Erratic Fuel economy '95 E300D

[lvbizbroker]

I just bought a 1995 E300D with 211,000 miles last week. Car runs well, but I'm getting big fluctuatiuons in fuel economy. First fillup was 33mpg, second fillup was 25.4 mpg, same driving habits. Otherwise, I really like the car. Any ideas?

[connerm]

I've tracked every tank in my e300d for 3 years and I average 29 mpg. Check at fill-ups and over a long period of all kinds of driving.

[Matt L]

The tank on my '96 is small enough that different pumps and even a slight slope to the lot can cause a non-trivial fluctuation in how full you can get the tank.

[TMAllison]

Try to go to the same station and use the same pump for more consistency; that will help rule out user/pump error.

[WINGAS]

I would have to say that if you did have that fluctuation, you would notice it somehow in the manners of the engine. Keep checking it. Was it much warmer outside for your second fullup than the first? Then I'd attribute it to fuel temps causing an early pump shutoff.

[nate300d]

I find a fair bit of variation with mine, but I know that one factor is where I fill up. One place is on a slope and depending which side you are on make a difference in your fill and then another place where I fill it is level, but I have to be careful in filling because it is a pump with to nozzle sizes and a pump fill rate that is very, very fast (it is for trucks).

[equipmentjunkie]

I've had my '95 E300D's tank give a burp and I'd guess that it made a 1/2-gallon difference.

I do something that I am not supposed to do, I fill it up to the top of the neck.

[williamjqmarket]

I have put in excess of 265K of the 410K miles on my 1995 E300. the mileage fell to about 28mpg @ 375K and i started looking into why. After replacing the injectors, replacing the timing chain, replacing all filters as well as the small plastic lines around the pump and filter housing (which develop small leaks over time) and just a general house cleaning exercise under the hood i am back up to an average of ~34mpg. That milage is 80 percent highway @ 75mph. i have seen the fluctuations you are talking about and it is always attributable to how level the car is when i fuel it up. When I use the same pump at the same fuel station i get the same mileage (make one wonder if some pumps are calibrated inaccurately). This has been the most impressive car i have ever owned! 410,000 miles and original alternator, water pump, starter, no transmission work and no rear end work!!!

[bobodaclown]

To even out variations try to fill when its at least 3/4 empty. You'll get more consistent results or least they even out more.

[Hatterasguy]

Make sure you have no fuel leaks and drive it more.

Report back after like 1/2 a dozen tanks.