The ol' m30 - an economical motor!

[e34.535i.sport]

So as you probably know I've been 'restoring' the 535i for 18 months or so and now I'd like to say it's pretty much tip-top mechanically (just need these damn thrust arm bushes to get here)... Everything else seems spot on.

I took the car on a 550mile round trip and thought I'd check the 'reliability' of the OBC consumption readout and I was amazed with the results! I filled her right up before leaving...

I got down to bournemouth after 248 gruelling miles of motorway and a few twisty A-roads... (and an essential trip into town to the pizza hut). The OBC indicated 27.4mpg! I thought it was too good to be true so I went, filled up, and got the calculator out...

It took 41.12 litres to fill right back up which by my calculations is 9.04 gallons (2dp)... So 248 miles / 9.04 gallons = 27.43 MILES PER GALLON! Effectively this is spot on with the OBC only dealing in 1dp...

I reset consum1 on the way back taking a diferent route and got 28.8MPG ... The overall average for the trip being 28MPG... BARE IN MIND this is fully loaded with 4 passengers, luggage x4 and a full tank of petrol. Who says the m30 isn't economical?! :D (Pics to follow)

[E34-520iSE]

Yep, the OBC is amazingly accurate in it's calcs for fuel consumption & speed etc. When I set mine to show instant speed it gives the same figure as my sat-nav, which isn't bad considering
a) it's an OBC from a 535
b) I have a 535 dash cluster & coding plug
c) OBC's weren't standard kit in 2 litre cars.


Cheers,

Shaun M

[Ross]

I recently took a 350 mile trip(maiden voyage)in an M30 powered '89 E34 manual. I have no idea when he last time this car had been serviced and it had been idle for nearly a year according to the seller. Mostly interstate cruising at 85-90 mph, encountering fairly heavy traffic the last 70 miles. The OBC indicated 21.2 mpg.
I think they are capable mid twenties highway with more moderate speeds. Around town mid to high teens.

[Ferret]

I recently took a 350 mile trip(maiden voyage)in an M30 powered '89 E34 manual. I have no idea when he last time this car had been serviced and it had been idle for nearly a year according to the seller. Mostly interstate cruising at 85-90 mph, encountering fairly heavy traffic the last 70 miles. The OBC indicated 21.2 mpg.
I think they are capable mid twenties highway with more moderate speeds. Around town mid to high teens.

27(UK) is quite similar to what I get on a long trip. If I'm careful I can push it upto 30 if staying at 70 or under, and on one occasion I've got 35 out of it keeping it to 60 because I had time to spare.

For the main part, doing B road bashing and a 10 mile motorway thrash each day I tend to average about 18-22(UK)

[Derek A.]

Do you have a 2x4 zip tied to the back of your gas pedal?


So as you probably know I've been 'restoring' the 535i for 18 months or so and now I'd like to say it's pretty much tip-top mechanically (just need these damn thrust arm bushes to get here)... Everything else seems spot on.

I took the car on a 550mile round trip and thought I'd check the 'reliability' of the OBC consumption readout and I was amazed with the results! I filled her right up before leaving...

I got down to bournemouth after 248 gruelling miles of motorway and a few twisty A-roads... (and an essential trip into town to the pizza hut). The OBC indicated 27.4mpg! I thought it was too good to be true so I went, filled up, and got the calculator out...

It took 41.12 litres to fill right back up which by my calculations is 9.04 gallons (2dp)... So 248 miles / 9.04 gallons = 27.43 MILES PER GALLON! Effectively this is spot on with the OBC only dealing in 1dp...

I reset consum1 on the way back taking a diferent route and got 28.8MPG ... The overall average for the trip being 28MPG... BARE IN MIND this is fully loaded with 4 passengers, luggage x4 and a full tank of petrol. Who says the m30 isn't economical?! :D (Pics to follow)

[Jeff N.]

ha...wait till you swap in that lower rear end.

I'm lucky if I can coax 22 or 23 MPG out of my car if I cruise 65 to 70.

Of course...hehe...I am running a bit more displacement than you.

