Hi I am costas from London

[kalex]

Hi everyone I am the owner of 2014 ML 350 bluetech purchased used 6 months ago. Is the first time i buy a merc car having previously owned several bmw cars.

First impression of the car is that of upmarket feel and a comfortable ride as opposed to a sporty drive.

As a used premium car I expect things can/will go wrong and these are quite complicated vehicles. During the 6 months, i had to replace the upstream Nox sensor and an erratic rain sensor.

During this time i have only covered 3000 miles mostly city driving. I have observed that although it is a diesel , I get really poor mpq. So far i have averaged about 17.4 mpg over these 3000 miles.

My question to fellow owners of similar cars, what is the average mpg you get from your car? I have owned many diesel cars previously, including a 3.0 litre diesel X5 and was always getting above 28/30 mpg for similar driving .

Any views welcomed as i am interested to find out why i am only getting up to half the official mpg figures. thanks.

 

[00slk]

Hello and welcome.
I don't have an ML but I have owned a few diesels over my years and find the Mercedes range are not very economical and around town the diesels can be worse than a petrol car to run.

 

[sonic]

Welcome I have a 212 E350CDI always get over 48mpg between services. But I do very little town driving.

 

[kalex]

thanks for your quick response. 48mpg is very good.

Official urban mpg consumption for my car is stated as 34.5mpg but mine is half that and that includes driving very conservative - gentle acceleration and coasting as much as possible.

I an interested to find what is causing such a big discrepancy for me. thanks again.

 

[Blobcat]

Hello and welcome

 

[Dean Fletcher]

Hello and welcome

 

[John Laidlaw]

Welcome

 

[Terrykal]

Hello Costas,
The mpg values you are mentioning are from pump/wallet calculations or from the trip computer?
sometimes the trip may show different values from reality so the X5 you are mentioning might had been 22 instead of 28.
From my experience between BMW's and Mercs I would say that BMW's are more fuel efficient when comparing similar engines (bear in mind that in same segments for example D segment, a 3series is lighter than the equivalent C-Class of same age/era).

 

[SmartAmg]

Welcome, Costas.

 

[A.J.]

Hi Costas and welcome to the forum

 

[Srdl]

Hello Costas and welcome. That sounds very low to me even if you were doing a lot of stop start driving and just sitting in traffic queues. Are the tyre pressures correct and is the engine getting up to temperature properly (thermostat OK?). I’m not technical enough to make any useful suggestions but it might be worth getting it plugged into the Mercedes Star system first to see what fault codes are showing. If you let us know where you are, someone may be able to recommend a good Mercedes Independent garage who can do some diagnosis for you.

 

[kalex]

Hello everyone and thank you for your responses. I am based in West London, Ruislip area. I took the car to an independent specialist to replace a Nox sensor going bad and when asked him if such a low mpg was realistic for a diesel, he could not respond. No other faults were diagnosed at the time.

The car also had its B service week ago and everything was ok. I also use shell V power diesel as I was told it returns better mpg.

@Terrykal, for the ML both the onboard and a pump/wallet calculation are pretty close in their calculation. For the X5 was based on onboard computer.
I just filled diesel today, stats for the last fill were: 60ltr diesel, 239 miles driven, 18.1 mpg, 95% city driving.

By chance, I met someone yesterday with the same vehicle albeit the 250 bluetech version and he told me he was getting 40mpg in city driving and he thought his was bad. I know they are different engines but to me the cars should not have such big discrepancy.



I do really like the car very much but I am puzzled by this. Guess need to investigate further.....

 

[Srdl]

Hello everyone and thank you for your responses. I am based in West London, Ruislip area. I took the car to an independent specialist to replace a Nox sensor going bad and when asked him if such a low mpg was realistic for a diesel, he could not respond. No other faults were diagnosed at the time.

The car also had its B service week ago and everything was ok. I also use shell V power diesel as I was told it returns better mpg.

@Terrykal, for the ML both the onboard and a pump/wallet calculation are pretty close in their calculation. For the X5 was based on onboard computer.
I just filled diesel today, stats for the last fill were: 60ltr diesel, 239 miles driven, 18.1 mpg, 95% city driving.

By chance, I met someone yesterday with the same vehicle albeit the 250 bluetech version and he told me he was getting 40mpg in city driving and he thought his was bad. I know they are different engines but to me the cars should not have such big discrepancy.



I do really like the car very much but I am puzzled by this. Guess need to investigate further.....

For a start I would ditch the V Power diesel. Your car doesn’t need it. Perhaps a tankful every few months for the added detergents to clean things up but otherwise a waste of money in my opinion.

Did this “specialist” use the Mercedes Star system for diagnosis or just a general code reader. Often, for something more obscure like your problem, you need someone who had the right equipment and really understands their way round Mercedes engines.

I believe Wayne Gates at Harrow have a good reputation on this forum.

How long is your usual journey? If you are only doing four or five miles at a time then perhaps your figure isn’t surprising.

