poor fuel economy on E320 CDI

[Satch]

Satch - are you sure, I thought W211 cabin heaters were fuel driven not ceramic / electric.

There are optional fuel driven Aux. heaters available in some cold climate markets but what I have is an electric PTC (Positive Temperature Coefficient) heater. T

These are useful on a diesel (which takes a while to produce enough heat in cold weather to warm the cabin) as they have near instant and variable heat production, are small, light and a damn sight cheaper than a fuel powered system.

 

[Rory]

We've discussed this before, but I don't think anyone was very sure how this system works.

My late 2004 W203 270CDi has cluster options for booster heater: off, off with a/c off, auto. If I recall correctly is works if the temp is less than 8C.

I *thought* that it used the a/c compressor in reverse as a heat pump type thing?

I've always leave mine in auto, but, compared to other diesels I've driven, I wouldn't say it makes an obvious difference.

I'm sure it's not cermamic heater - I drove an A Class with that recently and it was blowing warm air within 200yds. Amazing.

 

[DieselE]

Rory. The W203 system is not the same as that on the W211. On the E320CDI, the standard system is as described by Satch. It's not an auxiliary heater, that's an optional extra.

 

[Satch]

A class CDi models are also fitted with PTC heaters.

They are very common devices now and found in all manner of places.

http://www.epcos.com/web/generator/Web/Sections/Components/Page,locale=en,r=263282,a=372328.html

 

[BTB 500]

Didn't think my Vito had any kind of booster/auxiliary heater, but you do get warm air in the cabin pretty quickly in cold weather??

 

[Rory]

Rory. The W203 system is not the same as that on the W211. On the E320CDI, the standard system is as described by Satch. It's not an auxiliary heater, that's an optional extra.

I used the term auxiliary in error in my earlier post, corrected later to "booster".

My car has the "booster" function, selectable in the cluster display. I don't have the auxiliary heater - it's shown in the handbook as optional equipment but isn't listed in the brochure price list that I have from when the car was new.

I'm really not sure how the booster works - I had it my head it was the a/c compressor running as a heat pump, but I might be confusing that with the Honda Diesel. It's not a PTC heater - or it is, then it's not working. Last option would be electric heater in the water system, as some Ford's use.

 

[glojo]

Don't forget the author has an EU4 3ltr V6 diesel which is a completely different beast to the older 3.2ltr straight six. Short journeys around town will knocck a huge hole in fuel consumption figures, and in fairness this type of motoring is also uneconomic on petrol powered beasts As has already been stated, a 3ltr vehicle is not very fuel efficient for town driving.

We are lucky to see a 30mpg average but to be perfecty honest, it is to be expected. Short town journeys over very hilly terrain helps make the chancellor a very happy person.

 

[greyboy]

I have a 2001 E320 CDi estate. I get about 460 - 470 miles on a tank, full to yellow light on, which is approx 35 mpg. The fuel computer readout seems to be rather optimistic as it can go up to 42 mpg on a run. I am more than happy with these figures as it is a very big, heavy car. Took the family on holiday to Cornwall last week, 5 of us plus the back loaded to the roof and still got the same mileage from a tankful. Motorway driving and touring around Cornwall.

 

[1NDYT]

I bought a 53 E320Cdi Estate a few months ago and it seem to be averaging 33MPG with mostly motorway mileage. I cover about 60miles per day.

However, mine does have 18inch wheels with 265width on rear and 245width on the front but i still would have expected average to be about high 30's. It's not like i floor it everywhere i go so i would have expected it to be better.

One thing i have noticed is that my car seems to run at a maximum of 60C and rarely reaches 90C. We also have E280CDI with 7G which easily averages 39-41 on motorway and gets to 90C alot quicker.

Any clues as to why running temperature remains low...even with the weather we've had today?

 

[Dieselman]

Any clues as to why running temperature remains low...even with the weather we've had today?

Needs new thermostat.

 

[1NDYT]

Is that an easy job to do or one for the garage?
Would you know how much these Thermostats cost?

.....and would better running temp improve fuel consumption?

 

[Dieselman]

Easy job, just unbolts after draining the radiator.

It should hopefully improve fuel ECONOMY, not consumption..

 

[television]

Actually you only need to drain half unless you want to change the coolant at ther same time

41 in the link
http://www.detali.ru/cat/oem_mb2.as...GA=722.626&CT=M&cat=65C&SID=20&SGR=015&SGN=01

 

[effbee584]

E320cdi (2003 in line 6 Euro 3?) Computer shows 36.8 over last 4500 miles, town and country. On two trips to Italy, 2500 miles door to door, averaged 40.3 and 40.1, not bad cruising at 85ish for hours fully loaded with aircon on.

 

[renault12ts]

E320cdi (2003 in line 6 Euro 3?) Computer shows 36.8 over last 4500 miles, town and country. On two trips to Italy, 2500 miles door to door, averaged 40.3 and 40.1, not bad cruising at 85ish for hours fully loaded with aircon on.

That's what the computer shows...what was the reality? I've seen over 50mpg...but not in reality.

 

[rothbury]

E320cdi (2003 in line 6 Euro 3?) Computer shows 36.8 over last 4500 miles, town and country. On two trips to Italy, 2500 miles door to door, averaged 40.3 and 40.1, not bad cruising at 85ish for hours fully loaded with aircon on.

The higher the euro rating the higher the consumption! The W211 euro 4 can't compete with the W210 consumption wise.

 

[SL300-24]

I get about the same as the OP from my V6 320CDI. My old 2003 car with the IL6 was definately more economical.....

 

[Rorcus]

mine around town is only 21 - 24mpg at best.. only had her a couple of weeks now.. I'm kinda hoping it's because my thermostat is fubar'd and the engine is sitting at 40-50c most of the time. (Thermostat has arrived now and will change it over at the weekend)

 

[bigbanger]

Old thread revival and a bit off topic!My old W210 E320CDi trip computer regularly shows 40+mpg but I find in reality it does 36-37 mpg which I'm happy with.

 

[fah320]

Well with my w210 i have never seen 50mpg not even driving at 50mph with the air con and everything else off

With the cold weather i'm seing 4-6 mpg less than in summer and mine was noticably better on fuel after it had done 20,000miles

I have seen 54,35 with mine with constant 56mph in 50 miles with a/c off. But this is the computer readout, actual would be around 10% more....