down, it's usually because the SPGs went up lol ... but for normal-people reference, I get around 18/19mpg combined and up to 34mpg on all-highway trips... if I behave.

I get enough SPGs too when possible, LOL :)

Is your car warmed up by the time you get to work? Your engine does not run at max. efficiency until the car and transmission is fully warmed up. I have the same engine and my commute is about the same as yours, I get about 12 -13 MPG during the commute. On weekends when I take the car out on the highway, I can get as high as 26 MPG, same situation as you.
You might want to take a look at your air filter, a dirty filter can cause low MPG, just blow it out with air if it is dirty.

I start driving slowly when the car warms up a bit. Waiting until it reaches the full temperature would be too long. But it gets to the operating temperature when I am halfway to the work.
The air filter disturbes me. I gotta check that. I am uncertain whether I should order a new set and replace it, or clean it with an air (if it is dirty of course) and then replace in 4-5 months at 40K as the manual recommends.
Will stop by at dealer today to ask about the 11.8 MPG in town. I am almost positive that won't hear anything meaningful from them, but will give it a shot. Will leave a comment here on what they said.

I don't mean to fully warm the car up before you drive, in fact, I usually just let the run for 30 seconds and drive off, warming up the car too long is a good way to kill MPG. I believe the temp gauge on Mercedes show the coolant temp, my old BMW use to show oil temp. Oil temp is usually a bit behind the coolant temp, so I would say the oil temp is fully warmed up and the car is at fully efficiency when you are 75% of the way to work. You are right that dealers usually dont do much about poor gas mileage, I would ask them to check for error codes, check air filter and maybe plugs. A bottle of Techron would not hurt either.

What I meant with my statement about 13mph average speed was this:

http://www.mpgforspeed.com/fegov_graph.gif
This is a generic graph, but if you're not averaging 55-60mph, you're not getting the best fuel economy. I find that the economy on this car is actually better around 65-70, which could be by design, due to higher speeds in Germany.

I think 11.8mpg for average speeds of 13mph is normal. In other words, your car is working just as hard pushing you around at low speeds and low gears as it would at higher speeds in a higher gear (same RPM), but because you're not going as far in the low gears, your MPG suffers. I think for this car, your best fuel economy will come from being in 7th gear @1500-1700rpm (60-70mph for me).

Thanks for the info and for the graph!

I agree that the car has better MPG when going faster and your explanation makes perfect sense. But you cannot drive too fast around the town, well, at least you shouldn't.

The biggest question is... how do other people reporting 14,15 and even 19 mpg in city get to those numbers? :nix: