The 7-speed is what really helped MB get better gas mileage while increasing the displacements by a good amount. However, I don't like the 7-speed control as it picks the lowest gear for you. The 5-speed drops one by one, love it. Sure it's not as smooth, but I like it.

Also, the 550 probably got a green award because of the very very low emissions. It is a very clean burning engine for something of it's caliber (5.5L V8, that is a huge engine). MB engines have always impressed me.

But yes, the computer is a "little" too optimistic. I get about actually 1 mpg less than what the comp says.

 

That does annoy me, when I am driving and I see a red light ahead I will take my foot off the gas and let the car coast and I either stop or the light will change. Also when I am getting off the highway I would coast once I switch over to the exit lane. Well I can’t do that anymore, if I take my foot off the gas the car will engine break until it slows to a crawl. I guess I just have to adjust the distance that I take my foot off the gas to when I am ready to stop, but coasting is not possible in this car

 

Ya, like when I drop the shifter manually, it goes down 1 by 1 (D > 4 > 3 > 2 > 1) vs the 7 speed can drop you anywhere from D to 5, 4, 3, etc. What did they think? That it was too much work for the driver to drop one by one with 7 gears and that the customers would complain.

 

I have the 7-speed in my Bluetec and it definitely coasts and does not downshift; its a pleasure to drive. It seems the Bluetec may have a different default gear change settings.

 

Interesting. The 7-spd in my E550 coasts as well if I take my foot off the gas (on a level road). On an uphill where you're slowing down a lot quicker due to gravity, I notice it downshifts. Also on initial startup I notice for the first 5 mins it downshifts to 1st a lot because I'm already at a low speed and its a residential area.

Also, if say I'm at 65mph and its in 7th, and I downshift one, it goes to 6th. The way I understood it is that if you downshift, it goes to one lower than where its at, so if you downshift and it says "5" you were just in 6th (even though it says "D").

 

It is currently set to S.

 

I just drove a bunch of miles this weekend- all highway and i barely got this car to get past 20mpg. Is there something wrong with my trip computer or my car? I should be getting some decent mpg when on the highways but I cant seem to get past 20 or 21mpg. Should i be going to my dealer to report this? Like i said in previous posts I consider myself a very modest driver. This is quite frustrating!!!

 

Are you resetting the trip computer ever? Because if you never have and its basing it on thousands of miles, its not going to change by much.

Do this .. get on the freeway, get to 75mph, turn on cruise, then go to the trip computer that is based on "start" and reset that screen only. Now watch it. You absolutely have to get over 20mpg over the next 20mins driving at 75mph with a reset "start" trip.

 

Vik888- I reset the trip computer every time I fill the tank. I will try your suggestion and see what happens.

 

Vik888, you're correct. That other guy doesn't know what he's missing. I've seen 28mpg in my E550 on long flat drives using the cruise control. I've seen 26.5 going from LA to Vegas, which is not a flat drive. Also had cruise set at 80 about 1/2 the trip. My computer is close, within 1-2 mpg. I always manually calculate to check.
I do notice a significant decrease in MPG when I'm heavy footed or in stop and go city driving in hilly areas. In those cases, my average since start drops below 20 mpg.

 

Yeah, this will tell you your highway mileage as per the car's computer. It isn't perfect, but definitely within 1-2mpg. It would be alarming and serious if on a level road, a 07+ E350 at highway speeds (65mph-75mph) couldn't break 20mpg.

 

It amazes me everytime. I love the E550 especially since there aren't too many of them around. It is quite rare even in South OC.

I guess I'd be bitter too if I bought a E320 CDI and found out a beast like the 550 was getting "good mileage"

 

LOL

 

07 E550 4Matic, many multi-hour long drives on long lonesome highways at cruise controlled 82 mph always yields 21 mpg on the computer.

 

Have you validated your trip computer mpg against a manual calculation?
I'm in the process of doing that now on a tank of gas to see how close it is. If you can't get past 20mpg on the highway, that does seem low to me (I don't have a 4matic).

 

I reset the trip computer once i got on the highway this morning. I got it up to 25.6mpg- a new record for me! So i guess is the problem the trip computer? Should i disregard it and just calculate my average based on the number of miles i get to a full tank? Also since i was getting these really bad readings was the car really sipping or guzzling during those times?

 

Yes, I agree. LOL!

 

The next time you fill up your tank, make sure you put in gas until the pump clicks off.

Then go in and reset all 3 screens start trip, since reset, and the range screen. This should reset 3 different calculations.

Now at your next fill up divide your miles driven by gallons and compare to the "reset" screen.

You can play around with it and see how it goes. You'll see how easy it is to kill your mileage by driving aggressively.

Sounds like your car is working just fine. Remember, 4Matic cars get 1-2mpg lower than the regular E350's.

 

That sounds reasonable for a 4-matic. If the numbers are important, try something like LoneWolf software. Within a few fill-ups, you'll have a good record of your consumption. It also tracks all of your expenses, and much more. My wife's a CPA and recommends it to her business clients.

 

Seems to me that a lot of info is not posted in regards to fuel mileage.

1) different tire pressure will yield different results
2) type of tires will yield different results
3) staggered tire setup will yield different results
4) all of the above

There is so much more that goes into this. So all these posts with different values need to find a common denominator for a good comparison.

$0.02

 

Let's add in a few more pennies. Each of the following will affect fuel consumption:

1. weather conditions
2. temperature and humidity
3. road surface
4. wind
5. elevation changes

 

Very good mileage. Figure the 5-speed and 7-speed do not really have a difference on the city streets. It's on the highway that the difference comes in between the two.

 

S will kill your mileage. It starts your car in 1st gear always rather than in 2nd. Starts from a full stop eat fuel like nothing else, and starting in 1st gear eats more fuel than 2nd due to the higher RPMs.

 

I've never really noticed a difference between S and C (and mine is a V6). Also, the car lags a lot more with the C mode, not as responsive.

 

Well, if you've ever driven a stick shift, you'll find starting in 2nd = less torque which is the "laggy" feeling you are getting.