cadetdrivr

Sounds like you need to bid over to a Boeing.

(Just kidding.)

A300Capt

i've flown Boeings and they aint much better

arich

Just completed another trip from NYC are to Albany, NY area. on the way up there was traffic so I did not use cruise control, just went with the flow. I got 28.7 mpg over about 100 miles and I was not even trying to drive conservatively. On the way home the roads were empty I set the cruise control at 67 so not to attract unneeded attention. The truck on got 26.7.
Lots of evevation changes on this particular throughway.

Thats two trip where I played with the CC and lost mpg with it activated. has anyone else had similar experience?

I will also mention that I love the way the truck auomatically downshift to engine brake on steep ascents. Almost don't need to touch brakes.

blittle

Just so you guys can compare...... I've been getting around 22 on my 400 mile runs to New England and 16 on the around town runs.....not bad for my big ole V8 and better than I got on my previous two 450's.

emilner

I regularly get 28-28.6 on NY upstate highways (quite hilly). Around town on Long Island I average 22mpg. My wife around town averages 16, but she considers the gas pedal an on/off switch....

JimBarnhart

I have one of those too!

emilner

True story- We had a 2010 Escalade ESV before the GL. One day my wife asked me why the yellow light comes on in the dash when she leaves a light/stop sign. I told her it was the traction control! Yep, she was spinning the tires on a 7000lb AWD SUV with regularity!!

paomien

patyoung

After about 20,000 miles I'm averaging 22.5. Highway trips top out around 24, this is in the Southeast so that's cruising around 80 mph.

A300Capt

just got back from 3200 mile trip and i found out quick that the onboard MPG isnt accurate........i drove 75-85 and the best i got with some mixed driving was 23.7......most of the tanks were 22. thats using refill amounts and miles driven and not the fancy readout that isnt right.

Ed Wolcott

I was going to comment on this earlier. The onboard computer Mercedes uses is more accurate than some others, but the only accurate way to check mileage is to fill the vehicle up each time, and divide the miles driven between fill ups by the quantity of fuel used. This is the basis for the figures I report. I've found the Mercedes computer reads 10 to 20% high.

emilner

That's the method I use as well. 10-20%? Wow that is massively off. I have never had it off by more than .5mpg. I reset the DIC each time I fill and divide the mileage by gallons pumped (obviously there can be a small difference depending on how much you pack the tank. Both my GL and S550 are very accurate. Now all of the BMWs I've had were very very optimistic....

Ed Wolcott

Yes--10% seems to be about average--if it reads 29, the actual is 26 or so. It's a lot better than the computer I have on a Jeep Liberty diesel, when it says 30, the actual is probably 24 or so, if not worse. Actually, with the Mercedes, after thinking about it, I would say 5% to 10% is probably typical. I'll start recording it so I will have actual numbers.

Highway cruiser

1200km seems a lot! Are you driving a pre-2012 model or post-2013 model?
I heard the fuel warning light comes earlier in 2nd gen (2013 onward) cars then 1st gen. That's say when the fuel warning light comes on in a 2nd gen model, you can hardly put more than 23 gallons in it. But in the first gen car, you may sqeeze some 25 gallons in. I'm not sure if this is true though.

ovul82jazz

We have a May 2014 production model. That said, we don't live in gallons up here so its a bit difficult for me to convert easily anymore. I used to be bilingual (Metric and US) but I have to admit that I do not really understand the US system any more. When we drive to the US I even have to set the control panel in the car to US so I can at least match the speed limits but the GPS is left running in Metric so that I know how far I have to go before the turns. Its an odd bipolarity.

So, I don't really know how large the tank is, or if the diesel in our part of the world has a little different formulation or if its an altitude thing. When we're in the mountains, which is relatively frequently of late, fuel economy improves noticeably. If you keep the speed at 100 and there isn't any wind its pretty amazingly efficient.

Highway cruiser

Lol I'm also from Canada (Toronto), so I use metric for most of the time. But I don't own a GL350 now, so most of my information ofGL350 comes from this forum and everyone post their tank capacity and fuel consumption in imperial so I just to lazy to convert them to metric lol.

So may I ask you after you drive 1200+ kms, how many liters of diesel do you pump into the tank? do you refuel before the light come on or right after the light come on or wait until it's dead empty?

ovul82jazz

Its a good question and I don't know the answer... I only did it once when we got the GL just to see what the limits were. I'm actually on a long 'doggle now and will try to keep good records over the trip. I'm in the US now so the conversion is messing with me but we'll see where we get. Also heading to the mountains in a few weeks so I'll keep track there as well. Last fill was in MN and the pump sticker said that between Apr and Oct they used 10% plus biodiesel in their ULSD fuels. I took a pic on my phone just to see if there was any contradiction there with others' experience. Once this tank is burned I'll dig in.

ovul82jazz

OK. I just returned from a 6182 km journey to the US mid-West. Fuel economy overall was 7.9 l/100 km. The load was moderate, prevailing Westerlies on the way out - lots of local running about whilst there - and, the most nasty, twisty headwinds possible for 2 full days on the way back.

All of the fueling stations throughout ND, MN, IL and IN had a sticker on the pump that said that the fuel had between 5% to 20% biodiesel, but all were labeled ULSD. I am not sure what exactly this means relative to the fuel quality discussions that have been taking place.

I did not test the reserve light function on this trip b/c I did not know where the next station might be. I'll get after that on our next trip towards the mountains which will be likely before the end of June. On a local fill, I let the light pop off before filling and put in 101.3 l.

We'll see where the next bit gets us.

JimBarnhart

We ran 10% bio in the summers in Minnesota and I didn't see much difference in fuel economy. But of course warranty coverage is speculative. One of hte reasons I got rid of mine.

Highway cruiser

Great information. Thank you for posting them here. look like it is capatable of more than 1200km in theory. Can't wait to see the result of your next trip~

43221B

If you top off your tank, which involves slowly pumping the diesel in while the extra air escapes, you can put around 30 gallons of diesel in. Obviously, you can only do this in the diesel. In my X164, I got over 720 miles on one tank and that included driving through the Appalachian mountains at 75+ mph. I still had about 70 miles left on the range computer when I refueled. On the X166, you should be able to get further with the better fuel economy. You want to avoid running out of fuel though at all costs because you may not be able to restart it since it's a diesel.