320d poor MPG

[Pingman]

My '53 reg E46 320d (6 speed 150hp m47tu engined car) is only returning 43mpg on mixed driving, way down on official figures.

Fuel consumption (urban) 35.76 mpg
Fuel consumption (extra urban) 62.77 mpg
Fuel consumption (combined) 49.56 mpg

I'm far from flooring it either, been trying to get the best mpg I can for a while now so driving quite carefully with the throttle.

I travel about 40 miles a day with the majority dual carriageway, but have to drive out of town at either end of journey to get to dual carriageway and I do the very odd short run. So pretty mixed driving with a slight biased to dual carriageway.

Car has just ticked over 90,000 miles and has a DSH, is on 16" wheels with tyres correctly inflated and has had swirl flaps removed.

Any ideas?

[GarryA]

This is the factory spec for my 120d Coupe

Urban (mpg) 47.9
Extra-urban (mpg) 68.9
Combined (mpg) 60.1

49-53mpg is what it does in the real world.

[Chris_VRS]

43mpg sounds about right to be honest.

A few years ago when I used to sell cars I always gave customers the following insight into 'real world mpg'

Take the Urban figure & the Combined figure and the 'real world' figure will be half way between the two.

Given the official figures you've quoted, 43mpg sounds bang on.

[sinizter]

Sounds about right - obviously depends on your driving to be entirely sure.

All BMWs big MPG cars were 2007 or later.

[GarryA]

-15% off the combined

[to3m]

43mpg sounds reasonable. I had a 2001 320d (M47TU, 5 speed) for 4.5 years and I got 34mpg driving round town (stop-start, average around 20mph), and 45-49mpg on the motorway (depending on exact speed and emptiness of roads).

[Watcheswanted]

I agree 43mpg sounds correct. My wife had an 06 120d for about a year that averaged 38mpg combined then an 08 X3 2.0D that averaged 32 mpg combined. She does a 50/50 mix of town/motorway driving...

[helix402]

Check the air filter.

[motco]

If this is accompanied by a loss of power and increase in exhaust smoke, you may have a turbo boost loss due to split boost hose or ruptured intercooler.

[Panda76]

Sounds about right really.
My 2006 320d gets 34-36 in town.
Upto 54-55 on a motorway 70-80 mph
47 ish on mixed aiming for that.
You have to drive like a fairy mind to get 47 on mixed,otherwise it's more like 40-42.

[Patrick Bateman]

The only time I got close to the combined figure (I got 49mpg) was driving like a granny everywhere.

[anonymous-user]

Sounds about right - may be worth checking thermostat (s) are working to spec and that car is not running too cold in cooler weather. Not sure how you do this on a 3 but someone else will know...

[Pingman]

I thought people generally got ~50mpg on the 320d

drmark said:

Sounds about right - may be worth checking thermostat (s) are working to spec and that car is not running too cold in cooler weather. Not sure how you do this on a 3 but someone else will know...

Sounds like a good idea, any one know how?

[Blue Oval84]

Nah, people say that they get 50mpg. What they mean is that they get 50mpg on a motorway run.

If they were truthful they'd point out that in mixed use, with a fair few cold starts at this time of year they're really quite lucky if they even see 40mpg.

My Mondeo ST TDCi (a supposed 45-50mpg car according to many forums) only ever got about 33mpg on my average weekly cycle. Only ever saw above 40mpg if I was doing solely motorway work.

I'd be over the moon with 43mpg, no car I've ever owned, not even the diesels, have touched that figure!

[motco]

drmark said:

Sounds about right - may be worth checking thermostat (s) are working to spec and that car is not running too cold in cooler weather. Not sure how you do this on a 3 but someone else will know...

That will definitely cause a poor figure. My Mondeo diesel has a poorly functioning 'stat at the moment (the temperature is slow to rise, remains low, and cools rapidly when going down hills on the overrun) and the MPG is below 40 when it should be above under similar conditions.

[GarryA]

Pingman said:

I thought people generally got ~50mpg on the 320d

On the new 2.0d engines yes.

[roddo]

My wife has a 60 plate 320d it does 50mpg 50.4 to be exact. thats going to work in town traffic and short motorway runs

[Blue Oval84]

roddo said:

My wife has a 60 plate 320d it does 50mpg 50.4 to be exact. thats going to work in town traffic and short motorway runs

That's very impressive, what sort of distances is she covering every day on the short town runs?

[Pingman]

I want 50 mpg

[14-7]

My 123d averages around 41-43mpg per tank from a very mixed bag of driving.