[jinjur]

tbh, if i was getting 40s combined i would be over the moon......



Something tells me its not as powerful as it should really be either, obviously i cant quantify that but the quoted figure of 8.7 to 60 is WAYYYY off imo.

Not sure how anyone will diagnose this without an actual fault to go on.

JJ

[oscarguitar]

Sounds like something is not right. I have averaged 38.7 mph in a 335d for the last 20,000 miles. The only time it dropped below that was following a service, they seem to keep the engine running for ages not going anywhere which dorpped it down to 23 mph initially. If you can't get more than 40mph in a 320d, something is seriously out. Okay, I do mostly long trips and I don't rag it all the time but I like to use the grunt and handling when I can.

I changed from RFT to Non RFT (PS2) about 7000 miles ago and the milage didn't change at all. So I don't think the tyres are the cause. Also I thought cars were more efficient in cold weather due to the air being more dense and giving the cylinders a bigger charge, but the engine will take a little longer to warm up. Hope you get it sorted soon.

[lons]

My current computer mpg is 46.4 so def correct and has been around this and better since I bought the car mid Dec. Has done 3k (1k by me) and it was a demo car so salemen have probably run it before I got it. To tell the truth I was disappointed as the official stats say 59mpg combined. Haven't done a proper check so don't know how accurate this is. My mate with his 06 320d says he had a problem with his car last summer but it was well overdue a service and after that his mpg improved considerably and is def getting over 50. His motor has covered 73k now so maybe he has a "goodun" or drives like a granny (says he doesn't). Put it into a good independant garage where you know it's the mechanic who'll do the work and not an apprentice and use a decent grade of fuel, make sure tyre pressures are correct, then do a fill up check in case the computer's wrong.

[MOB]

I get more from that in my Cayman S

You car deffo has a problem if thats the real MPG

Originally Posted by CraigUK

Sorry to hijack the post slightly. Does the type of diesel you buy make that much difference? I have tried BP ultimate albeit only one tank and didn't really notice any difference from the supermarket fuel. To be honest at 15-20 pence more per litre there should me a big difference otherwise is it really justifiable?

I always use BP Ultimate in my diesel cars - noticeably smoother running and slightly better MPG, but it aint 15-20 pence per litre more, more like 5p or so?? If I have to use normal diesel the car feels less responsive to me

[J4MES]

I had mine into BMW Swindon (Dick Lovitt - a name which always makes me smile) - who concluded that there weren't any faults with mine (I have been getting 25 min, 37 max - do many other E91 163ps 320d owners, pre-eD, get much better?). Over how many miles did you get 23mpg? I'm off out now (in the cold) and I reckon I could get the same driving 'enthusiastically'... I'll let you know.

[J4MES]

I should add that while there may not be anything wrong with your (or my) car, it's still shockingly bad mpg. For a diesel. Even my Prodrive Impreza might have got just over 20mpg on a good day!

[CraigUK]

A quick question on diesel fuel consumption. As all BMW diesels are turbo charged they have next to no torque before about 1700rpm. Do people find they get better consumption by keeping the revs as low as possible or by staying in the torque band? Take my E91 320D Tourer for example, the auto gearbox when driven at a sedate pace is nearly always below the torque band when under about 65mph. If I pop it into sport mode then it sits in the torque band but I haven't experimented to see how it affects mpg. Here are a few engine maps off the superchips site so you can see what I'm waffling on about.

http://www.superchips.co.uk/curves/120d163bhp.pdf
http://www.superchips.co.uk/curves/B...bhp-Manual.pdf
http://www.superchips.co.uk/curves/335d286bhp.pdf

[oscarguitar]

The range says 593 miles to go after a fill up. Mind you I had been cruising dowm the motorway for the previous 200 miles. Usually get 500 miles out of a 55 litre fill.

[F104]

sub 30 mpg is ridiculous on a 320d. Can you see black smoke? You won't in daylight but at night with a car behind you it becomes very visible in your outside mirror when accelerating. First check is your air filter. See what's in the air box, and tap the filter element with the dirty (=darker) side down lightly on a flat surface. If loads of visible dust/sand comes out, then the filter replacement has been long overdue. Get a new airfilter asap.

[jinjur]

Hi F104,

No black smoke at all which surprised me, even if i gas it...........

I had a wee pull at the filter box the other night but couldnt get the filter out. All i could do was pull the side off and the air filter looks black, not sure if it was black when new though :S

Am i right in thinkign that the MAF sensor is what dictates what the MPG is on the OBC?