 

[Terrykal]

Sometimes it has to do with the driver's driving style too. I had for about 3 months a leased Volvo V40 d4 and was doing about 40mpg. A colleague of mine with same car bought from new and same mileage and year (17 plates) was doing 28mpg. But he never bothered with the car by checking tyre pressure etc.
Then he bought a used 66 plate discovery 2.0 diesel and was achieving 18mpg and he wasn't happy at all. Apparently the car needed service and also his driving style wasn't very thoughtful too.

Costas I had a cls500 V8 that was consuming almost same fuel amounts with my current e320 CDI, isn't this peculiar or not?
Sometimes an engine service or correct tyre pressure or even a good wheel alignment or better tyres can do some difference.
My 3series 320d Efficient dynamics could achieve 65mpg on M25 on my daily commute after the service and with the factory's light 16" on the car. After a distance of 8k miles mpg would drop to 60 mpg easily. And when I swapped my alloys with 18" and 255 at the back I was begging to see 58mpg after a service.

 

[kalex]

Terry and Steve thanks for your input. I guess many factors are at play and thus making determinations as to reasons of such poor mpg difficult.

Most of my trips so far have been locally within a 5/10 miles radius from home so they car does not get up to temperature.

Bought the car as I was planning couple European trips this year but due to covid there was a change of plans and now only used locally on short trips.

 

[Mercalba]

My ml 350(w164) is dramatically different between town and open roads. Sub 20mpg but nearer 40mpg on motorway. It’s a big lump of metal to get moving I guess.


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[Srdl]

Terry and Steve thanks for your input. I guess many factors are at play and thus making determinations as to reasons of such poor mpg difficult.

Most of my trips so far have been locally within a 5/10 miles radius from home so they car does not get up to temperature.

Bought the car as I was planning couple European trips this year but due to covid there was a change of plans and now only used locally on short trips.

It may well be right if you are only doing 5 to 10 miles at a time in city driving. The other problem you are going to have, with that sort of driving profile, is potential for your DPF (Diesel Particulate Filter) to get clogged up and the car go into limp mode. Your car could probably benefit from at least a 30 minute blast down the M4 but that may be difficult to justify as “essential” under the current restrictions.

 

[A.J.]

It may well be right if you are only doing 5 to 10 miles at a time in city driving. The other problem you are going to have, with that sort of driving profile, is potential for your DPF (Diesel Particulate Filter) to get clogged up and the car go into limp mode. Your car could probably benefit from at least a 30 minute blast down the M4 but that may be difficult to justify as “essential” under the current restrictions.

That is an interesting thought. I take mine for a run every now and again to try and keep the battery topped up. In the back of my mind is 'If I was stopped by a Policeman could that be an 'Essential journey' ?. My run usually takes me from Suffolk into Norfolk and back into Suffolk. My trip is from home to home and I don't get out f the car. A trip that doesn't exactly encourage the spread of Covid.

 

[SmartAmg]

That is an interesting thought. I take mine for a run every now and again to try and keep the battery topped up. In the back of my mind is 'If I was stopped by a Policeman could that be an 'Essential journey' ?. My run usually takes me from Suffolk into Norfolk and back into Suffolk. My trip is from home to home and I don't get out f the car. A trip that doesn't exactly encourage the spread of Covid.

Andy, I've not been out of St Helens for months, I use the car to and from work and groceries, but a couple of times a week I will go for a blast up and down the East Lancs Rd, and Rainford bypass, now strictly speaking that isn't essential travel, but I don't get out of the car, or meet anyone, so what harm is there in that, diesels in particular as we all know need a blast, I don't see the problem in that.

 

[Srdl]

That is an interesting thought. I take mine for a run every now and again to try and keep the battery topped up. In the back of my mind is 'If I was stopped by a Policeman could that be an 'Essential journey' ?. My run usually takes me from Suffolk into Norfolk and back into Suffolk. My trip is from home to home and I don't get out f the car. A trip that doesn't exactly encourage the spread of Covid.

Andy, I've not been out of St Helens for months, I use the car to and from work and groceries, but a couple of times a week I will go for a blast up and down the East Lancs Rd, and Rainford bypass, now strictly speaking that isn't essential travel, but I don't get out of the car, or meet anyone, so what harm is there in that, diesels in particular as we all know need a blast, I don't see the problem in that.

I totally agree and can’t see what harm there is if you don’t get out of your car other than the usual one about causing more work for the emergency services should you have an accident.

However, this is a quote from an Auto Express article:

Can I go for a drive?​

Although the argument can be made that you won’t catch Covid-19 or pass it on to anyone else if you’re alone inside your own car, simply going for a drive for pleasure would be classed as non-essential travel and would thus be prohibited by lockdown rules.

Can I drive my car during the Covid-19 lockdown? | Auto Express

England is in lockdown for the third time, with the rest of the UK employing similarly drastic measures - what does this mean for drivers?

www.autoexpress.co.uk