MPG's

[Widge]

Hi, no I'm not going to complain about the lousy mpg figures, that's the price I pay for sliding round roundabouts and overtaking mini coopers

I did 340 miles on a tank last week which was 50ltrs (not bad for a 325i), this works out as 30.91 MPG yet my OBC says 24.5!!!!! It's in an SE and was factory fitted so I havent got the wrong code plug. Any Ideas??

[hogweed]

I've never known any 325 to do more than 25mpg (and I've known a few...), although there are one or two punters on here who would disagree. Mine does 20-24 depending on how driven, and I believe it's well set up. I initially thought the OBC was measuring wrong too, but found it was me...

But if you're saying that you filled your tank, then drove 340 miles before filling up again, it's hard to see where you've gone wrong.

Are you sure it isn't a diesel?

Can I buy your engine please???

- Broke of Gloucester

[Simon13]

I am one of those people!, it's either my driving style, or i've got a really sweet 2.5 lump. Last tank on optimax 340miles , most of it driving in central london

[Widge]

IT IS NOT A DIESEL sorry did I shout that?

I brimmed the tank with the red light on which was 50 ltrs then drove from essex to yorkshire with the cruise control on 70mph and then drove around yorkshire till the light came on and filled it up again which was 50 ltrs or so. I suppose it's possible that my way of calculating the average will give a different reading to a constantly recalculating computer?
I must say I was driving very sedatley and normally round town the OBC says 15-19mpg ha ha
My brother has a 325i cab and did 388 miles on a tank when he drove down france so high mpgs are possible, would be a difficult record to beat!

You can have my engine if I can have a 2.7 it does have very very very noisy tappets though.

Did they ever make a diesel?????????? Havent seen any, or have they all died of shame.

[hogweed]

I'd really liek to get to the botom of this, because I've recently changed jobs and started commuting with the 325, and it's costing me six arms and legs.

I mean, even when new you couldn't get that sort of mpg out of them - I remember two mates getting a 325SE and a Sport back in 1989, and they both bemoaned the fact that they were getting low 20's with normal driving...

PS

then drove from essex to yorkshire with the cruise control on 70mph

What is "70 mph"? Is it something like 120mph, only slower?

[JoeP]

then drove from essex to yorkshire with the cruise control on 70mph

What is "70 mph"? Is it something like 120mph, only slower?

That's how he gets such good mileage, I generally get over 30 but then I'm a tight git and drive accordingly. My econometer's broken at the moment though so I'm dipping into the mid to low 20s.

[Zayyan]

Did they ever make a diesel?????????? Havent seen any, or have they all died of shame.

The made a 2.4 N/A diesel and a 2.4 turbo diesel (324d & 324td)

I quite fancy one but they don't actually appear to exist.

I don't know how you managed to get 31mpg

I've got just over 34mpg driving like a grandad (no offence to any grandads on here), with the very occasional irresistible raggage for a coupla miles (warm engine, cold, damp air, country road, 3am )....and it's a 316i

If you fancy swapping engines Widge, mine's very very tappety as well, so you won't get withdrawal symptoms

[Turbo-Brown]

Used to get 30mpg around town and just under 35 on the motorway in my '85 325i.

It returned better economy than my 205 1.9 GTi!

There's more to economical driving than just watching your speed though, that's probably only half the battle!

[Gwynleym10]

Hmm interesting reading, I'm getting pretty bad MPG on my m10 (1.8i) Seams to be around 26 or so, even on long journeys, I think it may well be my right foot... But surely it should be a bit better than 26

[Turbo-Brown]

Seems to me (based on purely circumstantial evidence) that some engines are better suited to some cars than others.

For example, if E30s came with 1.2 engines, you'd be ragging the nuts off it all the time just to get around so the economy would be awful!

The 2.5 engine on the other hand if you're in no hurry at all doesn't need to be stressed at all.

However, boggo cars stand a better chance of returning better fuel-mileage than sports as 4th and 5th gear on the lesser models are both higher gears so the engine's more relaxed when cruising.

