Do you really want to keep the EC activated all the time? My '96 doesn't engage the compressor at all unless the heat is off or the defroster is activated.

It's good to turn the compressor once in a while during the winter. The slight extra fuel you burn to do so will be rewarded with longer life for the compressor shaft seal.

Use the defroster, the winter months around here tend to put that feature to very good use.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Won't the EC button defeat the compressor operation when in the defrost setting?

Update since my last post. I turned on the EC button on my climate control. On my last two fill-ups, I've average 30 mpg as opposed to the 28 I was getting before. I need to drive some more but it looks like that EC button has helped some.

Scott

__________________
Scott
1982 Mercedes 240D, 4 speed, 275,000
1988 Porsche 944 Turbo S (70,000)
1987 Porsche 911 Coupe 109,000 (sold)
1998 Mercedes E300 TurboDiesel 147,000 (sold)
1985 Mercedes 300D 227,000 (totaled by inattentive driver with no insurance!)
1997 Mercedes E300 Diesel 236,000 (sold)
1995 Ducati 900SS (sold)
1987 VW Jetta GLI 157,000 (sold)
1986 Camaro 125,000 (sold - P.O.S.)
1977 Corvette L82 125,000 (sold)
1965 Pontiac GTO 15,000 restored (sold)

My 99-E300TD gets on the average 33 MPG ......I drive 200 mi. a day or more
Check your air filter ...change it every 10 -15000 mi. Fuel filters every 20-30000 mi. ...... A purge with Lubro Molly may help. I run 36 Pounds of air in my tires .....and of course check your speed.
The W/S switch makes a difference (28 on W 33 on S)
Also check to make sure your wheels rotate freely. A sticky Brake caliper can hurt ....Look at the rotors if thy have a mirror finish you have a problem....

Why do you run 36 pounds of air? I run about 28 as called for on the sticker by the fuel cap.

Scott

__________________
Scott
1982 Mercedes 240D, 4 speed, 275,000
1988 Porsche 944 Turbo S (70,000)
1987 Porsche 911 Coupe 109,000 (sold)
1998 Mercedes E300 TurboDiesel 147,000 (sold)
1985 Mercedes 300D 227,000 (totaled by inattentive driver with no insurance!)
1997 Mercedes E300 Diesel 236,000 (sold)
1995 Ducati 900SS (sold)
1987 VW Jetta GLI 157,000 (sold)
1986 Camaro 125,000 (sold - P.O.S.)
1977 Corvette L82 125,000 (sold)
1965 Pontiac GTO 15,000 restored (sold)

I believe adding a few extra pounds should increase your mileage. I run mine at about thirty three or so, a few pounds more than the sticker says.

__________________
Seth

1984 300D 225K
1985 300D Donor body
1985 300D Turbo 165K. Totaled. Donor Engine. It runs!!!
1980 300SD 311K My New Baby.
1979 BMW 633csi 62K+++? Dead odo

It's all about rolling resistance. Plus there are tires that inherently have a lower rolling resistance. Factory number are usually there for comfort.

Here's some info from The TireRack...

must have a 50 tire topics... (nice resource of tire info)
http://www.tirerack.com/about/techcenter.jsp

Lower inflation pressures will allow more deflection as the tire rolls. This will build up more internal heat, increase rolling resistance (causing a reduction in fuel economy of up to 5%) and reduce the tire's tread life by as much as 25% while increasing the probability of irregular treadwear.

A vehicle's fuel economy is the direct result of its total resistance to movement. This includes overcoming inertia (Newton's Law), driveline friction, road grades, tire rolling resistance and air drag.

During stop-and-go city driving, it's estimated that overcoming inertia is responsible for about 35% of the vehicle's resistance. Driveline friction is about 45%; air drag is about 5% and tire rolling resistance is about 15%.

Overcoming inertia no longer plays an appreciable role in the vehicle's resistance during steady speed highway driving. For those conditions it is estimated that driveline friction is about 15%; air drag is about 60% and tire rolling resistance represent about 25%.

If the vehicle equipped with standard Original Equipment low rolling resistance passenger tires normally provided 25 mpg in the city and 30 mpg on the highway, installing tires with 20% greater rolling resistance would only drop fuel mileage by a calculated 3% (to 24.25 mpg) in the city, and a calculated 5% (to 28.5 mpg) on the highway. While this is a measurable difference, it probably isn't much more of an influence on real world fuel economy than being stuck in rush hour traffic a couple of times a week or being stopped at every red light instead of continuing through a string of green lights.

Additionally, the easiest way to reduce rolling resistance to enhance fuel economy is to make certain that the tires are properly inflated. A vehicle that requires its tires to be inflated to 35 psi (based on the vehicle's tire placard) will have an increase in rolling resistance of approximately 12.5% if the tires are allowed to become underinflated to just 28 psi. Therefore, maintaining the vehicle manufacturer's pressure recommended for light load and heavy load conditions may almost be as important as the tires being used.

