Baron11

Just went on a trip from Fredericksburg VA to Crossville Tennessee. I wound up getting better than 26mpg, this mileage was calculated by hand. Avg speed by OBC was 68mph, that includes speed zones from 25mph to 70mph. This included about 25 miles of towing a 2,500 lb trailer and the entire trip was in the rain, sometimes heavy rain and hilly terrain up and down I81.

I found this mileage to be incredible for the size vehicle. Just thought I would pass this on.

Bryan

Brocktoon

Amazin', huh?

Baron11

I knew it would be good, but given the weather and 'poorer' fuel mileage in rain, I never expected it to be this good. Matter of fact at one point I thought my gas gauge was not moving, I was at slightly less than a half tank with 550 miles and the gauge hadn't moved for loooong time. Wonderful surprise. It is just as quiet as my E320 Bluetec and just as smooth. The seats aren't as good as the E but 8.5 hours each way and my back never hurt, so no complaints there.

My pet peeve is who in the world is actually testing these diesel vehicles and coming up with crappy fuel mileage? The highlander hybrid does not even compare. (We actually looked at it, but decided we wanted more than 6" of space between the third row headrest and the backwindow) The yukon hybrid, no thanks.

Just totally pleased. The GL does have a few issues, but they are minor compared to what you are getting. (Minor as long as you have a way to jump start the car if the battery dies.) This has only happened once and hopefully has been solved now.

As a side note, all our vehicles are diesel now.
Jetta TDI, E320 and now GL320. Even our house runs on diesel. ;0

Bryan

Wigwam

I have never calculated mpg by hand, the on-board computer shows me getting only about 20-21 MPG in my GL320. Are your calculations that much better than what the on-board computer says?

scottybdiving

The most accurate way is always miles driven/gallons consumed. The larger the sample the smaller the error (i.e. Total miles driven on a long trip / total fuel consumed). The on-board computers do not have meters that measure fuel. They only estimate fuel consumption based on an algorithm. My Silverado also shows actual fuel consumption and it is always off (low) by at least 1 gal or more at every fueling.

Our GL 320 has never reached 25 mpg, usually 22-24. It has only been on one trip of 400 miles, for which it was driven pretty aggressively.

Brocktoon

I had understood that modern trip computers like ours are tied into the fuel management software' and were pretty error-free.
Maybe it is something in the units conversion because mine has only ever been out by very little when I have done it by hand. You also have to trust your distance/ odo.

Danno4x4

My Fuel Mileage as listed in the computer has consistently been erring on the low side... Sometimes as much as 2-3 MPG... I tested it on several long trips 800-1000 miles plus where I calculated the fuel consumed to the miles on the odometer...

Baron11

My VW tdi mpg MFD is always high, in other words it will show 52mpg when in reality I am getting 46mpg. I only use the mpg counter for each tank, basicly I only care about the avg fuel used per tank.

My E320 is mpg MFD is slightly high but only ever by 1 or 1.5 mpg, so relatively accurate.

The GL320 seemed a bit low, if is remember correctly I was showing 25mpg and change on the MFD, when calculated I was getting something like 26.2 or so.

Steady rate speed is what the diesels are all about, nothing new to us. The sweet spot on the GL seems to be around 70mph or so. My mileage at 70-72 was better than my mileage at 55 to 60, but this could have been due to many variables. My hunch is at 70mph the car is running more efficiently, I didn't notice a mileage drop off until around 77mph.

Bryan

StevethePilot

I'd say that's city drivin', rather than interstate cruisin' mileage.

Just a thought.

LEOSOPHIE

I agree, my 550 gets 20mpg at 70 or less. I got 19.2 between Fresno and Phoenix 1200 miles round trip.

sleewell

that is phenomenal gas mileage, i am impressed.

I went to Vegas last weekend, when i turned off my car as i got home it said 29.9mpg.

20 bucks and a half tank of gas each way, not too shabby since i was doing 80 the whole time.

Fourdiesel

C230 mileage is expected to be very different than the GL 320.

scottybdiving

How much would it use pulling a horse trailer and 6 adults?

StevethePilot

Why would you be pulling 6 adults? Let 'em sit inside, for goodness sake.

sleewell

uhhhhhhhhh, obviously i know the two vehicles aren't the same - but thanks for that brilliant heads up. hey, the empire state building and my house are also different and each take different amounts of electricity, did you know that?

i was just making conversation and comparing that a much larger vehicle with much more weight got about the same mileage but i also learned a GL is not same as my C: sweet.

thebishman

I have also seen great mileage with the CDI. We returned from Boulder, CO last October, and at an average speed of 75 mph, (over 550 miles), we managed to get 25.9 mpg according to the on-board computer.

However, the GL is extremely susceptable to strong headwinds as going to Boulder, we only managed 19.9 mpg. This was during a severe winter storm though.

Bish

scottybdiving

So the horses could sit inside, of course.

StevethePilot

Still very good mileage for a big V8, I'd say. My LX470's best days were about 14mpg, on long cruises at ~70. Normally it got around 10-12 in mixed driving.

StevethePilot

Good man, got your priorities straight at least.

dariof

28.1 highway for a 975 mile trip from Las Vegas to Carson City and back. This 2008 vehicle has 11,000 miles.

I had the cruise set to 80 when possible, and at places, passed other vehicles at 95+.

I was more than impressed.

When I first purchased the vehicle, I was getting around 26 MPG on the highway.