Could the shart MPG figure be down to a dicked MAF sensor?

I had read that they only had a 50K lifespan...


No?



JJ

[willhollin]

Not sure what filter goes on your engine, but a new one for mine looks like a white wooly sheep (minus head and legs), so you may have a problem there.

[jinjur]

Hmm.........white wooly sheep.................




COULD it be THAT easy?

Eh?

[willhollin]

Originally Posted by jinjur

Hmm.........white wooly sheep.................




COULD it be THAT easy?

Eh?

Looks very much like the one bottom left.

[jinjur]

Without being racist..............




Mine DOES NOT look like that in colour.

JJ

[willhollin]

Originally Posted by jinjur

Without being racist..............




Mine DOES NOT look like that in colour.

JJ

Best get it sorted mate.

You can pick them up pretty cheap, and there should be a DIY guide on here somewhere.

[F104]

Originally Posted by jinjur

Hi F104,

No black smoke at all which surprised me, even if i gas it...........

I had a wee pull at the filter box the other night but couldnt get the filter out. All i could do was pull the side off and the air filter looks black, not sure if it was black when new though :S

Am i right in thinkign that the MAF sensor is what dictates what the MPG is on the OBC?

Could the shart MPG figure be down to a dicked MAF sensor?

I had read that they only had a 50K lifespan...


No?



JJ

I'm no expert either. I would think a dicked MAF sensor results in black smoke too, at least with the amount of fuel you're burning. Do you have a DPF? As that would absorb visible smoke. If you don't know go on Bmw.info and find out. Only other one i can think off is a really stuck EGR valve, should be this on yours (also of bmw.info)? no? 15 or 16

[jinjur]

Hey bud, i actually pulled the EGR last week and gave it a good clean although it really didnt need it.

I checked that i could move the plunger and it was all ok.

I have been haing a slight hesitatino under light throttle on the motorway as well but i hadnt attributed that to the poor economy.

Still no errors showing btw.......had it checked again tonight

[Speedtrap]

Originally Posted by booforty

Look on the positive, I average about 17-18mpg

Should not be Paul - I average 21.6mpg

[jinjur]

Right.................air filter changed (HOLY FK that was hard work) and no difference in economy or shove

Was out in the father in laws Accord 2.2 CDti and was gutted to feel the punt it had and the way it went, 60 was dispatched so quickly.....it would TOTALLY destroy this 3.

I dont understand what can be wrong with this if its not showing anything on the error log in the computer....

Its not how im driving or the perception of how the BMW delivers its power....

This was based on as accurate as possible watch timings on acceleration to 60 and the BMW was about 10 seconds?

What is the point in having diagnostics if they dont spot somethign that bad?

JJ

[jinjur]

OK.............so say for example that i unplug the MAF or the EGR........i know they will throw a code but would the car be faster/more fuel efficient if either is not operating at 100%?

How does the car know the air flow?

Does it just run of a set of pre programmed figures on the ECU?




Regards
Andy

[paulcurtis]

Im following with interest here as my 320d seems a bit worse than i expect it to be.

If you reset the mpg and do some stop start around town driving then i can get it under 20. Mway driving i can get it up to 38ish. I can compare this to my old 120d where i have an average of around 43 and on a long drive could get that up to 50ish.

I feel that performance wise the 320 is slower than the 120 which i'd expect. It's heavier (touring) plus msport so more tire contact (bigger tyres) but not by much.

I have a longer drive next week but i expect this to be around 37 which is what it was on when i picked it up (55 plate, 60k miles).

If you reset the counter and take it on a motorway drive and do around 70 in 6th for a while, what do you get?

Im curious to see if you do find something out because it does seem to be less than i am expecting. The car is fully serviced and everything *seems* okay.

I will try a better grade of diesel and i am interested whether there are any remaps that would improve the power *and* the economy as they all claim to do...

cheers
paul

[F104]

Originally Posted by willhollin

Not sure what filter goes on your engine, but a new one for mine looks like a white wooly sheep (minus head and legs), so you may have a problem there.

Willhollin, I had the sheep bit on my E46 air filter. Al kind of pre filter wrapped around the paper filter. On the E92 320d it's not there anymore. The E46 filter was close to the windshield and a pain to get to. The E92 320d one is just behind the right front lights

Jinjur - can you copy & paste from bmw.info which parts you cleaned etc? This as on my E92 320d it's very difficult acces the EGR valve, or maybe we're not talking about the same thing. I wonder how you managed to clean the thing?