[e34.535i.sport]

Well I was amazed at the accuracy - especially after 18 yrs on the road and the correction factor being the factory 1000! I thought it was telling porkies when I saw 28.8mpg - The car must have weighed 2tonne with all the padssengers and luggage! Admittedly I was driving 'conservatively' pretty much the whole journey.

I'm worried about doing the rear end if it'll drop it to 23mpg highway!! Hopefully a 3.64 would leave me with 26mpg under the same conditions... Around town it's so ridiculous it wouldn't matter too much! Since taking out the EAT chip that wasn't suitable I've been getting around 17mpg... Saying that if I'm SUPER careful I can hit 22mpg in town if traffic is light!

Ferret - That's quite impressive! I've hit 30mpg once on a journey to wales but I was following a minibus limited to 63mph... It so wasn't worth the economy!

[anonymous1]

27(UK) is quite similar to what I get on a long trip. If I'm careful I can push it upto 30 if staying at 70 or under, and on one occasion I've got 35 out of it keeping it to 60 because I had time to spare.

For the main part, doing B road bashing and a 10 mile motorway thrash each day I tend to average about 18-22(UK)

I'm impressed, I only got 36.7 out of mine on the same trip as E34.Sport. Highest I've had is about 42mpg, but that was downhill at 40mph. :D

[winfred]

my all time high m30 mileage was in my old and sold 90 535ia 27.4 actual, the obc was never spot on and i never bothered trying to calibrate it, i can't remember if that trip was with the 3.91 or 4.27 diff, out of 5 or 6 trips in that car that one was the stand out mpg trip (trip = 2300 mile round trip from la to va over the same roads/gas stations) the normal high was around 24-25 which is what my shark got on it's only run to va so far, it's running the engine/injection and 5 speed right out of a 90 535 with 3.73 diff

[Ferret]

Around town it's so ridiculous it wouldn't matter too much! Since taking out the EAT chip that wasn't suitable I've been getting around 17mpg... Saying that if I'm SUPER careful I can hit 22mpg in town if traffic is light!

o.O Wow, even with me being lead-foot-larry in the 540i, I can still get an average of 19ish around town bombing it everywhere, 22 if I'm conservative with the throttle... interesting comparison between the 535i and 540i...!

[Paul in NZ]

i can get 27 only if i am very careful..nz is a hilly windy liitle country tho...and with the 3.64 I am running 2250 at 60 mph..i t would be better with a higher ratio

[e34.535i.sport]

i can get 27 only if i am very careful..nz is a hilly windy liitle country tho...and with the 3.64 I am running 2250 at 60 mph..i t would be better with a higher ratio

I run 2600 revs @ 70mph at the moment and 3000 revs @ 80 mph. If I change to a 3.64 I'd be looking at 2735 @ 70mph, and 3156 @ 80mph... I doubt this would effect highway economy too much...

[Adnan]

Hi,

The calculations shown appear to be for Imperial gallons. Using a 3.78 conversion to US gallons, the fuel consumption comes out to 22.8 miles/gallon.

Wasn't the 535 manual spec'd at 16 city, 26 highway? I never managed better than 22-23 with mine. The E90 328i I now drive is a pretty impressive one; I get around 31-32 mpg in freeway driving. My commute, which is 50% city streets still nets around 26-27 mpg.

I will say that the 535 never changed its fuel consumption in the 100k miles I put on her. Rock solid even with "obsolete" engine management.

Regards,
Adnan

[e34.535i.sport]

Hi,

The calculations shown appear to be for Imperial gallons. Using a 3.78 conversion to US gallons, the fuel consumption comes out to 22.8 miles/gallon.

Wasn't the 535 manual spec'd at 16 city, 26 highway? I never managed better than 22-23 with mine. The E90 328i I now drive is a pretty impressive one; I get around 31-32 mpg in freeway driving. My commute, which is 50% city streets still nets around 26-27 mpg.

I will say that the 535 never changed its fuel consumption in the 100k miles I put on her. Rock solid even with "obsolete" engine management.

Regards,
Adnan

Maybe I should have specified I used imperial gallons but that is what we use here in GB.

In regards to fuel consumption mine is spec'd at 29.1mpg* @ 90mph highway and 17.2mpg* around town... Taken from the original users manual. These are for the cars WITHOUT catalytic converters, with Cat is lower.