[Widge]

I dunno all depends on how you drive and how you calculate the mpg.
I did the 340 miles including putting the zone chi in an ragging it a couple of times!!!

SO.... what bmw 6 speed gearbox will fit in an e30/ on to an m20 engine??
Because if I ever getaround to a 2.7 conversion I might as well change the box too whilst the engine is out, make motorways less expensive at 100mph (no officer my speedo is broken I would never intentionally break the speed limit).
Just fancy 6 gears too, also in the 6 speed models are the first 3/4 gears quite close to give really good acceleration?

[320Touring]

widge-when VW/Audi brought out the 6 speed boxes in their 1.9tdi's 6th actually had the same ratio as the old 5th!!!

The first 5 gears were just spaced differently to increase accel.

*everyone else*for a bit more info on driving more economically.. see this thread

http://www.e30zone.co.uk/modules.php?na ... highlight=

[Widge]

You would have thought the'd space 6 out a bit to make it more economical, althought it would only work with a quite torquey engine.
A guy I know has a saab aero which has a 7 speed auto, does 1500 rpm at 90 in 7th!!!!!!!

[320Touring]

yeah you would have thought that!

did several tests between my seat toledo TDI with a 5 cog box and my mates dad's Audi A4 TDI with a 6 speed box.

5th on mine at 70mph (indicated) was at 2500RPM, and on the Audi 6th was showing 2450RPM.

allowing for the extra drag of my car compared to the A4 i'd defo say that the final gears were exactly the same....

[Widge]

So does anyone know anything about 6 speed BM boxes?

[Chaos]

i saw just over 400 miles to a tank when i went to scotland to watch a rugby match a few yrs back in my old 88 325i SE.

I wasnt in any hurry and was paying for the petrol myself so i took it fairly easy - 75-80 odd.

[Adam318i]

In my 318i, out of a tenner i get about 85 miles, not sure if thats good or bad.

Adam

[Jhonno]

yeah you would have thought that!

did several tests between my seat toledo TDI with a 5 cog box and my mates dad's Audi A4 TDI with a 6 speed box.

5th on mine at 70mph (indicated) was at 2500RPM, and on the Audi 6th was showing 2450RPM.

allowing for the extra drag of my car compared to the A4 i'd defo say that the final gears were exactly the same....

er dude - drag has nothing to do with gear ratios

[Widge]

That's 32.1 MPG no bad!!!! Do you drive like my grannie?

I was gonna say the speed is finitly (sp?) determined by so many engine revs in such a gear with such a diff ratio and tyre size, drag will only affect the top speed, and acceleration.

[Adam318i]

Who me?

[JoeP]

So does anyone know anything about 6 speed BM boxes?

Try starting a new topic in the tech or modding section re 6 speed boxes instead of hijacking other threads, you might get more replies.

[Widge]

[quote="JoePTry starting a new topic in the tech or modding section re 6 speed boxes instead of hijacking other threads, you might get more replies.[/quote]

Ok was just and idle wonderence.

Yeah Adam do you drive like a gran or is it just 318's that more efficent than the 325i? What bhp does a 318 produce?

[Adam318i]

Hahah, lol, yea i guess i do drive like a granded.

Obviously a 318's gona be more effecient i'd guess. I think there either 105 or 115 bhp.

Im glad my MPG is high though, thought 80 miles out of a tenner was a bit poo.

Thanks for working it out

Adam

[Widge]

No worries mate just put the mony you save towards a 325i

[sabrje]

I just got 400 miles on 2 consectutive tanks of fuel. For the first tank I drove from London to Fishguard - then around Ireland a bit and I was taking it pretty easy due to a vibartion problem which I now now was a tyre witha bulge . The car was loaded with dog, mrs and all her clothes for a week away

The second tank was after filling up with cheaper petrol in Rosslare (only 67p/litre). I'd sorted the tyre by this point so came back along the M4 at 'slightly' over the national speed limit. The following day I went down to Bournemouth with a roof rack to get some 15 ft flooboards.

