2006 E320 CDI - bad city mileage?

[Diesel Benz]

I guess it is OK to suggest other cars for the OP but if he claims his driving style and the faced city traffic have always given EPA figures or better with other cars, I don't see why that would not be the case with the W211. City mileage is really difficult to comment as mentioned above but the comparison with other cars puts this a bit on a scale.

There are several issues that kill the CDI fuel efficiency, one typical issue is the thermostat. The engine needs to reach normal temperature (about 90 degrees Celsius), otherwise it will consume a lot more fuel. Then all the exhaust and intake emissions systems etc. have to work properly. Injectors must be good etc. etc. Unfortunately I've seen from other forums that workshops are not always good in diagnosing fuel consumption issues, obvious fault codes may not be present.

[unitfreebie]

My old 1982 300SD never got better than 20 mpg in the hilly streets of San Francisco.... but got almost 27 mpg on the Hiway for an average of 24 mpg overall!!

[nopcbs]

The original EPA city estimate for the 2006 E320 CDI was 27 mpg. This went down a shocking 4 mpg on the revised estimate they post now...to 23 mpg.

When I was first shopping for a diesel earlier this year, I was focusing on a Jetta TDI wagon, a new one. In my on-line research I found many Jetta owners who were complaining about how the EPA estimates were way too low. This appeared to be true as one person supplied a link to an EPA web site where they admitted that they were underestimating diesel car mileage...which was surprising. CR in testing a Jetta TDI, recently, got high 20's city and 47 mpg highway. The highway number was almost 10 mpg better than the EPA estimate. Their city number was, as I recall, also better.

When EPA revised their fudge factoring system this year I suspect a big part of the need was because of the ethanol the feds are putting into gasoline now that lowers mileage for gas cars. I think diesels were just carried along in the effort.

- GRL

Originally Posted by Diesel Benz

I guess it is OK to suggest other cars for the OP but if he claims his driving style and the faced city traffic have always given EPA figures or better with other cars, I don't see why that would not be the case with the W211. City mileage is really difficult to comment as mentioned above but the comparison with other cars puts this a bit on a scale.

There are several issues that kill the CDI fuel efficiency, one typical issue is the thermostat. The engine needs to reach normal temperature (about 90 degrees Celsius), otherwise it will consume a lot more fuel. Then all the exhaust and intake emissions systems etc. have to work properly. Injectors must be good etc. etc. Unfortunately I've seen from other forums that workshops are not always good in diagnosing fuel consumption issues, obvious fault codes may not be present.

[unitfreebie]

Hey GRL,

The Jetta TDI and MBZ CDI are two completely different (except for the Diesel engines) cars !!! The market being target is different too.

Your Mercedes is a solid Hi-Tech Design and Built car that is a marvel of engineering... The rides of both cars are completely different... you have complete comfort and luxury in the Mercedes with a Timeless style that cannot be said for some other cars.

However, check out what was said about the injection/exhaust system and just Enjoy the ride!

[Kajtek1]

I really can't believe what I am seeing. 13 replies about defective car and/or defective driver based on 10 gallons refill?
Even 1 full tank refill recalculated shouldn't be taken as an average mpg.
With 2% sloping driveway the fill up can be different by as much as 2 gallons, so on 10 gallons fill the error can be 20%.
So what if on next fill up you will calculate 28 mpg?
I don't know if the high mileage E320cdi that I already sold was exception, but I had no problem getting 40 mpg on long cruises even at high speeds. Unfortunately California freeway blockers alone could take 25 % of it quite easly.

[nopcbs]

I don't want to get into a VW vs. MB thing,but...

A new Jetta TDI wagon would have cost just a little less than the 2006 MB E320 CDI that I bought. Both came with 4 years of warranty. Neither is really a sports sedan. Both have iffy reliability, typical (alas) of German cars. One is a sedan, one is a wagon. Both are plenty roomy and both have nice interiors with good plastics. Both have vinyl seats (the Merc has some leather). The Merc has wood trim and a wood-trimmed steering wheel (which I promptly put a Wheelskins leather glove on), while the Jetta has a leather steering wheel cover standard. The Jetta is definitely down on power vs. the CDI, but it is not bad. They are both very nice sedans. If the E320 was new and $50,000+, no way would it be it worth that in comparison with the $30,000 cost of a new loaded up Jetta.

They are not the same thing, but not as different in terms of driving and comfort as you make out. I drove Jettas three times (manual and wagon) and they are as nice cars to drive and ride in as the E320 I ended up buying. Before you dismiss the Jetta, you should go drive one.

