[madman]

I used to get around 40mpg, very rarely below that, from a mixture of driving and the occasional blast.

This dropped to around 33mpg and has been in to the dealers twice now for problems with the fuel consumption.

Despite being told the fault has been rectified my MPG starts out good but slowly drops.

What I want to know is what are you 320i guys getting on average MPG wise?

I need to know if its worth getting this back in the dealers for a 3rd time.

[zltm089]

duno about 320 but...I collected my car on Weds. and dealer gave me a full tank...drove for like 4-5 hours on weds...mainly heavy acceleration/ high revs on M mode....

drove to work on thurs...about 3 hours drive ( took it easy because of weather and the oil warning light was on)

same goes for friday....3 hours drive...

tank is now near empty and fuel warning light is on....

went to fill it down the petrol station...£ 55 to fill up!!!...guess the tank wasn't completely empty!

[AlanIOW]

Hi

My 320i is cuurently averaging 29.7mpg which considering I drive like a nun[ish] is appalling, the highest I have ever had was 38mpg when touring round Wales last year after they replaced the Camshaft Sensor and Airflow Sensor and reprogrammed it. Mine is an Auto, but modern auto's are not supposed to be that much worse than a manual according to BMW's official figures.

Mine also has little or no low revs power, but really gets going above 3000rpm, I hope my new 320d arriving 1st March will be alot better both in fuel consumption and low down power. The engine management light came on 3 times yesterday, but I have given up with this car - Can't wait for the new one!!

[gr4z]

Is the drop in MPG related to the cold weather?

[bigfriendlyg]

U get 40mpg?

I dont get anywhere near that? If i drive smooth i can get it to 32mpg but on average it sits around 29mpg..... Im now concerned and will take it to a dealership c if they can advise..... But depends how much town drivin ive done and how much motor way drivin ive done...

Originally Posted by madman

I used to get around 40mpg, very rarely below that, from a mixture of driving and the occasional blast.

This dropped to around 33mpg and has been in to the dealers twice now for problems with the fuel consumption.

Despite being told the fault has been rectified my MPG starts out good but slowly drops.

What I want to know is what are you 320i guys getting on average MPG wise?

I need to know if its worth getting this back in the dealers for a 3rd time.

[madman]

Yeah 40 is about the average. It was about that last winter too so I know its not due to the weather.

It has had a 'clean cycle' at the dealers to remove sulfur buildup in the cat and went back in for something replacing, not sure was, something about nitrox?

Anyway, each time i got it back the mpg crept back up to around 40 but then slowly dropped back to around 33 and its doing it again.

I'm going to see how it goes over the next few fill ups and take it back in if it doesnt improve.

[boxtaboy]

Having similar issues with my wifes E91 320i Auto. Only gets 26-27 mpg in normal dricing and just over 30 mpg on a steady motorway run. Previously on her normal commute, she would easily get 33mpg in a Merc C180K auto. Been into the stealers 4 times and all they do is run diagnostics and come back with "computer says no". They have tried a couple of things such as resets and uploading latest software but no change. I cleaned the MAF today and had a drive around. It did seem to be more responsive low down as it was previously very sluggish but too early to say if it's helping the economy.

[yatesey]

Originally Posted by boxtaboy

I cleaned the MAF today .

wots a MAF....??

Im getting 30 ish at the mo!

[Budgie]

Originally Posted by yatesey

wots a MAF....??

Im getting 30 ish at the mo!

MASS AIRFLOW FILTER

[madman]

Originally Posted by Budgie

MASS AIRFLOW FILTER

Would be interesting to hear results of this.

Do you have a description of how you did it?

My car has nearly spent as much time in the stealers as it has with me so i'd rather look at something simple like that myself.

[CrimsonRedE93]

I was getting about 24-26mpg from my E93 320i auto, I took it in for checking and they said it was fine

[madman]

Originally Posted by CrimsonRedE93

I was getting about 24-26mpg from my E93 320i auto, I took it in for checking and they said it was fine

Thats Bull Sh*t. Dealers talking out of their arse.

I know the E93 is heavier than the E92 but MPG is very similar.

With ED an average MPG is 44 on paper and as experienced around 40mpg in real life, with a mixture of motorway/town driving.

I'm pissed off about getting sub 35mpg, If i was getting 25 i'd refuse to take the car back....that is unless of course you drive it like you stole it.