[BigKriss]

i would never call the m30 "economical", i get 14 mpg or 17L per 100kms for 100% city driving. I've changed over everything that people on here normally say to replace to increase fuel economy except the fuel injectors :(

my mothers e36 328i gets about 11-12L per 100kms, 100% city driving, short trips.

[Paul in NZ]

Maybe I should have specified I used imperial gallons but that is what we use here in GB.

In regards to fuel consumption mine is spec'd at 29.1mpg* @ 90mph highway and 17.2mpg* around town... Taken from the original users manual. These are for the cars WITHOUT catalytic converters, with Cat is lower.

i think you will find that its 29 mpg at 90 KM hr not 90 mph!

[Paul in NZ]

I run 2600 revs @ 70mph at the moment and 3000 revs @ 80 mph. If I change to a 3.64 I'd be looking at 2735 @ 70mph, and 3156 @ 80mph... I doubt this would effect highway economy too much...

i am gonna check to nite 70 mph is 112 km hr... i reckon you have already got a 3.64

[e34.535i.sport]

i think you will find that its 29 mpg at 90 KM hr not 90 mph!

No, I think you will find it's 29.1mpg at 90MPH...

http://img26.picoodle.com/data/img26/3/9/8/f_535IFUELCONm_142605c.jpg (http://www.picoodle.com/view.php?img=/3/9/8/f_535IFUELCONm_142605c.jpg&srv=img26)

[Paul in NZ]

No, I think you will find it's 29.1mpg at 90MPH...

http://img26.picoodle.com/data/img26/3/9/8/f_535IFUELCONm_142605c.jpg (http://www.picoodle.com/view.php?img=/3/9/8/f_535IFUELCONm_142605c.jpg&srv=img26)


wow...i was thinking of the top figure....35mpg

[e34.535i.sport]

wow...i was thinking of the top figure....35mpg

Although is Mr BMW telling porkies or is it me: 120km/h (90mph) - This can't be right can it? Shouldn't 120km/h = ~75mph... What you reckon?

[whiskychaser]

Although is Mr BMW telling porkies or is it me: 120km/h (90mph) - This can't be right can it? Shouldn't 120km/h = ~75mph... What you reckon?

Yes 120kph is 75mph. The figures suggest you get 29.1 at 90mph and (to one decimal place) 29.3 at 75mph. My owners manual only gives the 120kph figures:
535i 5 speed manual is 9.7l/100km ie 29.3 mpg
525i 5 speed manual is 8.5l/100km ie 33.4 mpg
525i 5 speed auto is 8.1l/100km ie 35.1 mpg

I think Mr BMW was laughing he when penned the last line

[Paul in NZ]

also interesting is the fact that most of the figures are for non cat models,whereby i thought non cat = non o2= open loop = not as efficient as it could be...

[e34.535i.sport]

I think Mr BMW was laughing he when penned the last line

You're not wrong! :D

[e34.535i.sport]

also interesting is the fact that most of the figures are for non cat models,whereby i thought non cat = non o2= open loop = not as efficient as it could be...

I don't think it is constantly in open loop because when I had my EAT chip in that threw a code for the o2 sensor which then messed it all up... It's spot on with the original chip and the fuel economy is much much higher since changing it back. I thought it gave better economy generally becasue a CAT is restrictive to the exhaust system but don't quote me on that one. :p

[Paul in NZ]

I run 2600 revs @ 70mph at the moment and 3000 revs @ 80 mph. If I change to a 3.64 I'd be looking at 2735 @ 70mph, and 3156 @ 80mph... I doubt this would effect highway economy too much...

as far as i could tell (the obc was reporting 112 km hr with constant resets) i was pulling 2750 at 112 km hr...thats with a 3.64 and prolly half worn 235 45 17 tyres plus or minus the needle width.....the speedo was nearly on 120 km hr

[e34.535i.sport]

as far as i could tell (the obc was reporting 112 km hr with constant resets) i was pulling 2750 at 112 km hr...thats with a 3.64 and prolly half worn 235 45 17 tyres plus or minus the needle width.....the speedo was nearly on 120 km hr

Hmmm that's intersting - That would be about right if I'm running a 3.46 as it's a 5.2% increase in revs... 2600 x 1.052 = 2735 revs @70mph.

