e39 525i mpg on motorway

visual · 23-08-2014 11:01am #1

Was cruising from dublin to cork on motorway just below 130kph or about 80mph and reset the mpg display. Drove 30 miles at constant speed to allow the read out to adjust it settled at 42.7 mpg and remained at that.

This surprised me as its a auto

my average duing the week is 30.7 mostly M50
+ short trips to shops.

I know the 6 pot is a good engine but that mpg is very good in my books. Maybe a little to good.
I know every will say do brim tank drive and brim again and do the maths. But I think the mpg read out (avarage mpg) is close enough

is this typical or am I fooling myself

corglass · 23-08-2014 11:13am

visual wrote: »

Was cruising from dublin to cork on motorway just below 130kph or about 80mph and reset the mpg display. Drove 30 miles at constant speed to allow the read out to adjust it settled at 42.7 mpg and remained at that.

This surprised me as its a auto

my average duing the week is 30.7 mostly M50
+ short trips to shops.

I know the 6 pot is a good engine but that mpg is very good in my books. Maybe a little to good.
I know every will say do brim tank drive and brim again and do the maths. But I think the mpg read out (avarage mpg) is close enough

is this typical or am I fooling myself

brim tank drive and brim again and do the maths

Casati · 23-08-2014 11:14am

Sounds like a tail-wind positively affected the economy. Also the fuel computer might not be accurate. I did a spin to Kerry in a 523i at that speed and averaged 33 mpg before and remembered thinking it was quite good for a 2.5

Driving with a tail wind can really help economy- I drove my laden Skoda Superb between Westport and Galway yesterday and averaged 3.9 litres per 100 km = 73 mpg. In real life I'd average 20 mpg less than that

Inbox · 23-08-2014 1:29pm

The auto cruises at lower revs afaik in the beemers.

visual · 23-08-2014 2:43pm

Revs was at 2500 at 130kph so its Bearley breaking a sweat cruising along
car 2 up with boot packed with luggage so think that would negate unnoticeable tail wind

Not suggesting that the car is ultra efficient in everyday use. But it does seem efficient on motorways

Voodoomelon · 23-08-2014 2:50pm

You have the M54, the M52 which was in my 728i was 300cc bigger and did about 35-36MPG at 120kph.

I'd well believe an E39 525 could get 40MPG+.

Sobanek · 23-08-2014 2:54pm

Voodoomelon wrote: »

You have the M54, the M52 which was in my 728i was 300cc bigger and did about 35-36MPG at 120kph.

I'd well believe an E39 525 could get 40MPG+.

34.5 MPG here, M54B22, automatic, air con on constantly, two people onboard, cruise control set at 120kph.
Faulty thermostat and MAF sensor :pac:

Voodoomelon · 23-08-2014 3:00pm

Your faulty thermostat alone would ruin your MPG.

Big Nasty · 23-08-2014 3:08pm

Factory figures are 35mpg motorway so I doubt you're getting 40+ @ 80mph.

I'm in a 520 (2.2) and get about 30mpg @ 80mph. Being a 2.5 it wouldn't have to work as hard so you could be getting 32/33mpg.

Interestingly when I had the 735 the motorway consumption was the same as the 520 (bigger engine and more weight but revving lower). Urban consump on the other hand......

bmwguy · 24-08-2014 11:17pm

I get 36 motorway at 120 kmph. 2004 e39 525 automatic. Happy enough with that. Checked it loads of times on the brim test, doesn't vary at all really. 25 in urban mixed driving conditions.

visual · 24-08-2014 11:20pm

Return trip same 42 mpg so can discount tail wind.

In my opinion the SE 525I (M54) auto easily returns over 40 mpg cruise control set at 80mph
steady driving on motorway.

Did drop below 36mpg on B roads and now I'm back in Dublin will be returning to my usual 30.7 mpg daily commute to work.

The advice I got when buying was the 525i was the better engine compaired to 523 more powerful and apparently better mpg when cruising at speed.

Gazzmonkey · 25-08-2014 11:48am

I wouldn't always trust the display OP, not until you can verify it by doing the maths.

My 2.0 TDI tells me that I'm getting 50mpg daily even as high as 61.4mpg on a few occasions, done the maths myself to check and it was closer to 45mpg!!!

My driving is about 70% motorway, 20% country road, 10% city.

Lex Luthor · 25-08-2014 12:16pm

I had a 523i E39 and best I could get was 33/34 mpg calculating by brimming tank and re-filling, etc. If you are getting this you are doing very very well. Mine was a manual aswell with no cruise control

SpannerMonkey · 25-08-2014 2:57pm

you cant believe the onboard mpg on E39's my one tells me im getting 45mpg on my e39 525d estate auto , in reality its more like 35-37mpg

do the maths or download a phone app that doies it for you . i use "FUELLOG" on android

Idbatterim · 25-08-2014 5:34pm

I could see how you could get that in that car at 100kmph, but at 130?!

visual · 25-08-2014 9:50pm

Idbatterim wrote: »

I could see how you could get that in that car at 100kmph, but at 130?!

Revs are at 2500 @ 130kph

Alanstrainor · 25-08-2014 9:55pm

The MPG readings on my e46 tend to be off, but not by a huge amount. That being said, I'm delighted with 25mpg out of my 325ci!!

visual · 02-09-2014 7:49pm

Alanstrainor wrote: »

The MPG readings on my e46 tend to be off, but not by a huge amount. That being said, I'm delighted with 25mpg out of my 325ci!!

That fine for avg mileage but what do you get when cruising on motorway

Alanstrainor · 02-09-2014 8:12pm

visual wrote: »

That fine for avg mileage but what do you get when cruising on motorway

Just looked up a photo I took of mine from a trip to Cork and it says 37.6...not too sure on the details of that one though, as in, how many miles that was over. I'm pretty certain that was me sitting at 110km/h most of the way and nursing it. Not terribly far off you to be honest...forgot I even had that picture.

obezyana · 02-09-2014 9:26pm

My car E46 323ci is doing 33mpg, mixed driving. If I don't have my lead shoes in she does well with the fuel

bigroad · 02-09-2014 10:25pm

My 528i used to do 36mpg motorway at 120kph.Back then bmw s were very good petol engines my 525tds would have a hard time to get 40mpg.

vectra · 03-09-2014 12:28pm

My sons now departed E46 320ci regularly gave him over 42mpg on dublin > Fermoy > Dublin

Now has an E60 20d and finds it hard to break 41mpg at same speed on same run.

sounds odd.

landmarkjohn · 03-09-2014 12:39pm

Yesterday tested my 730i on motorway between Shannon and Gort computer said I was getting 39 mpg at 84mph (shade under 140 kmph) over 30 miles or so, same on way back. Quite impressed.

OldMrBrennan83 · 03-09-2014 12:44pm

This post has been deleted.

e39 525i mpg on motorway

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