[CrimsonRedE93]

I must admit madman that the 320i auto SE E93 was a bad choice by me as I didn't test drive the same combination, it was too underpowered and when the 320i engine problems started to come up I got rid of it quickly and went 330d M E93, that's what I should have done the first time.

I does appear there is a big difference in fuel economy and the dealers don't know what to do, it's probably due to the fact that thier knowledge is limited and there are only a few people that can really understand what is really going on, modern technology has its advantages and disadvantages

[boxtaboy]

Originally Posted by madman

Would be interesting to hear results of this.

Do you have a description of how you did it?

My car has nearly spent as much time in the stealers as it has with me so i'd rather look at something simple like that myself.

Quite easy really, just needs a bit of patience and some tools (2 different torx bits, a socket, sorry, can't remember exact sizes) plus some electrical contact cleaner. I bought some stuff from halfords for £3.99. Most important that it's spray stuff that doesn't leave residue.



In the attached pic, you need to remove 3 torx screws, 2 from the front of the air inlet and one from the top inline with the BMW badge, then just ease this moulding off the main airbox unit, I think the pipe is roughly triangular in shape with no clips or brackets.

Next you have to remove the airbox by undoing the 2 bolts on top of the box and the jubliee clip that holds the outlet pipe in place. Be careful as there's a rubber bung on the bottom of the airbox (5 in the diagram) that can fall away into the engine compartment as you remove the airbox.

Once the box is free, carefully turn it over as the MAF cable is still attached. You'll see 5 or 6 torx screws which all need undoing to separate the two halves of the airbox. The two halves are a snug fit so they will need some gentle force to separate.

Once the box is open, you'll see the air filter. It should be cylindrical with the paper cone covered by a felt type cover. Mine was black but the paper part of the filter was clean. Pull off the filter and you should see a tube screwed to the housing with a section hanging down - this is the MAF sensor. You can either try and disconnect the MAF sensor cable or treat the sensor with the cable in place. I did this but placed some towels underneath the housing.

With the housing ready with towels underneath, I sprayed the MAF sensor (inside item 7 on the diagram) with the contact cleaner spray. I did this a few times from different angles then left it for a couple of mins so the excess dripped away and most of the spray evaporated. I then wiped the housing clean, but never touch the sensor with anything as it's very easily damaged.

Once cleaned up, it's a simple case of putting it all back together.

Drove it yesterday and I noticed some difference in pickup. It certainly didn't feel as sluggish and the auto box seemed to know what it was doing rather than snatching at gears. But the acid test was with my wife driving it today. Unprompted she commented on how much more responsive the car felt and also smoother picking up speed. She normally doesn't notice things like this so I'm taking it as more than my imagination. Still too early to comment on fuel economy but it's got a full tank of fuel and everything is reset. We'll just have to see how it goes.

As a note of caution, I have read that this can be a temporary fix. When a sensor is on it's way out, cleaning it get's it back to normal for a while but if it's knackered, it will pick up crap again and give out duff readings. New non duff sensors are probably less susceptible to picking up dirt etc.

I also wouldn't take any crap from the dealers. They profess to their kit being able to identify faulty MAF sensors but there are plenty of cases that this is simply not true. Changing the sensor for a new one has made problems go away all together.

[madman]

cheers for the info, much appreciated, but your pic doesnt work?

[boxtaboy]

Not sure what happened there. This should work

[E92 LeMans]

I used to get 30 MPg out of my 320i pre efficiant dynamics

[mgarvey]

Christ - getting sub-30 mpg figures in a 320i sounds pretty bad. My 325i auto gets 30mpg. Yes, its a lazier engine and doesn't need to be revved so hard to make progress, but its a 3.0 six so you'd expect it to be at least a bit worse.

[G82Dude]

With mainly stop/start traffic and the odd blast and dual carriageway, I get around 29 out of my 330i. Your 320i does sound bad!

[freon warrior]

Urban 29-30. I went to Cardiff yesterday, all motorway, 40.7.

[boxtaboy]

Just had an interesting development in my wife's 320i. Less than 2 weeks ago, the service indicator was showing a fair few '000 miles before a filter change was required. Since cleaning the MAF this has now plummeted to being due within 3,000 miles. Cleaning the MAF gave a definite improvement in driveability and slightly better fuel consumption.

I suppose what I'm concerned about is whether the MAF is was on it's way out or if me cleaning it has knackered it. Any thoughts ?