1999 E300 - My Worst Fuel Mileage - PeachParts Mercedes-Benz Forum

#1 04-19-2006, 08:56 AM

Last night I filled up my 1999 E300 which my wife drives. I will drive it maybe 20 miles per week. Last night I filled it up (I always fill up the car for my wife) and when I check the mileage it was 23.5. Yuck, this is the worst I have ever seen on this car. This morning I installed a new air filter. I held both filters upto a light, but I could not ready tell much differenct between the two. My wife and I live in the country and work in the same small town and each of use has about a 10-12 mile drive to work. Most of the driving is on straight, flat rural roads, two lane state routes, and a little time at some stop light in town.

With this type of driving I get 25-26 mpg on my 1985 300D. When I bought our 1999 E300 I expected that it would be a little better. I don't expect the EPA rated MPG's that are listed on the stick, but this car has not been what I excpected on fuel economy. My wife drives with a pretty light foot.

What is your MPG on a W210 diesel?

TimFreeh · #2 04-19-2006, 09:02 AM

It's hard to check the mileage on my W210 because it takes forever to get the last 2 gallons in the tank. Of course the owners manual states that you should not fill the tank to the brim so I've only done it a couple of times. I got just over 34MPG on the last check, all highway driving and as I recall the other time I checked it I got over 30 MPG in a mixed mode environment.

I'd check it again, unless your car was operated in 90% stop and go traffic 23 MPG is just absurdly low and I suspect some sort of error was made in your mileage check.

aklim · #3 04-19-2006, 09:45 AM

I drive 80 on the interstates and city driving and am aggressive. I still get about 30 mpg so I think something is wrong with your car.

sokoloff · #4 04-19-2006, 11:00 AM

One check and getting 23 or 34 isn't going to tell you much and is no reason to be elated or deflated. To tell the real mpg you've got to keep it over several tanks and not estimate what you think it is, but actually divide it out. If you get 23 consistently something is wrong. If you get 34 consistently, I want to know what you are doing.

I have records of every gallon of fuel that went into mine over the past six years and I've been as high as 35 and as low as 23, but give no credence to those numbers since I feel they are not accurate for whatever reason. My real average is somewhere in the 28 or 29 area.

Len
'99 E300TD 90,000 miles

deltajetfixer · #5 04-19-2006, 12:17 PM

30-32 mpg mostly highway driving in Atlanta.

I use Powerservice "Diesel Clean+Cetane Boost". I put in 8 ounces of it at every fill-up...$2.65 a gallon for diesel now south of the airport

nhdoc · #6 04-19-2006, 12:58 PM

I've just completed 960 miles on 31 gallons, so just a hair under 31 MPG with a mix of 60/40 highway/city in my '98. Fuel quality and outdoor temps makes a big difference in these, IMHO.

I have also gotten below 25 in the winter around town and over 34 in the summer on 100% highway. My mileage always is 15-20% better in summer than in winter. Overall for the past 15K Miles I would say I have averaged 27± and I did mostly city driving and live in a colder climate than most. The car runs flawlessly otherwise, so I am quite satisfied with the economy.

F18 · #7 04-19-2006, 04:08 PM

Hi Nate,
In 12 miles I think the engine is still in cold start mode and running very rich with the cold weather in OHIO. Also, your vehicle listings indicate that your are running some BioDiesel Blends which will drop your mileage down a couple of points. Even Regular Winter Blend Diesel will also drop mileage a little from Summer Diesel. You need to get out on a Highway and do some long hard running occasionally. You probably have some carbon buildup at the exhaust manifold thats caused the engine to be slightly anemic.... the excess back pressure and reduced air flow is probably making your engine work harder than necessary on your short daily drives.

As some have suggested, run some Diesel Kleen through it. Dump it in your tank and put on a fresh fuel filter filled with it and then get out on the Highway and have some high speed fun for an hour or two.

uberwgn · #8 04-19-2006, 05:35 PM

My father bought a 1998 about 9 months ago. He reports his lifetime MPG at 29.6 which is a big jump up from his SDL. On longer trips he can do mid-30's.

Hatterasguy · #9 04-19-2006, 06:32 PM

Your running B100 according to your sig, expect a drop.

My friend noticed that his mpg's will drop slightly as his fuel filters get old, go figure I can't explain that. But he keeps a fuel log.

#10 04-20-2006, 09:13 AM

Quote:

Originally Posted by Hatterasguy

Your running B100 according to your sig, expect a drop.

The B100 was used from early May to the end of October last year. Since then the car has had only petro diesel. I hope to go to B100 in a month.
I think part of the problem is that my wife makes frequent short trips in town. I did get a little over 29mpg on this car a few months ago in the Indiana turnpike. I had hoped to break 32mpg, but perhaps the winter diesel hurts.

I filled my 1985 300D this morning....364.4 miles / 13.54 gallons=26.9mpg

. I was getting only around 23-24.5 before, but then the weather was colder.

#11 05-30-2006, 09:46 PM

Well, I apologize for troubling all of you of this issue.

The real source has surfaced.......my wife who is the primary driver of this car; she drives this car like it was stolen and then complains about the fuel economy.

I wondered....

Hatterasguy · #12 05-30-2006, 10:47 PM

Doesn't surprise me. Last winter we would um drive my friends around, pretty much sideways...at high rpms...kills mpgs.

Think mid to low 20's. Still not bad considering...

Diesels don't get good mileage at WOT on winter fuel, beleive it or not.

DslBnz · #13 05-30-2006, 11:03 PM

Ha!

There should be a thread for the WORST mileage we've ever witnessed.

Mine was last winter. Around 18 mpg. A few months prior, it was difficult getting below 30.

jfman · #14 05-30-2006, 11:08 PM

Measuring it this way is fool proof because you are measuring the actual gallons you used and comparing them to the miles you drove.

I fill the car up, press the reset button on the cluster and drive the car to my destination. Then when I get there. I fill the car back up. I look at how many gallons I now just put in. I look at the miles on the trip odometer.

Miles on trip /Gallons just put in = MPG

Hatterasguy · #15 05-30-2006, 11:10 PM

The problem with doing that is unless you fill that tank up right to the cap, your readings will be off. Different pumps cut out at different times.

Plus fuel mileage needs to be averaged to get meaningfull numbers. Like average your tanks for a year, then you get a good picture.