So, in my thinking upping pressure some probably gains, maybe 1mpg, low rolling resistance tires maybe another 1mpg. Just a thought.

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raMBow

1999 E300DT Obsydian Black Metallic, Heated Full Leather Parchment options, E2, K2, 136,000+, best 36.5 mpg - GP's 12-04 & 11-12 Zero Stuck
2010 Honda Odyssey - The BrideMobile - best 26.5
(2) 2005 Honday Accord- (1 -Corporate 1 - Personal) - 110,000 4-cyl 30mpg
2000 VW Golf GLS TDI, Upsolute Chip (sold to Brother, now 300+k on it) 48.5 mpg like clock work
1987 Honda CRX HF - Sold 87,000 always over 50 mpg Max 67 mpg

Yea...what he said.....

Another update. I increased my tire pressure 6 pounds all the way around. I'm now running 34 psi. On my last tank, I averaged 33.8 mpg. So a combination of using the EC button on the climate control and increasing my tire pressure bumped my mileage up from 28 to almost 34 mpg. Not bad.

Scott

__________________
Scott
1982 Mercedes 240D, 4 speed, 275,000
1988 Porsche 944 Turbo S (70,000)
1987 Porsche 911 Coupe 109,000 (sold)
1998 Mercedes E300 TurboDiesel 147,000 (sold)
1985 Mercedes 300D 227,000 (totaled by inattentive driver with no insurance!)
1997 Mercedes E300 Diesel 236,000 (sold)
1995 Ducati 900SS (sold)
1987 VW Jetta GLI 157,000 (sold)
1986 Camaro 125,000 (sold - P.O.S.)
1977 Corvette L82 125,000 (sold)
1965 Pontiac GTO 15,000 restored (sold)

Great to hear it. I just did a 700 mile run this weekend. Got just a tad over 30 mpg. But that was one day of in town driving and the rest slugging away on the highways/interstates running 70 and 75 mph all the time, plus some back roads with hills. Oh used the AC half the time plus the bride and a bunch of stuff in the car. Wonderful long distance cruiser though. Winter grade B20 probably did not help. And the 30mph winds I was running through all the time.

Did drive over some power lines in the road, debris here and there... keeping out of the 15 tornado sightings in my county. The weather band radio was very nice to track out my strategy for return home. Barely sprinkled on the MB. Company car sitting in driveway, ding city with the golf ball sized hail.

__________________
raMBow

1999 E300DT Obsydian Black Metallic, Heated Full Leather Parchment options, E2, K2, 136,000+, best 36.5 mpg - GP's 12-04 & 11-12 Zero Stuck
2010 Honda Odyssey - The BrideMobile - best 26.5
(2) 2005 Honday Accord- (1 -Corporate 1 - Personal) - 110,000 4-cyl 30mpg
2000 VW Golf GLS TDI, Upsolute Chip (sold to Brother, now 300+k on it) 48.5 mpg like clock work
1987 Honda CRX HF - Sold 87,000 always over 50 mpg Max 67 mpg

I just came back from a trip to florida, with a fully loaded car of five guys and a truck full of luggage, got an amazing 35 mpg an all out best. The first tank outa florida and into alabama and georgia got about 27mpg. As the trip progressed, it got better and better.

__________________
2002 G500 74K
1998 E300 200K and rising
1995 S600 73k


"Some people spend an entire lifetime wondering
if they've made a difference. The Marines don't
have that problem."-Ronald Reagan

"Never tell people how to do things. Tell them
what to do and they will surprise you with their
ingenuity."-General George S. Patton

Hay he is alive! So you took her to FL, I hope they didn't trash it! Why don't you come back to town this weekend I havn't seen you in months!

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

I run the tires on my 300SD around 35-36lbs, I like the feel of it and the improvement in mileage. I just drove about 750 miles this past weekend and I averaged over 26.6 mpg at 75-80mph between the two trips. And it was really windy and rainy on the way back of the second trip (180 miles of it or so) still got over 26. I was getting 19-20 before I replaced my horribly leaky/brittle injecton return lines. Now I leak nothing, and mileage went up 5-6 mpgs!

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

I'm driving a W210 E300TD, UK-spec elegance.

On the motorway (highway), at a steady 75mph, I can easily achieve 40mpg.

The EC switch makes no difference whatsoever to my fuel economy. It was the same on my Audi A4. Some cars are just like that I guess.


I found the easy way to improve economy:

Check diesel spill pipe (underneath intake manifold) isn't leaking
Engine Oil change
Fuel filter change (check pipes for leaks)
Tyre pressure correct

I've just changed the ATF, I'm expecting that to make a difference as well.


The most important thing though is driving habits - accelerate like a lunatic and your mpg will suffer. Accelerate gently, and it will greatly improve.

I can easily get between 450-500 miles on a full tank of diesel, provided all my mileage is on the motorway. Around town in stop-start traffic, its more like 350-450 miles per tank.