It was almost a coin toss as to which to get, but in the end I decided to try the E320 (my first Merc after a couple of Lexi and a BMW). A key point was that I thought I could get something like 27 mpg city and 37 mpg highway (old EPA estimate and pronouncements by owners in this discussion group and others). I'm not far off on the highway number, but way down on city.

I'm ending up liking the car and don't regret buying it at all; it's a pleasant car and the Honda Accord-like profile and white color make it blend in nicely on a parking lot ( agood thing as flash cars seem to attract shopping carts and key-artists), but the much worse than anticipated city mileage does gnaw at me. Hence my original question about what other folks with CDI's are getting. I want data to decide if mine needs to be looked at by the local (60 miles away) dealer before I invest the time in the long drive out.

Now, I am going to annoy some people with the following, but as for this "complete comfort and luxury in the Mercedes" thing, you definitely need to go test drive a Lexus LS or GS series car (new or used) and it really does not matter how old it is. As to "comfort and luxury" our 1992 LS400 just blows away the 2006 E320. No question. The ES320 is a better handler, but for luxury, it loses...and that's OK with me as I fully expected it and am not all that much into "comfort and luxury", anyway, beyond a reasonable point.

- GRL

Originally Posted by unitfreebie

Hey GRL,

The Jetta TDI and MBZ CDI are two completely different (except for the Diesel engines) cars !!! The market being target is different too.

Your Mercedes is a solid Hi-Tech Design and Built car that is a marvel of engineering... The rides of both cars are completely different... you have complete comfort and luxury in the Mercedes with a Timeless style that cannot be said for some other cars.

However, check out what was said about the injection/exhaust system and just Enjoy the ride!

[nopcbs]

I only brought up the Jetta, initially, beacuse Jetta owners were reporting FAR HIGHER mileage numbers than the EPA estimate...and CR confirmed that. This also led to the EPA web site point about them admitting they were under-rating the mpg of diesels with the new system. My point is that I am getting LESS than the new EPA estimate which is out of line with the above observations.

I was not proposing that YOU compare a Jetta with a MB...although I, personally, did for my own reasons.

Originally Posted by unitfreebie

Hey GRL,

The Jetta TDI and MBZ CDI are two completely different (except for the Diesel engines) cars !!! The market being target is different too.

Your Mercedes is a solid Hi-Tech Design and Built car that is a marvel of engineering... The rides of both cars are completely different... you have complete comfort and luxury in the Mercedes with a Timeless style that cannot be said for some other cars.

However, check out what was said about the injection/exhaust system and just Enjoy the ride!

[Kajtek1]

I drove 2003 Jetta tdi and I drove 2005 E320cdi.
They averaged the same mpg and I have 500 miles route that I routinely drive with the same conditions.
Than the 201 HP in Mercedes gave me better accelerations than 90 HP in Jetta and MB was handling grades better (although I made Grapevine at 80 mph in Jetta as well), so I was covering the distance faster. In conclusion MB was offering better economy.
Purchase price wasn't that much different, so considering very expensive oil Jetta required and very expensive timing belt I would have to do -the MB on long run would come cheaper to me.
Since we don't need daily driver I decided to keep 99 E300td. That thing after using it for 3 years is still sellable for close to what I paid for it.

[aeubank]

Nopcbs.

You seem to be happy and content running the SAME issue into the ground. I enjoy a good debate but you have to admit, this is getting pretty old. It may be a good idea to go to the dealership and let them tell you that nothing's wrong with your car. I for one don't see your issue of how your other cars compared to the e320 and only had a 10% difference in mileage. Keep in mind that an 330i is about the same size as a Nissan Sentra. Nothing wrong with that, but maybe you're a little too regimented and stuck on the numbers to feel that the MB is worth the cost and issues you seem to be having..


Just thinking out loud, but IMO if you're spending all of your time typing this on a forum instead of going to a dealer for some possible investigation you will probably never get a satisfactory answer. My recommendation of the Toyota dealer still stands. You might meet quite a few folks there with similar mileage issues..

[mescaline]

I never get mpg people claim on this forum either, in fact i get a lot worse mileage but well...i also have DPF which apparently kills mileage by a lot. I just went to a very long trip and my wife got 7.5L/100km out of it...while i drove a lot faster and got 8.4L/100km or so...then on autobahn i drove like 180km/h to 210km/h constantly and got around 9.2L/100km

In pure city traffic I get around 9-10L/100km, depends on how many traffic lights catch me..but anyway I also have huge 19'' wheels with 275 wide tires in back and 245 in front, the best i ever got out of this car is when my wife babied it once... 6.5L/100km, i don't think it's possible to go under this