fuel comsumption

[sheebie]

hello,

i full tanked my 325 and it gave me about 230 miles per gallon, on a mix of mainly motorway but also some around town drive about 40miles around town the rest on motorways.

is this correct?

the only modification i have is a mild superchip? or is my car running rich?

[Ziggy]

hello,

i full tanked my 325 and it gave me about 230 miles per gallon, on a mix of mainly motorway but also some around town drive about 40miles around town the rest on motorways.

is this correct?

the only modification i have is a mild superchip? or is my car running rich?

Well there's obviously something wrong with that, so it's hard to answer your question without knowing what you meant to say...

If you meant 23 mpg, or indeed 230 on a tank then it should be doing better. Depends on how much fuel you used for a 'tank full' though - the best way to work it out is to start with a full tank, drive until it's nearly empty and then note how much it takes to fill it up.

How did you actually come up with your numbers, & what should they be?!

[Cloud]

i full tanked my 325 and it gave me about 230 miles per gallon, on a mix of mainly motorway but also some around town drive about 40miles around town the rest on motorways.

is this correct?

the only modification i have is a mild superchip? or is my car running rich?

I wouldn't quibble with 230mpg!
I assume you mean 23.
That's not bad. I used to get between 8 and 16 on my 320i

[Ziggy]

i full tanked my 325 and it gave me about 230 miles per gallon, on a mix of mainly motorway but also some around town drive about 40miles around town the rest on motorways.

is this correct?

the only modification i have is a mild superchip? or is my car running rich?

I wouldn't quibble with 230mpg!
I assume you mean 23.
That's not bad. I used to get between 8 and 16 on my 320i

Methinks there was something wrong with your 320i then, or you just didn't really aim for economy!

A 325 should do 30 if you're trying to drive relatively economically.

[sheebie]

sorry guys meant 230 per tank, it was full to the point when the pump clicked many times and no more fuel went in, any ideas where is should be looking to get better fuel economy? meaning what can possibly be wrong?

[Cloud]

Though I never found out for sure, a mechanic friend said the problem in mine was something to do with a sensor in the exhaust, one that can tell how rich the engine is running, and adjust the intake mix. Maybe it's that? Do these cars even have one of those sensors?

[stonesie]

I don't think his car will have a Lambda/O2 sensor.

The main sensor that fails is the BLUE coolant temperature sensor on the thermostat housing, this tells the ECU how hot the engine is and when it fails it usually tells the ECU that the engine is cold all the time. The ECU gives the engine a rich mix for warming up, so if the ecu thinks the engine is always cold it will give it too much fuel.

Theres a brown sensor next to it, thats for your temp gauge.


The BLUE sensor is about £20 from your local BMW dealer or a bit less from the genuine parts section on here

[Brianmoooore]

.The main sensor that fails is the BLUE coolant temperature sensor on the thermostat housing, this tells the ECU how hot the engine is and when it fails it usually tells the ECU that the engine is cold all the time.

The wiring from this sensor goes through the injector loom plug and socket under the inlet manifold. This plug and socket is notorious for collecting water, and rotting the wires off of the lower half.
Check this out before spending money on sensors.

[sheebie]

I don't think his car will have a Lambda/O2 sensor.

The main sensor that fails is the BLUE coolant temperature sensor on the thermostat housing, this tells the ECU how hot the engine is and when it fails it usually tells the ECU that the engine is cold all the time. The ECU gives the engine a rich mix for warming up, so if the ecu thinks the engine is always cold it will give it too much fuel.

Theres a brown sensor next to it, thats for your temp gauge.


The BLUE sensor is about £20 from your local BMW dealer or a bit less from the genuine parts section on here

funny you would say that after speaking to bm_boy he said to change that i got the sensor will change this first only £12 from ecp will let you know how it goes

[sheebie]

i replaced the blue sensor and all seems well now, thanks guys

[Morat]

Let us know how many miles you get from your next tank!

[Ziggy]

Let us know how many miles you get from your next tank!

And let us know how much it takes to fill up - unless you're planning on driving until you run out!

[Morat]

damn, good point

[sheebie]

Let us know how many miles you get from your next tank!

And let us know how much it takes to fill up - unless you're planning on driving until you run out!

i just filled up it cost £41.65 at 99.9p/litre!!! ( first time its like that in ages).

it will probably take 2 weeks to empty will let you guys know how much my next fill up is.

[marcp1987]

What size tank do you have? Has anyone run a 325 on a 55l tank?

[sheebie]

i have done 230miles on 45L of fuel, not bad mainly motorway driving, i think i must have a 55l tank, since it was showing practically empty when i filled up and i think you get about 6L ish when you hit reserve.

better then before anyways

also fuel my ends it like 94.9p let the good times roll

[Theo]

I think pre-facelift 325i's had a 55l tank from the factory.

230 miles on 10 gallons is ok, judging by how long it takes you to use your fuel you must do alot of short trips, which is always detrimental to good fuel economy.

[sheebie]

I think pre-facelift 325i's had a 55l tank from the factory.

