E350 Coupe Economy (or lack of!)

[Telxxl]

Am I missing a trick here guys? When I bought the car I was under the impression it would be more economical than my 3.0 tdi quattro Audi. The Audi used to return me between 29-30 mpg (mixed driving) and I drove it hard. Over a 2 week period testing the 350 coupe and if I am honest not driving it as hard I am getting a paltry 21.6 mpg! Any ideas greatly appreciated

 

[GreetMe]

What kind of driving are you doing? Town, motorway, B roads?

I've found that big engines return the worst MPG in stop-start traffic rather than flat-out driving.

I've owned a couple of V6s (2.7 twin-turbo and 3.2 NA) and the E55 is my third V8 and they've all delivered rubbish MPG in traffic.

 

[Telxxl]

Mainly town and B roads but nothing different to the Audi.

 

[GreetMe]

What's the official figure? I'd guess about 35-40 MPG.

Your average is only slightly higher than I'm getting from my E55 so there's definitely something up.

Is there anywhere nearby with a Star system to diagnose the problem?

 

[Telxxl]

It should be circa 37 MPG. Is it worth me taking it to the local MB stealer and asking them to check? I am planning a remap which may cure this but would like any problems diagnosed first.

 

[Seamster15]

How many miles has the car done? Most cars don't start to return decent mpg figures for a fair few thousand miles.

 

[Deleted member 37751]

Is this E350 petrol or diesel?

 

[GreetMe]

Is this E350 petrol or diesel?

I wondered that too so I checked his other posts. It's an E350 CDi coupe.

http://www.mbclub.co.uk/forums/engine/130429-e350-cdi-blue-efficency-remap.html

 

[GreetMe]

It should be circa 37 MPG. Is it worth me taking it to the local MB stealer and asking them to check? I am planning a remap which may cure this but would like any problems diagnosed first.

I would say take it to an independent with Star rather than Mercedes but if that's your only option then, yes.

Alternatively, if you already know where you're getting the remap done, ask them to have a look.

I'd want this sorted before doing any modifications.

 

[Telxxl]

Sorry guys it's a Diesel just covered 20k. I believe there is a independent STAR garage in Ruislip which isn't too far.

 

[Deleted member 37751]

I wondered that too so I checked his other posts. It's an E350 CDi coupe.

I've been getting 42mpg driving local and over 50mpg on the motorway in this E350 CDi (265).

 

[Telxxl]

I've been getting 42mpg driving local and over 50mpg on the motorway in this E350 CDi (265).

Ouch ok something not right!

 

[Deleted member 37751]

Ouch ok something not right!

The car has 7k on the clock, just out of interest.

The iPhone app isn't working for the forum, otherwise I'd post a picture.

Take a look at my thread 'a W211 owners view on a W212' and there's a photo of the trip computer on there.

 

[Dr-Nab]

I get 30-35 around town in mine, 45+ on longer runs could be down to how you use the throttle though if you're kind of heavy footed with them the economy drops off.. massively.. another question though how long are your journeys and does the car properly warm up for them?

 

[Telxxl]

I maybe hard on the throttle (I have installed a sprint booster to overcome the throttle delay) but again this is no different to the Audi, same goes for the warm up.

 

[wilsodg]

I have an E350 Estate and it's averaged about 30mpg over 10k miles.
You have to be doing long runs to get anything reasonable - it doesn't warm up properly for about 15 miles. I see reports of people getting 50mpg but I don't understand that because if I sit at a steady 60mph on a flat motorway for an hour then my OBC says low 40's. I come to the conclusion that there must be quite a difference between engines.

21mpg is low - even if I am really reckless round the lanes then the consumption only goes down to about 24. I have put mine back to the dealer a couple of times, and there are some software updates to the Engine Management and the Fuel Pump. They applied the latest update last week and that seems to have improved consumption by 2 mpg. I wouldn't go for a remap until it is sorted. My Brabus box seems to have reduced mpg by 1 - 2.

 

[developer]

I have an E350 Estate and it's averaged about 30mpg over 10k miles.
You have to be doing long runs to get anything reasonable - it doesn't warm up properly for about 15 miles. I see reports of people getting 50mpg but I don't understand that because if I sit at a steady 60mph on a flat motorway for an hour then my OBC says low 40's. I come to the conclusion that there must be quite a difference between engines.

21mpg is low - even if I am really reckless round the lanes then the consumption only goes down to about 24. I have put mine back to the dealer a couple of times, and there are some software updates to the Engine Management and the Fuel Pump. They applied the latest update last week and that seems to have improved consumption by 2 mpg. I wouldn't go for a remap until it is sorted. My Brabus box seems to have reduced mpg by 1 - 2.

I'd be very interested in a report about the D6S - nobody has reported back as far as I'm aware.
Perhaps a new thread to avoid a hijack.

 

[wilsodg]

I maybe hard on the throttle (I have installed a sprint booster to overcome the throttle delay) .

According to the SprintBooster web site,
" Sprint Booster modifies the signal between the accelerator pedal module and the electronic throttle body. This modified signal forces the throttle body to open 'more' than the stock signal at a given pedal position. In effect, the idle-to-full-throttle pedal travel is reduced".

I wonder if this is part of the issue. A few of us comment that you have to be really gentle with the throttle on this engine - I find I have to almost caress it gently with my foot to get any kind of economy and the SB is effectively sticking an electronically assisted lead boot on your right foot.

The SB is apparently plug'n-play - maybe unplug it for a tank and see what difference it makes?