W163 ML270 cdi fuel consumption mpg info

[MOZ]

Hi Guys,
Been away on holiday camping for a while, 1100 mile round trip to Cornwall and back ( from Harrogate, NYorks, 390 miles each way and 300 miles while down there pottering about for 2 weeks.

The question of fuel consumption on ml270's comes up a lot so I thought I would let anyone interested know how we got on.



Car had a full boot, pulling a small trailer and had a roof box ( just to kill my fuel consumption further) also air con was on and working. I got 32 mpg on the way down for the 390 mile trip pretty much obeying the 60 mph towing limit, and 29 mpg on the way back being a generally good but a little less paranoid ( difference must be due to it being down hill to Cornwall and up hill UK Yorkshire - nothing to do with slight mischief ) no real traffic jams on either journey - slight stop spoiler for 20 mins on the way down but not on the way back

We got 26mpg for the 300 miles pottering around ( boot unloaded, no trailer but still with the roof box) doing a good mix of 70 mph motorway mixed with town stop start and lots of slow winding hilly roads.

Which I didn't think was too bad given the loading and aerodynamic spoilers of a brick of a truck plus the additional brick on top .

We generally get mid to late teens mpg at home in general urban use, and it's very thirsty.

The figures quoted are genuine and calculated based on odometer reading and proper full tank to full tank top up fuel amounts and are not based on any trip computer data ( mine doesn't have a trip computer anyway)

I don't have any real data for normal unloaded, and non towing / roof box data for motorway driving as I haven't really had the chance to do it properly yet but will update when I finally get a chance to do it. ( a few attempts have suggested circa 35 mpg for 65 to 70 mph, but not proper full tank to full tank runs so slightly dubious data, so will have to confirm when I get a chance)

Hope this helps shed some real figures on how these beasts perform.
All the best.
Moz

 

[gIzzE]

I monitored mine and I got 28mpg over the 2 years and 40000 miles.

At first it was averaging around 24mpg, but after a decat, EGR bypass, swirlflaps removed, 235 wide EffecientGrip Tyres and a tuning box that crept up to a long term average of 28mpg.

On tanks purely doing sub 10 mile journeys though it was around 20mpg, about 350 miles to 80 litres of fuel.

Put a London run in there, 200 miles for me there and back, and you would see around 26mpg, 450 miles from a tank.

All motorway and we might hit 30mpg, which was 520 miles to the tank, but never saw anything like 32mpg which would be around 570 miles, and 35mpg would be impossible in that car imho, 620 miles just isn't going to happen I don't think.

Maybe someone has managed it?

 

[MOZ]

Your figures look pretty much like mine in general.
This latest data run was all motorway there and back (not the 26mpg in between) and was generally 60 to 65mph (due to trailer limit) so I guess this may explain the good 32mpg. my estimate of 35 mpg for normal motorway unloaded may be a tad optimistic as I wouldnt expect to be running at 60mph without the trailer I based it on a few runs over the past few months and the fact I got 32 with the extra weight and even worse aerodynamics.

Like anything, i guess it depends on lots of circumstances and how its driven, but thought i would post the info as a lot of people ask the question.

my summary would be very thirsty in general urban use mid teens to sub 20mpg, and somewhere near the 25mpg mark for normal mixture and 27 to 35 mpg for motorways (depending on driving style and speed - probably less for those with a heavy right foot )

 

[shorty]

My ML 270 is using 10 litres to every 100 km , about 28 mpg . My wife uses it for work commute a 30 mile round trip . Both CATs have been removed, the swirl flaps have been removed and there is a new MAF fitted, though it is running 275 tyres .I reckon its very reasonable given the size and weight of the car.

 

[MOZ]

Should have mentioned , mine are 275's too.

 

[colinp]

best I have had is 390 miles to the tank mixed motorway commute to work and less than 300 with the caravan on a motorway run swirl flap's removed and 255 tyres.
thinking of a full decat remap and egr delete see how that is.

 

[MOZ]

Colin, ouch, is yours a pre or post facelift model as I believe the tank capacity increased with the facelift (which mine is)

I'm not 100% sure but I think the pre facelift had a 73l tank and the post an 83l tank.

mine should have an 83 l tank I believe and on my two loner journeys both 390 miles i had aprox 1/3 of a tank left in (according to the fuel Guage) which is about right for the 55l it used, indicating around 580 miles for a full tank (based on the same consumption and emptying it fully).

if yours is a pre facelift with a smaller tank then the difference doesn't sound as bad as it may first appear.

Like I say, I never get anywhere near that normally as it is used around town and around winding, hilly, country roads (up ere in yorkshire probably get somewhere close to your 390 miles 21mpg with no motorways and general mixed driving - and much less in town only) so only on a very steady trailer limited long run.

Mine is totally standard with no EGR or swirl flap mods, both Cats are original, 275 tyres.

I have done a fair bit of work on it myself including new boost pipe to EGR, full service inc air filter etc., fuel filter and fuel line replace, new thermostat, new MAF, new air filter, new aux belt, checked and tightened all boost pipes etc, but no non standard mods, all mainly to try to improve fuel efficiency ( from my town running low levels).

