[Rh888]

2 bits of advice if I can please....?
1) My fuel consumption has dropped by 8mpg (according to obc). It's gone from 49.5 to 41.5mpg yet nothing has changed. Should I put it down to the cold weather?

2) My air filter is made up of the usual paper type material with a white fluffy covering also.
My mates car which is same model but a year older the air filter doesn't have the White fluff on the paper part of the element. It's possible the fluffy part has been removed.
What's the purpose of the fluff, will not having it affect anything??

Thanks.

 

[marco_polo]

1) Seems quite a bit, could be a combination of a cold engine, more load on the alternator, more driving in wet weather, etc. Could also be a poorly 'stat? Don't forget to double check your tyres pressures, they plummet in cold temps too.

2) The fluff is designed to increase the dust load capacity, catches the larger particles without effecting airflow. Not having the fluffy layer won't hurt at first, but will clog faster (lose performance quicker), or need replacing a bit more often.

 

[Wilko120d]

I got rid of my oe fluff covered air filter and stuck in a piper cross one and was amazed at the difference in performance

 

[0l0dom0l0]

2 bits of advice if I can please....?
1) My fuel consumption has dropped by 8mpg (according to obc). It's gone from 49.5 to 41.5mpg yet nothing has changed. Should I put it down to the cold weather?

Might be worth checking your thermostats. There's a thread in the how to section.

 

[Anish1993]

What driving style is that MPG you quoted for? City or Motorway

The weather would definitely take a toll on MPG keep that in mind.

I think it sounds about right tbh..

 

[Rh888]

My commute hasn't changed at all. The obc was stuck around 49mpg. Now it's down to 41 ish and all I can think is the cold weather. Checked my temp. It's 86 ish.
Anyone else have an idea???

 

[Míke]

Could it be down to winter diesel? Not sure if that would effect MPG.

 

[windyred]

mine has dropped from 49.5 to 45.5 since it had a service at BMW days before Christmas...
not sure its cold weather or crappy winter fuel ...
all tyres have been checked when cold and as its a new air filter it shouldn't be that...
so who knows ??

 

[BMWBrad]

Engines run richer in cold weather as the air is more dense therefore slightly more fuel is injected. This coupled with a slightly longer warm up phase will have a small impact on fuel efficiency. A plus side is that engines run much better in these circumstances

 

[rob180bhp]

Engines run richer in cold weather as the air is more dense therefore slightly more fuel is injected. This coupled with a slightly longer warm up phase will have a small impact on fuel efficiency. A plus side is that engines run much better in these circumstances

Splitting hairs a bit but the engine dosnt run richer in cold weather but will use more fuel due to the air being more dense but the afr reading will be the same

Sent from my SM-N910F using Tapatalk

 

[Rh888]

Afr reading???

 

[marco_polo]

Air:Fuel Ratio