crappy mileage....

[Gordinho80]

i have not been getting good mileage for the past couple of months now...i am only getting about 330 per tank...that seems unusual for a diesel, even if it weighs as much as mine...

injectors seem good as the engine does not shake and was told that bad injectors would cause engine shaking...

also, ran diesel purge as well as other injector cleaners through and NO difference...

any suggestions???

thanks in advance...
Mario
1993 300D...602 Engine...

[md21722]

Does it smoke? How are your cold starts?

I don't think your winter blend fuel would make more than a 20% difference in fuel economy.

[rickjordan]

Mario, My mileage has also plumeted in the last few weeks. Though I do have problem with the thermostat, it seems to be stuck open. The engine is running 20 deg. cooler and the air through the vents on max is luke warm. What temp. is your engine running at? I also believe aside from that, it's just too darn cold out. I regularly use Power Service winter additive. Hopefully when I get a chance to change out the thermostat, my mileage will improve. Right now with diesel costing about $1.75 a gallon, I need all the help I can get.

[Gordinho80]

thermostat seems to be fine in my car, engine runs normal...no unusual smoke, when i punch it it smokes...cold starts are ok...all in all, car performs and acts like usual just doesnt get the mileage...

thanks...
Mario

[rickjordan]

Are you getting your diesel from the same station every time? Also, are using a winter additive/cetane booster?
Where abouts in NJ are you?

Winterized fuel drops milage by alot, I am getting about 21-23mpg right now in my 300CD, but when running #2 diesel I get 26-28 mpg.

[jassz]

Hi, how long have you had the car? I'm just wondering if you had it last winter, or if you're comparing it to mileage you got in the summer/fall. What I've been told is that there is a big difference in fuel economy between summer and winter with diesels. Maybe even as much as 20%. The engine has to work that much harder, plus we tend to let them 'warm up' more before we even start driving. That said, there may still be ways to improve. There are some hints on the website www.fueleconomy.gov.

Good luck!

Natalie

[Gordinho80]

Are you getting your diesel from the same station every time? Also, are using a winter additive/cetane booster?

Yes, Hess Gas Stations ONLY...Mobil if it is available...but mostly, like 99% Hess...NO additives used, suggestions?...I am from Central Jersey, near East Brunswick, South River...

Hi, how long have you had the car?

I have had the car in MY possesion for nearly 3 years...I have only recently been watching and noticing the little stuff that the car is doing within the last 6 months or so though...before I had the car, my parents drove it from new, back in 93 when they bought it...

thanks all...
Mario

[rickjordan]

For an additive, go to any Walmart and buy Power Service diesel additive. You'll see 2 different colored bottles, gray and white. For winter use you want the white bottle. The other factor in the low fuel economy is the very cold temps. This has been one of the coldest winters in a very long time. So I gather we are just use to warmer temps/better fuel economy. I just wish the temps would go up a bit so that I can change out my thermostat.

[rdanz]

Are there any Agway dealers near you their diesel is 45 cetane and will give you better milage.

[md21722]

If you're running something like Castrol GTX 20w-50 that will hurt you in fuel economy in the cold winter, too. And, if most of your driving is city traffic with frequent cold starts, that will bring down the fuel economy significantly.

[leathermang]

It is not uncommon for a car to get to your mileage and never have the precombustion chambers and the injectors out and cleaned/checked... If carbon finally built up on any of the holes the fuel spray is supposed to come out of it will really make a difference in the efficiency of the fuel burning....

[invisik]

Time to run some Diesel Purge........?

http://www.mindspring.com/~houlihan/merc/purge.htm

-m

[leathermang]

Invisik, He said in the original post that he had used Diesel Purge...with no results... That is why I was suggesting the next deeper step in that area...