 

[colinp]

its 2003 facelift tbh when the light comes on I fill it and its about 55l to the brim I never run it much after the light comes on so prob not as bad as I think lol.
the only thing to add after my 2 weeks holiday towing the caravan the back of the car above the exhaust was very black with soot indicating a bit of over fuel it does have an AMG tail pipe on it meaning the exhaust does not point down tho.
had it plugged in to the merc tool and there is no lights on apart from heater plug 3 being down all is well.

 

[West62]

Hi all, I've been following this forum for a couple of years since I bought my ml but this is my first post.
Particularly interesting thread for me as I'm obsessed with measuring my fuel consumption and never manage anything like the 30+ figures some people suggest!


The best I have managed is while towing my caravan (880kg) at 55-65mph is 29.8 mpg. This is on journeys around 250 miles, I've done loads of runs like this over 29 but never cracked the magic 30mpg.
The worst I've had is when I've had to do lots of short journeys around 2 miles, this got me down to 17.5mpg over a full tank.

Generally I get between 23-26 depending on how much town driving I have to do, its very rare that it strays far away from the 25mpg figure.

However things may now change as I had it remapped a fortnight ago, still waiting for the opportunity to fill it up n get a proper reading but it will be interesting to see as the car is running a lot smoother now.

 

[MOZ]

Hi west62,
Welcome to posting, I would be interested to see how you get on with the remap as it's something I've been considering too.
What did you remap for ( fuel economy or extra power or both?)
What sort of cost was it?

Getting 29+ towing a caravan sounds pretty good to me.
Thanks for posting and hopefully you can post a bit more and pass on some more ML advice/experiences.
All the best.
MoZ

 

[colinp]

as above will be good to see if the remap does improve it.
I have a Passat pd 130 mapped as my daily, improved drivability pulls like a train and if driven sensibly gives a few more mpg.

this is whats been done so far to the ML
de swirl flap
renew all the plastic diesel pipes
new thermostat
diff oils changed
transfer box oil changed
auto box serviced
changed tyre size

had it on holiday done over 1000 miles in two weeks towing the caravan and had no issues apart from it drinks diesel lol.
mot time now and it needs 2 front lower ball joints and outer arb bushes.
everything I have bought for it so far has been genuine Mercedes apart from the diff oil and its been reasonable ordered the 2 ball joints from merc yesterday £77.50 pair.

only problem I had was the drivers window regulator the 3 spot welds broke as I think the window was running off and had little lubrication re welded them and been ok since.
Colin

 

[West62]

The remap was for 'power' but in reality its just more efficient all round - more power when driving hard and less fuel consumption when driving gently. I've had the car 2 years and 20k miles (got it on 91k). Have done all the major service items except transmission fluid which I've not got round to yet.

Power went from 148.6 to 184.6
Torque went from 267.8lbft to 360.9 lbft

This has had a significant effect on the car as I'm sure you can imagine, I just wish I'd done it sooner! Could've gone slightly further with the power increase if I'd accepted a bit of black smoke but I wanted it to run cleanly.

Hopefully I'll get a long run in it within the next few weeks to test economy, the fuel needle definitely doesn't drop as fast as before but so far all I've done is a bit of light towing, straight away its better as the car never needs to drop into 4th to maintain speed up big hills, instead it just plods along in 5th never feeling strained.


Price -
The map was supposed to be £250 including dyno run before and after, but the place messed me around a bit and I had to take more time off work. I couldn't go elsewhere as this was the only local place I could find with a 4wd dyno without any height/weight restriction..
After some discussion I got the whole job for £180.

I'll post a picture of my dyno print out - with results before and after and also with just a generic map.... but could someone please tell me how to upload a photo!!

PS I'm on Conti m+s tyres, dyno run was done at 24degrees C ambient temp

 

[colinp]

that looks like good gains I will be doing this at some point along with a decat and egr delete, its not my daily so not in a hurry.
do you have the swirl flaps and cats on still?
Colin

 

[West62]

Yep still got full egr setup and cats in place, although have cleaned EGR, intercooler and hosework. Air filter was new recently.

Mot due in just under a month so I'll get that done in the next few days then take the cats out. Might be worth getting it back on the same dyno with cats out just to see if there's any increase in top end power with it breathing easier, would be interesting to know.

 

[West62]

Results of mpg after remap.

Very dissapointing for me as I was convinced this would get me extra economy when driven gently, but I have now done just over 1000 miles since the map (3 tanks - filling up around point fuel light comes on) and can say that it has had absolutely no affect at all on my fuel consumption.

On a long gentle motorway journey I got 28.2mpg, on the 'combined' style journey I've had 25.2mpg and 26.4mpg.

This is pretty much exactly what would've happened before, if anyone is thinking about getting a remap for economy its probably best to get a good mapper do a specific map for economy, not just assume that a normal remap will give enough increased efficiency to add mpg when driven gently..

 

[MOZ]

Thanks for that west62. You may not have got better fuel economy, but those gains you got were pretty impressive especially if you haven't lost on the fuel economy. Something I'm still seriously thinking about.

 

[kceire]

I do the one click fill test every tank fill and I average 25mpg.
That would be 99% city driving here in Dublin.