2002 E46 318ti SE - MPG, how can I increase fuel efficiency on my car?

Hello all,


How can I increase my MPG on my 318ti SE 2002, it's just done 84k, full service history, last Oil serviced at Dealers, @ 77k last October 2010. recently had a crankcase breathing pipe replaced. I understand in 2009 Oct it had the Spec 2 of which includes, plugs with all the filters replaced.

Its seems to be getting worse for fuel efficiency.

I would like some advice on how I can increase the MPG? due to increase in fuel costs etc, its just isn't the same as it was when bought, Feb 2002, and its seems to be getting only around 360 miles (combined) on a £70 tank full, This seems incorrect - please can anyone help/advice on how to increase without spending a great deal to achieve this?

Can replacing the Fuel Filter help, i hear this may increase MPG?
other comments made have been:
Clean MAF sensor
Replace Spark Plugs
Air filter Clean - hoover air box
Fuel injectors clean (already using RedEx) is this any good for my car?
Change Lamda Sensor (can this be cleaned)

How can I make this car economical in the most cost efficient way?

Few questions again following some feedback everyone has posted:

Collapsed hoses - check engine for any worn or collapsed hoses which are common on the N42 engine - is this relating to the crankcase breather?

MAF - give the MAF and throttle body a clean as that will only improve the efficiency with which the engine runs – where is this located, and can a local garage clean this without taking half the engine out, can I do this myself?

Super unleaded - Give super unleaded a go if your not already using it, I found with my 316ti that I got an average 2-3MPG more using super unleaded – super unleaded, costs more, robbing peter to pay Paul springs to mind, just being honest, does it really give you more MPG, and is Redex any good at all?Average MPG/ never exceed 2k rpm - I can get 39/40 mpg out of my e36 318i if I drive carefully. My general rule is never exceeding 2k rpm around town and never exceed 70 on the motorway. oh and never press the throttle more than half way down – recently change gears at 2k rpm, changes noticed, average shows (mixed driving, some open roads, not many, half of 14 miles per day on open other traffic pain) 31.4 MPG, does this seem correct folks? Full tank - Why carry all that extra weight around and get less mpg – does weight on take make a huge difference? Please advice how to get more MPG, half then refill is what you are saying, is this right?

Remapping - Could always get it remapped as well, cost's about £250 an they can move the torque from the higher revs to the middle and increase fuel economy by 12 - 15%. Work that out with the cost of fuel today an how much you would save, probably pay for itself in a year, maybe less? – will this reduce performance? I like the BM power, since breather pipe has been replaced, its still noisy, however, last service carried out at 77, its now 84k, showing 6400 till next due, shall I wait or get it done now?


Engine breathing - both intake and internal crankcase ventilation are important, as is getting good combustion. So really anything that can cause a tail off in efficiency is worth checking out – how do I begin with this to be checked out, surely if the crankcase breather has been replaced, this will have been checked?

Wheels – are 16” standard SE – no plans to change these, although the thought for the future of having MV1s, as the 325 look had crossed my mind, however - driving changes and MPG implications, any comments at all?

PS – And why does the left side of the engine sound louder, will an oil change smoothen this out? Slight tap in engine recently occurring – can you help please?
Last October my chain tensioner broke for the chain, slipped etc. This was caused by me leaving the lights on, and some bright spark (with good intention) thinking it can be jumped/push started, I know the effects this has caused, anyhow, the engine always ran smooth, since this, and the repair (local Garage, good one too) its come back silent and tight, very good, however noticed, Less MPG, slight noise, like tapping from the right side of the engine top. I have has a leak of oil, breaher was causing this, this has now been replaced and so far so good. What would you advise of the slight tap in the top right of the engine, can an oil change/filter resolve this? Is there any further checking I can do my self/local garage (they assure me that part wasn’t even opened or repaired as it was not damaged by the incident of the chain slip) your comments would be greatly appreciated. I would like to keep this car mint as always and maintained well without extra unnecessary pounds as you all can appreciate given current climate.

Jay

Well without modding too much nothing! I have the 328i and it does like to drink its fuel! i usually go through about £30 - £40 a week and thats not driving very far but I heard on the radio some tips:

1. Change gear AT 2,000 rpm
2. Try to not use 1st gear unless absolutely necessary (I mean the high torque engines are fine pulling in 2nd)
3. Never use the AC it subtracts about 5mpg
4. Try to not race up to traffic lights, if you see red lights just let your foot off the accelerator, try not stopping!
5. Don't go fast around corners!
6. Lose any unnecessary weight, if your like me then your boot is usaually full, empty it if possiable!
7. This is the best one... Let your engine warm up for 5 minutes before any drive. A car will run at like 50% mpg when the engines cold! (or something like that)

Hope this helps, Petrol Prices are a B****RD

Consider trying the device shown on this page: POTN.COM

You may wish to get the silencer also.

I haven't tried this, but plan to do so.

"7. This is the best one... Let your engine warm up for 5 minutes before any drive" - Sorry for me is the worst one !!!! You waste fuel and 5 mins better drive straight away! Engine get faster temp. when you driving. It is good to quickly accelerate to desired speed and then keep the speed. Arriving at the roundabout or junction release is using the engine and gearbox. Good luck Remember check tyre pressure - to low pressure more petrol

Originally Posted by diddly666

Well without modding too much nothing! I have the 328i and it does like to drink its fuel! i usually go through about £30 - £40 a week and thats not driving very far but I heard on the radio some tips:

1. Change gear AT 2,000 rpm
2. Try to not use 1st gear unless absolutely necessary (I mean the high torque engines are fine pulling in 2nd)
3. Never use the AC it subtracts about 5mpg
4. Try to not race up to traffic lights, if you see red lights just let your foot off the accelerator, try not stopping!
5. Don't go fast around corners!
6. Lose any unnecessary weight, if your like me then your boot is usaually full, empty it if possiable!
7. This is the best one... Let your engine warm up for 5 minutes before any drive. A car will run at like 50% mpg when the engines cold! (or something like that)

Hope this helps, Petrol Prices are a B****RD

Is 3. true? Thats alot of MPG!

5. dont reduce your speed for the corner though, maintain it or you will have to accelarate again. Common sense that one though that everybody knows.

My auto gets 21mpg, and its almost impossible to increase the mpg figure without resetting it while on the motorway to get about 40 :p

i think rolling upto lights is a good one... try not to go down to 1st or 2nd, as they are the fuel guzzelers.

if in traffic, try and leave a gap between you and the car infront and slowly let your foot off the clutch untill it starts rolling along nicely.. no throttle needed just roll at 5mph (no throttle = more MPG) also when going down hill just roll down it, no throttle.

basicly walk and leave the car at home.. cant beat that

My wife's 318i 2001 is currently showing 31.7mpg, all town driving. So, i think that you are in the right ballpark.

Originally Posted by diddly666

3. Never use the AC it subtracts about 5mpg

Over @45mph, this is not true. Open windows create drag.

Get yourself a Passat TDI

Fit a tune-it box I'm getting 46.5mpg round the town in an 02 320td Compact and it's sorted out flat spots and increased bhp and torque consideribley...!
Check out my pic below and let me know your thoughts..
Happy motoring...!

http://m1088.photobucket.com/albumvi...edVA89tlYlD7Yp


Sent from my iPhone

Originally Posted by Jontyo

Fit a tune-it box

Had new MAF fitted. Seems to be losing MPG. Can anyone advise please? Thanks

Originally Posted by ao125

Over @45mph, this is not true. Open windows create drag.

True.. it will actually decrease ur gas milage if you have ur windows open... just use the ac. And I get 29mpg on my 330ci

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