So, the car was loaded up and I still managed it - I think the secret is to keep a constant speed and not keep blipping the throttle....

[Simon13]

M40 1.8 is 115bhp
M42 1.8 136bhp
M10 1.8 i dont' know 105?

iS is most economical by a country mile

[Widge]

iS is most economical by a country mile

Does the OBC calculate MPG's by country miles??? If so this could explain my dicrepency. What is the differance between a statute mile and a rural mile???

[CaesarBob]

You lot really should give up this 6 pot nonsense if you can't afford the fuel.

I've had 40+mpg loads of times.

The key to economical driving is to avoid heavy acceleration and where possible maintain a constant speed. Stop start traffic really kills mpg.

[MONSPORT42]

Not to spoil those good figures,.. but doesn't the 323SE have a 60 or 65 litre tank, not a 50 litre? I regularly put over 55 litres in my Sport tank. Always fill to the brim and drive till empty and measure the mpg before I leave the garage. Averaging 28mpg. (2.7 auto)

[Chaos]

I did 340 miles on a tank last week which was 50ltrs (not bad for a 325i), this works out as 30.91 MPG yet my OBC says 24.5!!!!! It's in an SE and was factory fitted so I havent got the wrong code plug. Any Ideas??

havent got an OBC in the sport, but the one in my SE always read about 2 - 3mpg under what i was actually getting

[minime1275]

Widge, you might be interested in my discovery.

If your OBC is reading in "MPG", it is displaying American miles per gallon (America either has smaller gallons or longer miles than the UK!).

The correct display in the UK should be "M/G", which is Imperial miles per gallon.

You can change the display from US to Imperial (or European litres/100km! ) by pressing the small reset button in the bottom right-hand corner with a biro.

My average MPG went from 22.6 in US MPG to 28 Imperial M/G.

[Widge]

Don't mean to sound like a know it all but I knew that already. It reads 23.7 M/G or 19.4 MPG I always have it on M/G.
340 miles on 50 litres gives 30.9 M/G (IMP) OR 25.75 MPG (US gallons are smaller).
Do you think this discrepency could be because it is averaging the econometer rather than dividing distance travelled by fuel used??
Just an idea.
Cheers Minime do you have a 1275 mini by any chance??

[minime1275]

Don't mean to sound like a know it all but I knew that already. It reads 23.7 M/G or 19.4 MPG I always have it on M/G.
340 miles on 50 litres gives 30.9 M/G (IMP) OR 25.75 MPG (US gallons are smaller).
Do you think this discrepency could be because it is averaging the econometer rather than dividing distance travelled by fuel used??
Just an idea.
Cheers Minime do you have a 1275 mini by any chance??

Damn, and here's me feeling all smug too! Lol!

When my speedo stopped working (and subsequently my odometer/distance meter stopped recording mileage) the OBC said i was doin a max of between 0-5 M/G, so its based on distance travelled as displayed by the odometer. At the same time, the econometer was working fine, but did not affect the OBC M/G reading - not sure if thats what you mean.

Yes, I have a 1275 mini. Love it to bits but very time consuming to keep in working order. Currently running on 3 cylinders, so I thought feck it and bought my 320 off ebay last week for 300 quid.

[Andy_magic]

My 320i does on average 32mpg, I work this out by filling up when the light comes on, I press the trip reset button when this happens, I then put Ԛ£20 or whatever in and clock the miles till the light comes on again.

I convert the litres shown on the pump into gallons and then divide the miles by the gallons. (To get litres to gallons divide the litres by 4.54 and then divide the miles by the gallons)

This should change and be slightly better as I spent most of the day today sorting the engine management out and setting it up so it runs really well now and feels much cleaner.

Most of my driving is either just nipping round town or doing battle with reps and vectra muppeteers on the A12/A14 going up to Cambridge and back. I usually sit at about 80mph. My car has covered 175k miles

[Widge]

This should change and be slightly better as I spent most of the day today sorting the engine management out and setting it up so it runs really well now and feels much cleaner.

How on earth did you do that?????????
I just chipped mine!!! ha ha