I recently bought a 98 E300 TD and drove it cross-county from the dealer. With 100% highway miles, I was getting 27mpg at best. Now, with a mix of city/highway, I get around 25mpg. I was expecting mileage in the mid 30's. I like the car, but when diesel costs more than premium, I'd be spending less per mile with V8 gasoline engine. Any ideas on what could be wrong?

I have the same year and model and get almost the same mileage. Mid to upper 20's with mixed driving and high 20's with highway miles. The best I have gotten is just under 29 since I have had mine (2 months). Maybe in the warm weather with summer fuel we'll see low 30's on the highway. I think the 37 MPG everyone throws around is just a myth. Look on the bright side, when the summer fuels start coming in the prices have historically dropped...so you'll be paying no more for Diesel than premium, maybe less, then you will still see 20-30% better economy than with the E320.

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

No way!! At 85 mph (in theory, never did it) on the highway, I get about 31 and in the city I get about 26. This is with a 99 E300 and I don't spare the accelerator pedal. I never do an italian tune up monthly because I do it several times daily, in theory tho. This is with my 200# ass and the wife at 100# too. No cargo and tires are at spec pressure.

__________________
01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

According to the EPA website the '98 is rated at 26 city 34 highway and 30 combined while the '99 is rated at 26 city and 36 highway with 30 combined. The E320 in '98 is rated at 20/26 and in '99 20/28. I don't know if the '99 transmission is different or if the EPA tests were just changed for '99 to explain the difference on the highway ratings but it would seem possible that if, for example, the final gear ratio were different on the '99 it would explain why you get 31 in your '99 and we only get high 20's in our '98s.

Now, I wish I could understand why none of us sees anywhere near the mid 30's the EPA estimates for highway mileage. I don't go 85, more like 70-75 on the highway and that's the tank I got nearly 29 on with 75% highway driving. So, maybe on that tank I broke 30 on the highway but no way was it 34.

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

Today, I filled up. I got 715km out of 68 L of diesel. Thats like 9.5L/100km

Car is a 95 E300D, Non turbo OM606

If my engineering is correct that's a hair under 25MPG (24.88), so even less than ours.

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

Right around 30 highway and high 20's MPG is my expereince also with 98 E300 TD - love the car but 37MPG seems to be a myth in my book too.

Right around 30 highway and high 20's MPG in mixed driving is my expereince also with 98 E300 TD - love the car but 37MPG seems to be a myth in my book too.

27mpg on a tank of city/highway and alot of full-throttle expirimentation. The car isn't running right yet so I think 30+ highway is definately do-able.

i wish my chevy would see 25 mpg. dang - it it saw 15 or higher i would jump for joy. my truck currently rocks about 10 or 11 mpg. not short on power, but other wise forget it, i'll drive the benz and fill up once a week.

__________________
1979 Thistle Green 300D 272,xxx miles
1984 Orient Red 300 D 4 spd Euro Import - 189,xxx miles
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Lofat Productions
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Yes, that sounds right, I am little dissapointed as well. However the temperatures are still low in the morning so it takes more to for the engine to get to operating temp. Also the car isnt driven at economical speeds.

I think my best was 28 MPG when I did 50% hwy and 50% city last summer with a heavy foot.

Well you may want to do some things that could be of help to your car...like changing out fuel filters, air filterscleaning out your diesel tank..diesel purge...adding some Diesel additive etc..... and you may have already done this, but it's a thought. You know Diesel maybe higher right now and that's generally the case in the winter especially in the north when more heating oil is burned. We also seem to have more of a colder spring than normal. Diesel Fuel prices should lower in the summer. I must add that your Diesel Engine will peform just as good as a V-8 gasoline engine will if it's properly maintained. I might add by the way that there's nothing like the sound of that Diesel Engine doing a little clattering under the hood.

Low 30's on the highway at normal speeds (60-80) is what you should be getting.

How much stuff do you keep in your car? How clean is your air filter? Any other problems?

__________________
2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

I don't carry anything around in the car. Well, its good to know its not too unusual to be below the range, but I still don't understand how the car could fool the EPA for their ratings test.

Go here, my friend.

http://www.epa.gov/otaq/cert/dearmfr/gasmel.pdf
ADOBE ACROBAT PDF FILE

The cars ride the rollers.

Hmm,..Diesel engine physics?

__________________
1987 300SDL (324000)

1986 Porsche 951 (944 Turbo) (166000)

1978 Porsche 924 (99000)

1996 Nissan Pathfinder R50 (201000)