W204 C250 CDI MPG Concern

[MiltonRX]

Hi all,

I've recently bought the above car (facelift, estate) and while it is a great car I have some concerns about the fuel consumption as it's only averaging around 37mpg. It's an auto that's been driven fairly conservatively in E mode nearly the whole time and the miles I've done so far have been a 50/50 mixture of town and 50/70mph A roads. I know you can't trust the official figures but this does seem remarkably low and if there is a problem I'd like to get it sorted while I still have some recourse with the dealer.

Does anyone have any experience of real world MPG or what might cause it to be low?

Cheers

[Tinker2]

Seems lower than it should be when reading this

https://www.honestjohn.co.uk/realmpg/mercedes-benz...

[Sheepshanks]

It's lowish, but not remarkably low.

What distance is your typical journey? What did you drive before?

[MiltonRX]

Sheepshanks said:

It's lowish, but not remarkably low.

What distance is your typical journey? What did you drive before?

Anything between 5 and 20 miles, longest journey was about 30 miles of mostly A roads and a bit of stop/start traffic and managed about 41mpg there and back. ECO (stop/start) seems to randomly not be available/turn yellow as well sometimes. Will try and stretch its legs on a longer run next week and see if that improves things.

Drove a Toyota MR2 Roadster before and was hoping for an improvement in economy!

[MiltonRX]

Tinker2 said:

Seems lower than it should be when reading this

https://www.honestjohn.co.uk/realmpg/mercedes-benz...

Thanks for that, it's interesting that the C250 does seem to be the worst performer in relation to the reported figures.

[Sheepshanks]

MiltonRX said:

Anything between 5 and 20 miles, longest journey was about 30 miles of mostly A roads and a bit of stop/start traffic and managed about 41mpg there and back. ECO (stop/start) seems to randomly not be available/turn yellow as well sometimes. Will try and stretch its legs on a longer run next week and see if that improves things.

Drove a Toyota MR2 Roadster before and was hoping for an improvement in economy!

Shouldn't be such an issue at this time of year but diesels take a lot of warming up - well into the teens of miles in colder weather. My wife's Tiguan will show 90 on the water temp after 3 miles - but it also shows oil temp and it's still blank at that point!

Sorry if this is egg-sucking stuff, but you need to let the torque of the car waft it along. Any kind of "press-on" driving will murder the MPG, although there's a school of thought amongst MB diesel owners that it's good to get up to cruising speed reasonably quickly and then just sit there. Use lots of anticipation to minimise braking - on the over-run it's not using any fuel at all - and try and avoid actually stopping as getting moving again requires a lot more effort than if you can keep rolling.

ECO may not be working if the a/c is on and you've got it set low. But there's a bunch of other reasons too.

I have an older C270CDi and it needs a good steady run to get the MPG up. I'm 23 miles of rolling A road away from the motorway - it'll be approaching 40MPG when I get to the motorway and then over the next 100 miles or so of 75 MPH cruising it'll creep up into the low 50's.

[s70rmp]

That cant be right I'm in a C350 CDI and I'm getting a lot more MPG then that !

[fistenburger]

I've had two 250CDi s - E class & CLS. Granted, they're heavier cars, but they were both poor with economy on short journeys and commonly hovered around 33mpg with the distances you're mentioning. On longer motorway journeys over 50mpg was possible, but it took a good 20+ minutes for everything to warm through and get into the 40s.

[eldar]

I had a W205 C250CDI auto, the consumption averaged 42mpg over 50k miles. Varied between 28 and 63 depending on usage.

Don't trust the built in readout, mine over read by 15%, some under read, so you need to check real consumption.

[swagmeister]

My W204 C220 Cdi tells me over the last 1500 miles my av MPG sits at 53.4mpg

[nx172]

I had one of these for 2/3 years. It was remapped and driven with a moderately heavy foot. I'd only get 37MPG on the motorway with a light foot.

[MiltonRX]

Thanks for your input everyone, hopefully when it starts getting used for some longer journeys and we get used to driving an automatic diesel barge we'll see better figures.