What you reckon? Got under the other day but couldn't find the plate with the ratio on it...

Did you say you changed to a 3.64 or was it standard there?

[whiskychaser]

Hmmm that's intersting - That would be about right if I'm running a 3.46 as it's a 5.2% increase in revs... 2600 x 1.052 = 2735 revs @70mph.

What you reckon? Got under the other day but couldn't find the plate with the ratio on it...

Did you say you changed to a 3.64 or was it standard there?

In the interests of research - and because I had to go to Tesco - I did a little checking. Mine does 2000 rpm at 60mph and the OBC shows 40mpg. At 70mph it shows 35mpg. (At 2500rpm its doing 78mph.) I hasten to add thats if you hit the OBC once you have reached that speed and are cruising! On the way back I hit the traffic, made worse by the cops trying to sort a 4 car shunt. My OBC is now reading 20mpg:(.

[Paul in NZ]

Hmmm that's intersting - That would be about right if I'm running a 3.46 as it's a 5.2% increase in revs... 2600 x 1.052 = 2735 revs @70mph.

What you reckon? Got under the other day but couldn't find the plate with the ratio on it...

Did you say you changed to a 3.64 or was it standard there?

535IS
AFAIK standard,unless it was changed by a previuos owner.I am sure the "sport" has slightly lower gearing to add a wee bit more punch.

[e34.535i.sport]

In the interests of research - and because I had to go to Tesco - I did a little checking. Mine does 2000 rpm at 60mph and the OBC shows 40mpg. At 70mph it shows 35mpg. (At 2500rpm its doing 78mph.) I hasten to add thats if you hit the OBC once you have reached that speed and are cruising! On the way back I hit the traffic, made worse by the cops trying to sort a 4 car shunt. My OBC is now reading 20mpg:(.

I'm hitting almost 3k when doint 78mph which is intertesting! I thought the autos had a high (numerically!) rear - don't know on the front though how that affects it? Mine never cruises at 40mpg I can tell you that!!! The best I get cruising on a level road is 35mpg... but that is at around 60mph - 70mph I cruise at 30mpg! I think your's would beat mine hands down on a run!!! We'll have to see sometime :p

[whiskychaser]

I'm hitting almost 3k when doint 78mph which is intertesting! I thought the autos had a high (numerically!) rear - don't know on the front though how that affects it? Mine never cruises at 40mpg I can tell you that!!! The best I get cruising on a level road is 35mpg... but that is at around 60mph - 70mph I cruise at 30mpg! I think your's would beat mine hands down on a run!!! We'll have to see sometime :p

Read that much junk I cant remember where, but I'm pretty sure 5th is overdrive on this box so that may account for it. The downside as you know, is that unless you put it in sport mode, acceleration is 'leisurely':D

[whiskychaser]

I wouldnt report this unless I got better figures than John:D 240 miles to London. Apart from about 15 miles, most of it was motorway. OBC read 34 mpg and on refuel I made it 34.2. Near enough. That was a 4 hour drive with no delays. On the way back we crawled for an hour and barely got to cruise before the 'queue ahead' signs came on. To my amazement we still made 32.5mpg on the way back. I hate heights. But I made a mistake and ended up at the top of St Pauls. When my legs turn back from jelly I may post a pic:D

[e34.535i.sport]

I wouldnt report this unless I got better figures than John:D 240 miles to London. Apart from about 15 miles, most of it was motorway. OBC read 34 mpg and on refuel I made it 34.2. Near enough. That was a 4 hour drive with no delays. On the way back we crawled for an hour and barely got to cruise before the 'queue ahead' signs came on. To my amazement we still made 32.5mpg on the way back. I hate heights. But I made a mistake and ended up at the top of St Pauls. When my legs turn back from jelly I may post a pic:D


Thanks Colin! :D Good result on the return journey, it's horrible watching it go down and down when you're in traffic though isn't it!!!!

I'd be interested to see those pics too! :D