83 240d huge mileage decrease when freezing
02-05-2011, 06:38 AM
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83 240D
83 240d huge mileage decrease when freezing
I have an 83 240D with 230k miles. I've been the owner since may of 2010. During summer and fall, I averaged 25-28MPG. When winter hit and the temp started dropping into the low 50's and 40's I noticed the mileage went down to the low 20's and high teens. Just during the past few weeks in Oklahoma, where I live, the temp has been down to near zero during the times I would be driving. The mileage is now decreased to a mere 15.7 MPG! The Mercedes owner manual states that lower ambient temps will cause a drop in mileage. But to decrease it by 10 MPG seems fairly extreme to me. But again, I am no expert. Has anyone experienced the same issue I am having? I am trying to figure out if this is a normal thing for high mileage Mercedes diesels when its freezing, or if there is another cause I am overlooking.
I do NOT use synthetic oil. I have solid compression on all cylinders, does not smoke, I've checked all lines and fittings for fuel leaks and found none, it is very easy to start even without a block heater, all filters are new, same driving habit, all tires age good and aired up. Since it has been freezing, I have added Power Services anti gelling cetane boost additive to the diesel.
Any information would be greatly appreciated! Thanks!
I do NOT use synthetic oil. I have solid compression on all cylinders, does not smoke, I've checked all lines and fittings for fuel leaks and found none, it is very easy to start even without a block heater, all filters are new, same driving habit, all tires age good and aired up. Since it has been freezing, I have added Power Services anti gelling cetane boost additive to the diesel.
Any information would be greatly appreciated! Thanks!
02-06-2011, 04:10 PM
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2006 E320 CDI 235 hp 420 ft tq
Winter fuel will get you about 10% less mpg's and with the cold it will go down even more I filled my CDI up and got 19 mpg from my 25 to 26 mpg in town.
And the oil 15w40 is going to take a very long time to warm up and all the time its not at operating temp there is going to drag the motor trying to run.
And the oil 15w40 is going to take a very long time to warm up and all the time its not at operating temp there is going to drag the motor trying to run.
02-07-2011, 01:30 AM
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I would imagine that if the vehicle was pushing through snow it would increase fuel consumption.
One consideration is whether your engine coolant thermostat is working correctly ?.Is the engine running at the normal operating temp?.
In the old old days ! you could regulate the radiator air flow with manually adjustable louvers!.
One consideration is whether your engine coolant thermostat is working correctly ?.Is the engine running at the normal operating temp?.
In the old old days ! you could regulate the radiator air flow with manually adjustable louvers!.
02-07-2011, 09:20 AM
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1982 300D VNT, 1980 240D 3.0T, 1982 300TD
Anything below 20mpg means there is an active fuel leak.
Even if you flog the **** out of your car, a 240D has no excuse to go below that.
Even if you flog the **** out of your car, a 240D has no excuse to go below that.
02-07-2011, 12:36 PM
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When temperatures go down your diesel fuel gets thicker, that means more fuel gets injected than if it was warmer. Later manufacturers incorporated fuel temperature sensors to help calculate the fuel more precisely.
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02-10-2011, 09:16 AM
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Does diesel fuel get thicker in cold temperatures?
What is a pupose of FTS on a Computer controlled diesel engine?
I used GE page just for the explanation of the sensor, you added nothing.
The OP said that there are no leaks, yet , you insist that there are just because you said so?
Op asked for any pertinent information, I provided some and you say I'm trolling?
02-10-2011, 02:32 PM
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OP:
From what I have experienced, during winter, mileage will drop significantly. Had a Dodge Ram 2500 with the Cummins TD, and this ML and they both dropped MPG's in winter.
Seems like you have checked all probable culprits, so I would say that your fuel station may be using a blend of diesel diluted with more anti gell added. That would mean more fuel have to be injected to give the same equivalent power as the "summer diesel".
Also, do you start and idle the car to run the heater before you drive in the mornings for defrosting and comfort etc.? That could skew your mileage calculations to the downside. On my CDI, if I let it warm up even for 5 minutes in my driveway, my daily commute milieage drops 3-6MPG for the same style drive.
I know you say your getting a +-10MPG drop, but if a computerized CDI turbodiesel drops 3-6, then I see no reason why an older mechanical injection system shouldnt be a little more off.
Let us know what you find.
From what I have experienced, during winter, mileage will drop significantly. Had a Dodge Ram 2500 with the Cummins TD, and this ML and they both dropped MPG's in winter.
Seems like you have checked all probable culprits, so I would say that your fuel station may be using a blend of diesel diluted with more anti gell added. That would mean more fuel have to be injected to give the same equivalent power as the "summer diesel".
Also, do you start and idle the car to run the heater before you drive in the mornings for defrosting and comfort etc.? That could skew your mileage calculations to the downside. On my CDI, if I let it warm up even for 5 minutes in my driveway, my daily commute milieage drops 3-6MPG for the same style drive.
I know you say your getting a +-10MPG drop, but if a computerized CDI turbodiesel drops 3-6, then I see no reason why an older mechanical injection system shouldnt be a little more off.
Let us know what you find.
02-14-2011, 10:49 AM
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6.6 LBZ Dmax
I have an 83 240D with 230k miles. I've been the owner since may of 2010. During summer and fall, I averaged 25-28MPG. When winter hit and the temp started dropping into the low 50's and 40's I noticed the mileage went down to the low 20's and high teens. Just during the past few weeks in Oklahoma, where I live, the temp has been down to near zero during the times I would be driving. The mileage is now decreased to a mere 15.7 MPG! The Mercedes owner manual states that lower ambient temps will cause a drop in mileage. But to decrease it by 10 MPG seems fairly extreme to me. But again, I am no expert. Has anyone experienced the same issue I am having? I am trying to figure out if this is a normal thing for high mileage Mercedes diesels when its freezing, or if there is another cause I am overlooking.
I do NOT use synthetic oil. I have solid compression on all cylinders, does not smoke, I've checked all lines and fittings for fuel leaks and found none, it is very easy to start even without a block heater, all filters are new, same driving habit, all tires age good and aired up. Since it has been freezing, I have added Power Services anti gelling cetane boost additive to the diesel.
Any information would be greatly appreciated! Thanks!
I do NOT use synthetic oil. I have solid compression on all cylinders, does not smoke, I've checked all lines and fittings for fuel leaks and found none, it is very easy to start even without a block heater, all filters are new, same driving habit, all tires age good and aired up. Since it has been freezing, I have added Power Services anti gelling cetane boost additive to the diesel.
Any information would be greatly appreciated! Thanks!
http://www.lcbamarketing.com/why_die...y_drops_in.htm
02-28-2011, 09:14 AM
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I understand that you want to voice your opinion here, but there is a standard in a conversation. When you disagree with someone over stated comments, you show proof of where that person is incorrect and then that person either responds with aha or ohh.
So far you have not produced any info to contradict what is being discussed, you simply said that it's "wrong" and that is it?
So far you have not produced any info to contradict what is being discussed, you simply said that it's "wrong" and that is it?
