C300 Fuel Economy

Jasandjules

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C300 Estate (s205)
I may be optimistic, however the Parkers MPG figures are about 68 for my C300 AMG Line. But my last tank I got 43mpg average. Now even if I take 10-15mpg off the 68 I would expect to get over 50mpg. I am not flooring it everywhere either.... Even on a run the other day the computer said 47 mpg..

Anyone get anywhere near the claimed figures? (yes I know the weather is colder too)
 

th3h1ghlander

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CLS 350cdi (C218) 2012 / OM642
I may be optimistic, however the Parkers MPG figures are about 68 for my C300 AMG Line. But my last tank I got 43mpg average. Now even if I take 10-15mpg off the 68 I would expect to get over 50mpg. I am not flooring it everywhere either.... Even on a run the other day the computer said 47 mpg..

Anyone get anywhere near the claimed figures? (yes I know the weather is colder too)

I know I have a vastly different model and engine, having a 2002 C270 cdi, however parkers say I should get 39mpg. Assuming this is combined urban/extra, for me this is accurate as I tend to get 38-40 combined. I know I have read that 33MPG urban and 50MPG extra-urban figures for my model, I hit 53.4MPG on the dash computer on a 70/50mph 200mile M1 run southbound on Sunday night (I was driving very gently, barely accelerating when speeding up).

68MPG sounds very optimistic?! What config do you have for your C300? Can you post the parkers page link you are looking at? I would have expected a max a lot lower than that.


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John Laidlaw

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Land Rover Discovery 4
I had the E300 Diesel Hybrid which I think is the same engine as yours? Presuming so I used to get 55-58 MPG regularly and on some occasions on the right roads c65MPG.
I did get into a real eco mode with that car, always trying to beat the best I’d previously achieved...
These figures were summer, you could knock 5-7 MPG off for winter.
That nonsense thinking has gone on my part now....;)
 

bembo449

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the figures in books like this are never real world ! all manufacturer MPG claims are done on a test bed not with a car , out on the road actually driving
 
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Jasandjules

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C300 Estate (s205)
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Yes, quite odd when you pull out of a parking space under battery power..... BUT whilst the Parkers MPG are not real world I would expect to get 10-15mpg under it at worst, not 25 !! IF I got 60 on a run I would be more than happy, but 47 out of a tank is not good considering....
 

th3h1ghlander

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CLS 350cdi (C218) 2012 / OM642
Yes, quite odd when you pull out of a parking space under battery power..... BUT whilst the Parkers MPG are not real world I would expect to get 10-15mpg under it at worst, not 25 !! IF I got 60 on a run I would be more than happy, but 47 out of a tank is not good considering....

So it could be the way you are measuring it and driving? Perhaps reset the MPG trip counter, after the car has idled to warm (if possible to take out of hybrid mode to get the engine going, if not, drive around the block first), just before you are about to drive away, then accelerate very gently, get on the motorway/dual carriageway for at least 30min at a constant speed so that it has a chance to register then you can check consumption at that point, then reset again and continue to monitor at constant speed for another 30mins, then compare as you will have both combined and extra urban figures. Given the year of your vehicle and engine type/size I would expect you to see in the mid to high 50s?


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John Laidlaw

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On a run certainly I got mid to high 50’s - have you mastered ‘sailing’ mode yet ;)
 

th3h1ghlander

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On a run certainly I got mid to high 50’s - have you mastered ‘sailing’ mode yet ;)

Post your sailing technique. I far prefer wafting to sailing but it is not great for fuel consumption ;)


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John Laidlaw

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In hybrids....when on a motorway , either downhill slope or level when at cruising speeds lift off and watch the engine cut off completely (you see rev counter spookily drop)- the car will completely coast or ‘sail’ as there is no impedance in the drive train at this stage....soon as you press the accelerator pedal the engine will cut back in....
I agree wafting is more interesting - but sailing is fun
Edit: IIRC I had to pull the right flappy paddle too?
 

th3h1ghlander

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CLS 350cdi (C218) 2012 / OM642
In hybrids....when on a motorway... the car will completely coast or ‘sail’ as there is no impedance in the drive train at this stage....soon as you press the accelerator pedal the engine will cut back in....
I agree wafting is more interesting - but sailing is fun
Edit: IIRC I had to pull the right flappy paddle too?

I wonder how much of that 68MPG figure was sailing ;)


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sonic

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E350CDI, SLC250d, FJR 1300
The last 150 mile run I did in my E350CDI came back at 51MPG, a mixture of motorway & A roads.
My FJF1300 does 55MPG, & thats a 1300cc 146BHP. Also I don't hang about on it either.
 
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Jasandjules

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C300 Estate (s205)
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Not been sailing as such though I do lift off sometimes and see it switches the electric motor on.... Does that also work in Sport Mode?
 
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Jasandjules

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But then we shouldn't have to resort to that kind of thing to get 50mpg when the book is 68........... I was just wondering if there is something wrong with my car, a sensor that needs changing etc... Saying that 50mpg is fine I am happy with that for the performance of the car but still I was expecting to get 60 mpg on a clear run........

ETA - my previous car had a book of 60 and I would often get 55 on a run.. With an average of about 48 even with a fair bit of town driving so it is not like I drive like a loony....
 

th3h1ghlander

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CLS 350cdi (C218) 2012 / OM642
But then we shouldn't have to resort to that kind of thing to get 50mpg when the book is 68........... I was just wondering if there is something wrong with my car, a sensor that needs changing etc... Saying that 50mpg is fine I am happy with that for the performance of the car but still I was expecting to get 60 mpg on a clear run........

ETA - my previous car had a book of 60 and I would often get 55 on a run.. With an average of about 48 even with a fair bit of town driving so it is not like I drive like a loony....

It does sound low, should be higher, but don't take one reading as lore. Check with multiple runs. Also, check your actual calculated MPG over a full tank of driving well, don't rely on the dash readout as your only source of truth.


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