XSeries-forum

I like my M50D more and more, and find it a very complete car that does everything well and just a "feel good" kind of car.

However, one surprise is the fuel consumption, which at 12 litres/100 km (= 23.5 mpg) over the last 2000 km is quite poor, and so far off the claimed 41 mpg that it is not even funny.

It has been a mixture of 70 % fast(ish) motorway duties (cruising 150 - 160 kph) and city driving. It equates to a range of about 700 km.

It is not far off what my F10 M5 was doing on the same kind of driving, which is a bit of joke considering that's performance.

Airfilter changed 5000 km ago, on 20" runflat tyres. I accept that a heavy SUV with 381 bhp will never be that economical but still was expecting 26-29 mpg on a run.

Anyone experiencing the same, or do I have a problem?

Yours does sound low?
Had mine for about a year now and my average over 13k miles is just over 30mpg.
On my daily 25 mile work commute across A and B roads (average 27 mph) I'm getting between 30 and 33 mpg on the 21" summer run flats and up to 35mpg on the 20" winter non Run flats.
So a vast difference.
Drove to the Swiss Alps in February (750miles each way) fully loaded and was getting 30mpg on average 60-70mph.

I suppose it depends on what kind of driving you are doing ... and how you drive it.

Most of my driving is quite sedate, but I do lots of short journeys crawling or sitting still in traffic. When on the motorway and the roads do open up I dont like to hang about and the aerodynamics of a brick on wheels have a huge effect once you get past a certain speed. You mention cruising at 90-100 mph and at that speed the mpg nosedives.

So in short, 23.5 sounds normal to me.

I'm averaging just over 30mpg too. That's with mostly longer runs, not much town/city driving.

Thanks. Will have a 450 km motorway journey Thursday, will see what that does, but probably right that the weight, 4 WD, 20" steamrollers and aerodynamics and elevated cruising speed all conspire to low MPG. Just a bit of an eye opener that it is that far from the claimed figures, and that close to those of a 560 bhp M5.

Real world figures are typically 25-30% below test data which is why the new WLTP test cycle is coming in now.

Try pegging it back to 110-120 kph, makes a huge difference with my M, which also has the aerodynamics of a small house.

I’m at an average of 29mpg after 3000 miles. That’s the car reading so probably a bit generous.

In an other M 50d post where someone was asking if he should buy a 12 month old X5 50d with 1K miles on it for £25 K less than it was new, £25 per mile depreciation

[quote="Horizon"]
In an other M 50d post where someone was asking if he should buy a 12 month old X5 50d with 1K miles on it for £25 K less than it was new, £25 per mile depreciation

I’ve driven the m50d I’m considering buying a few times and mpg seems poor for a Diesel - Even tho it’s fast for such a big car. Power also seems very on / off

[quote="Horizon"]
In an other M 50d post where someone was asking if he should buy a 12 month old X5 50d with 1K miles on it for £25 K less than it was new, £25 per mile depreciation

Its such a great fun car to drive and for its size the power is just great.
It does everything you want it to do and carries 5-7 people with a full load with ease.
I have no regrets in buying it and would recommend to anyone.
Spending so much money on one, there should be no reason to be concerned with the mpg.

I found this on the net:
http://bioage.typepad.com/.shared/image ... obild1.png

and whilst none of the cars are quite as brick shaped as the X5, the message is pretty clear - your fuel economy will improve by at least 33% if you slow down from 100 mph to 80 mph. That would put your 23.5 mpg up to 31.3.

If you really want to watch the needle head south in real time try putting a couple of bikes on the roof. I did that for a 450 mile journey once and it nearly made me cry!

I'm not suggesting you change your driving habits at all, just suggesting that there's probably nothing wrong with your car mechanically. Enjoy!

[quote="Horizon"]
In an other M 50d post where someone was asking if he should buy a 12 month old X5 50d with 1K miles on it for £25 K less than it was new, £25 per mile depreciation