230 miles on 10 gallons is ok, judging by how long it takes you to use your fuel you must do alot of short trips, which is always detrimental to good fuel economy.

its on a "g" plate,

i use it mainly to travel to uni 60mile round trip twice a week and lots of little journeys.

[hezicar]

Have had 400 miles on a long run at steady 80 mph on French Autoroute out of my 1989 325i cab with 2 up and luggage for 2 week holiday. Must have a 55 litre tank in it.

It was running on super unleaded as well.

[sheebie]

Have had 400 miles on a long run at steady 80 mph on French Autoroute out of my 1989 325i cab with 2 up and luggage for 2 week holiday. Must have a 55 litre tank in it.

It was running on super unleaded as well.

yeah 55L is what i thought, might try super unleaded since prices have come down, see what difference it makes and whether it is worth it.

[Theo]

It's easy to check how big the tank is, look at it from underneath and see if there is a small pipe connecting the two halves of the tank. If there is, it's 55l if there isn't it's 63l. Another way to check is to see if there is a hose going into the side of the fuel tank near the nearside rear wheel arch, only the bigger tanks have this.

A G-plate car should have the large tank.

[Brianmoooore]

might try super unleaded since prices have come down, see what difference it makes and whether it is worth it.

Will make absolutely, definitely no difference at all, except to your wallet!!
RON has nothing to do with power output or MPG.

[ChemicalAl]

Managed to get 360 miles from a full tank on my M10 316 (bought the car north of London and drove it all the way to Edinburgh in 6 hours on 1 tank (£45.00).
And someone said that M10's were hard on petrol - methinks not!
Compared with my 2001 328i its a dream!

[sheebie]

Managed to get 360 miles from a full tank on my M10 316 (bought the car north of London and drove it all the way to Edinburgh in 6 hours on 1 tank (£45.00).
And someone said that M10's were hard on petrol - methinks not!
Compared with my 2001 328i its a dream!

yeah a 4 pot should, mine gave me 150 to £12 when i drove it back from south wales at a steady speed 80-90mph.

i thought higher ron gave better economy and power?
whats the point of it then?

[Brianmoooore]

whats the point of it then?

None at all on any standard E30 engine. In fact the lowest RON available in the UK is considerably higher than is needed.
Fuels with a higher RON allow you to use higher compression ratios and spark advance without encountering detonation in the engine, and modern engines (M50Tu onwards), have knock sensors as part of the management system, which retard the ignition if detonation is detected.
If one of these engines is designed or modified to work with a higher RON fuel, and a lower RON is used, causing detonation, then the knock sensors will do their job, and lower power and reduced MPG will occur.
Even on these engines, using a higher RON than needed, will still not give any improvements.

[Theo]

yeah a 4 pot should, mine gave me 150 to £12 when i drove it back from south wales at a steady speed 80-90mph.

Interesting.

Assuming you bought the petrol at 105p/litre you achieved 59mpg, driving at between 80-90mph.

What car was this in?

[sheebie]

that was in my e30 325 petrol was under a pound dont remeber the exact figure, unless my fuel guage is fudged?

maybe thats why even thought it shows empty it only takes 45L to fill?

interesting need to do further tests

[patch]

Thought I'd join in
My 318i M10 does about 30mpg useing it to go to work(about 5 miles)so it never realy warms up, when I went to the Pod it returned 38.8 and that was with us stuck in an awfull traffic mess on the way home
I use this to calculate:
http://www.torquecars.com/tools/uk-mpg-calculator.php

[abelai]

On my 325i sport (3.91 diff) I get 28mpg average town and A road driving (I'm a highways inspector so lots of stop start during the day but cars always warm) As far as the fuel tanks concerned when the light comes on (needle well into reserve) I can do another 40miles till the obc shows 0 miles left, even then I can only fill up 58ish litres. I don't drive nice all the time but if I'm driving for work I normally get 32mpg weekends 25mpg

[Ilkorin]

my 316i M40 gets about 35mpg when I use it to go to work (again it's a 5-10 mile drive so the car only just warms up).....The best I've gotten is near enough 40 but now it's getting cold that's a bit of a dream........

[abelai]

my 316i M40 gets about 35mpg when I use it to go to work (again it's a 5-10 mile drive so the car only just warms up).....The best I've gotten is near enough 40 but now it's getting cold that's a bit of a dream........

Unless it's very cold then the outside temp really shouldn't effect it like that maybe you should check your thermostat and temp sender.

[ChemicalAl]

Now that i've go the weber carb fitted, the MPG should be even better!! Just passed a shell garage in Edinburgh this morning and the price for 95 RON Unleaded is now 93.5p!!!
Very good indeed!

[fuzzy]

93.5? ive not seen it that low yet diesel has got to be near £1 a litre mark ?

[sheebie]

93.5? ive not seen it that low yet diesel has got to be near £1 a litre mark ?

'

1.06p just of 21a on m25
petrol at 93.9p
and its a shell garage not asda or tesco!

[sati]

92.9P down my side , i always fill up at night on early morning (more fuel) my 318i gave me 22mpg wen booting it other wise its around 35-40mpg (heavy foot,lol)