New E220 CDI Coupe Poor MPG?

[ede220coupe]

Hi,

I'm getting just 44mpg from a new E220 CDI Coupe from late night 260 mile runs, 99% cruise control at 75mph. I'm pretty disappointed, was expecting around 55mpg based on other diesels on same run.
What figure should I expect? Is this just 'running in'?
I'm having it checked at the dealer this weekend, will update if any issues are found.

Thanks,
Ed

 

[10EDD]

Good name ED! 1,000 miles in and I'm getting circa 50 mpg in similar circumstances, same car/engine, previous expereince is that they lift 10%'ish after 5,000 miles.

Edd

 

[sjmaxwell]

My E220 CDI improved at 1000 miles

 

[Deleted member 37751]

Cruise control will affect your mpg figures negatively, try the same run without using it and I'm sure your figures will improve.

 

[kinaero]

That is pretty poor! I would expect minimum 50mpg even if it has a few hundred miles on it.

 

[flat6buster]

My estate never sees 50 mpg. 30 to 40 on runs under say 20 miles, mid forties on motorway runs. Enormously disappointing when I was getting 60 plus all the time in a rental passat I had whilst waiting for the e to arrive.

 

[The Polisher]

My E220 was getting low 40's when it was new.

Now with 27k on the clock, cruise control at 75mph on long trip it gets to about 48 or 49.

Only seen 50/52 sticking to 65/70mph.

 

[flat6buster]

There you go. Not great really.

 

[ede220coupe]

Hi All, thanks for the comments and advice...

I dropped it off at the local dealer for a check, they updated the software (or possibly just reflashed it; wasn't made totally clear) then they took it it out for a 16 mile run which returned 55mpg. It was mostly A-road with a couple miles of country roads at the end. The average speed was 32mph so I'm guessing they were doing around 55mph on the A-road.
I've since done my usual late night trip from the North East to London, got 49mpg half @75mph the rest @70mph, all with cruise control (sorry I can't give that up!).
It's a definite improvement on the first trip, probably a combination of running in and the software update.
Once I've done a few more trips I'll try a few different fuels, see if there's much difference there.

I'm loving the car btw, very comfortable and still feel fairly relaxed after 4+ hour drives

Cheers,
Ed

 

[E350Matty]

Hey

I'm running new E350 Coupe I'm averaging 36mpg on small runs out hope this gets better.

My first long distance in the car was Leeds to Middlesbrough , I drove all kinds of speeds and roads including some traffic. Could of taken it easier and managed didn't have my eye in the mpg clock either. I was surprised to get a mighty 50.5mpg with only like 150 miles on the clock of the car.

I am very pleased with this and hear that it will get better. But now it's ran in i don't think my mpg will be great anymore, pedal to the metal!!! Haha.

I'm sure you should be getting way more in terms of mpg.

 

[geraldrobins]

May I ask SPK why you think cruise control has a negative effect on fuel consumption. I only turn it off for a short while when its braking on downhill runs.

 

[rf065]

May I ask SPK why you think cruise control has a negative effect on fuel consumption. I only turn it off for a short while when its braking on downhill runs.

Because it's a dumb electronic gizmo that has the sole purpose of keeping you at a fixed speed, it has no conception of saving fuel or economics. The human brain can do the job much better, even though some need more practice than others.

Russ

 

[ashadam]

44mpg Is not bad at all I am averaging 37.4 on a c class.

 

[1chris]

My c class averages 38 as well, I think that is why you pass so many mercedes.......and jaguars, in the slow lane, everybody seems to want to do the mpg mercedes etc claim they do, I don't understand why people buy such a superb car to poodle along at such a slow pace.....beats me, and I am 66 years of age.......so its not an age thing!!

 

[geraldrobins]

I disagree rfo65.
I dont think there is much difference im mpg with or without using cruise, if you drive at a constant speed. If you vary your speed to suit inclines etc than you may have a point. Electronic devices are in fact sometimes better than the human brain such as ABS.

 

[geraldrobins]

1Chris
not sure what you mean by poodling but many people do quite high mileages and fuel cost is important to them. Some people poodle perhaps beaise they already have 9 points on their licences. I drive at 70 incidentally and Im also 66.

 

[grober]

I believe these new injectors all come with individual calibration curves from their manufacturer [ not Mercedes] and have to be programmed to the engine ECU. I suspect some may not be so well calibrated/programmed as others.

 

[rf065]

I disagree rfo65.
I dont think there is much difference im mpg with or without using cruise, if you drive at a constant speed. If you vary your speed to suit inclines etc than you may have a point. Electronic devices are in fact sometimes better than the human brain such as ABS.

Ever used ABS in snow? It takes ages to stop, without ABS you can stop quicker. Another example of an electronic aid that cannot compute anywhere near as much as the human brain. Cruise control is no different.

Russ

 

[gIzzE]

Cruise control is no where near as good as doing it yourself for MPG.

I used to go to Essex a fair bit and the same run in my car with cruise on used to return 39-41mpg every time and take me around 1h20mins.
Doing the same run in 1h20mins with me taking control of the gas would see me getting 45-48mpg every time.

 

[geraldrobins]

gizze and rfo65, Ill have to politely disagree with you based on my experience.
Although I dont have much experience of driving in snow especially emergency braking.
Drove to work without using cruise today and no noticeable difference, although 1 journey is no guide.