a2j

http://www.fueleconomy.gov/feg/Find....33256&id=24673

what can I do to my 2008 GL320 to get get EPA to the level of 2013 GL350? What is the difference? Engine size seems to be the same. Turbo size? Tune? Weight?

philfna

I don't think there is anything you can do because they used different materials in the build which helped reduce the weight. An increase in HP, torque, and MPG...unless you can somehow drop the weight I think your SOL.

nynd

Trade it in...

alx

Nothing is needed. Mpg on all diesel gls from 2007 to 2013 is pretty much the same.

mp0i

The mileage for my 2010 GL Bluetec has averaged 22.7 mpg over the last 34,000 miles. Not sure what the EPA used by my mileage is in the real world with 40% highway and 60% city/suburban driving.

a2j

how does reducing weight increases HP and TQ?

Than why does MPG rating is different for pretty much every year from 2007 to 2013? (see link in first post).

FastMoneyPlaya

I think the EPA numbers are inaccurate. I regularly get 27+ mpg on the highway in my 2011 GL350:

a2j

This is what I'm trying to figure out. Did Mercedes change something in 2013 model to get better MPG or they just post random MPG ratings for each year?

FastMoneyPlaya

I suspect the official EPA figures on the older models were inaccurate since several people on this forum have regularly exceeded 21mpg on the highway. Fuel economy is measured under controlled conditions in a laboratory using a standardized test procedure specified by federal law. So there's obviously a difference between testing in a lab and testing on the road.

alx

i used to get close to 30 in my 07.

the new one gets the same.

the mpg meter is off by various degrees in the various trucks. do pen and paper and find out they are all the same for the same driving cycle and style.

a2j

I'm not talking about road vs lab testing. I'm assuming all EPA numbers come from lab only testing. So the test environment should all be the same but yet the numbers are all different.

RostamDastan

2013 GL 350 is only 45 pounds lighter than 2012 (5512# vs 5467#), so it cannot be the weight. I agree with alx; Whether its a 2007-08 CDI, 2009-2012 Bluetec, or 2013 Bluetec, they all get roughly the same MPG. Its the EPA numbers that are messed up. After about 14000 on our 2012 Bluetec, we have 21.8 MPG. This is with 70% city and 30% highway driving. On average we get 20 MPG city and 26 MPG highway. That is no where near 17/21 MPG figures by EPA.

a2j

But 2013 GL350 somehow has more HP and 50 more TQ...

alx

Runs more boost. The older trucks can be hacked to make the same power for short money.

When you stay out the boost at constant speeds - mpg is the same.

KrustyKustom

Using some careful techniques i can get 31.3 out of my 2011. Drives my wife crazy...but i get a kick out of such a big vehicle getting such good mileage.

mickxx

Krusty.... do share

KrustyKustom

I accelerate easy, do alot of coasting and never get the rpm over 2,200. I virtually never use the brakes unless i am coming to a complete stop. Never hit the gas hard, i drive like i have an egg between my foot and the accelerator.

I will post a pic of the mileage indicator..

there is alot of info online on hypermiling any car. Record holder on conventional engine was recently, stock TDI passat over 800miles on one tank. Houston to Virginia on one tank.

KrustyKustom

I think I have the 31mpg shot on my ipod, will check.

alx

Do not coast in neutral with the 7g tranny. Ever. Unless you have a spare transmission.

At highway speeds for the output shaft the input shaft is expected to spin at 1500 rpms or more. Less than that and you are starving the tranny due to low ATF pressure.

Want 30 plus mpg in the gl? Tuck 20 yards behind a semi and you are golden. Chips and cracked windshield are optional.

KrustyKustom

ALX.. I meant by coasting foot off throttle still in D, I never put it in N. I allow the engine to compression brake and slow on its own rather than brake.

I love that OM642 engine, have one in my 2012 Sprinter also....smoooooth motor.

Fourdiesel

I get my best mileage on my 320 CDI my driving long distances, steady speed, downhill, with a strong tailwind! Got well over 32 mpg going down I-5 from Grants Pass in the Siskiu's to Sacramento in the afternoon/evening (that was a couple of years ago)
I had a 2000 Golf TDI stick shift (grandson now has it) that routinely gave me 800 mi per tank around town in a smallish town in SW Washington. Really miss THAT range. 53 mpg by the calculator routinely from tank-to-tank.

320GLCDI2008

There was a good Car and Driver Article - Long Term Road Test on the 2008 GL320, and they returned an average of 22 MPG over the 40,000 mile test. Check it out on their web site, very good article. I'm picking up my pre-owned 2008 GL320 tomorrow, it has the P02 package and 55K miles on it. Can't wait!!!

a2j

I don't need to read articles about that. My real world test is 20k+ miles in one year, avg 24mpg.

320GLCDI2008

24MPG Average?? That's AWESOME!!!

a2j

I track it on www.fuelly.com