[boutan]

Hey guys,

I've had my 125i for about a month. I've only done 1500km. But I am only getting about 350km out of a full tank. I'm using 95 fuel, no ethanol.

I'm not driving it particularly aggressively, mostly in comfort mode.

I am only doing short distances each trip (5-10km) but that is the same for my other cars and I not have this problem.

Any others experienced anything like this?

[westphone]

No, that sounds strange, I have some number for you. I used 98, which supposedly give you 5% extra. M135i MT

Cruise control most of my way on highway, long trip, nearly no stop, almost break 600 km/h. Comfort Mode.

Regular driving to work, stop and go + some 40~50 km/h crawling, about 9~10 km per liter. Comfort + ECO PRO. Each trip is 6 km almost exactly.

Mountain road driving aggressively last weekend, raining, sports + & DSC off. Understeer into corner and exiting corner spinning wheel all that stuff, came home computer display about 7 km/h per liter (I thought it should be much less, guess I wasn't pushing as hard going downhill.) Our fuel tank when empty let's just say it's 50 liter, that'd still give you about 350 km/h. Take off another 10% for argument sake there is still 320 km-ish per tank.

I am sure you have refreshed your trip computer for sure, not it hurts to check. If that's indeed what you're getting, I'd head back to the factory.

Regards,

[westphone]

I some pictures for your reference....

The top picture is me driving that long trips, but some consider this cheating for fuel mileage because I am on the highway cruise control most of the time.

The bottom two is the same 118i doing mostly work commune, you can see the average speed. We don't have 125i in Taiwan, but I hope this serve as some reference for you.

[SteveC]

Hi there,

The problem is likely to be the short trips. In order to have the engine run smoothly while still cold the ECU increases the fuel:air ratio for a richer mix, much like the chokes of old, which restricted the air and increased fuel.

In addition, I imagine there's more stop and go than a longer trip, which again requires the ECU to provide extra fuel for acceleration vs. a steady state cruise.

Short trips really are a recipe for poor fuel consumption, I assume you're adding around 50l per fill up which means 14L per 100km, 7km per litre or 20mpg.....That is pretty poor, even considering the short trips

I think if that was my car, I'd be taking it for a proper drive on a longer trip on a mix or roads to see what the overall consumption looks like....you should be getting 50% better, ie. 9.3L, 10.5, 30 respectively

[tkburn]

I have a f20 125i manual and manage between 500km and 550km on a tank of 95 octane mostly city driving ave 8-9l/100km , this is however driving for another 100km after the fuel reserve message appears (at about 400km 1/4 tank remaining) , it sounds as though you may be refilling with still a quarter tank available.

[frashed]

Mate, there's some serious differences in fuel economy...

Just to clarify... is that your estimate based on fuel consumed/distance traveled vs estimated distance remaining?

I'm sitting on 10l/100km and that is with very conservative driving... no idea how anyone is hitting 8l or 9l?

[peanut125i]

i have averaged 8.8l/100km over 13500km. cant remember what i did when i just got it though.

[rhoolwerf]

My bmw 116iA seems to have a sweet spot around 100km/h. That's about 6l/100km. Going towards 130km/h goes over 8,5l/100km..

Lots of short rides are horrible for fuel consumption either.

[ovekvam]

Originally Posted by rhoolwerf

My bmw 116iA seems to have a sweet spot around 100km/h. That's about 6l/100km. Going towards 130km/h goes over 8,5l/100km...

Our manual 116i is less thirsty around 50-60 km/h. My consumption record for a trip is 5L/100km. 100 km/h is too fast if you want to save fuel.

[rhoolwerf]

Originally Posted by ovekvam

Our manual 116i is less thirsty around 50-60 km/h. My consumption record for a trip is 5L/100km. 100 km/h is too fast if you want to save fuel.

Yea but 50km/h isn't realistic on a daily commute of 160km
Then again I don't really think about saving fuel as my company pays for it, but frashed mentioned he didn't know how people get their average below 8l/100km.

[Dim73]

Here are the stats from my recent trip. I think that an average consumption of 8.1 l/100 km for a distance of nearly 1600 km is acceptable for an 116i with auto transmission, since this trip included almost everything:

- Driving long distances in national road/highways with an average speed of 150 km/h
- Mountain ascend/descend with continuous bends and many U-turns
- Driving in county roads with an average speed of 80 km/h

The overall mileage of our car is ~4500 km.

Note: ECO PRO mode is completely useless even on open road. Maybe there should be some kind of firmware upgrade to modify the accelerator pedal threshold or whatever.

[js39]

Australia, 125i AT.

I have averaged 8.5l/100km over 5500km.

To OP -

350km out of a full tank..? Please try 98RON first, and do another.. say 1000km. For some cars I believe it'll take times for engine to run in, mine could only have done like around 4xx km at the beginning, now I can easily get up to at least 550 km before the 'add fuel icon' appears, and probably 600 km out of a full tank no problem.

p.s, 60% highway driving (average 100km/hr only), 40% urban.

[boutan]

Thanks for the feedback guys. I have it in at the dealer as we speak and they are looking at it for me. They thought 300-350km was very unusual. My first 3 full tanks only did 1000km... Will post the results here when I get it back.

[ttimbo]

Seems odd...I'm getting much better than that from my M135i!

[matthewproctor]

I've got about 400km per tank with my new 125i Auto. Although I am 'filling up' when there's still around 40km on the suggested trip meter, and each fill up is around 45L.

Is the tank 50L? Also the book says fill up and finish with auto stop, and that it can 'damage the engine if overfilled'. Do you guys adhere to this too?

Perhaps i'm not filling up enough?

[ant234]

FYI when new my 125i manual was doing 9s/100km... now around 5000km in, it has averaged out to 8.1l/100km

I drive relatively conservative and stuck in traffic most of the time. I usually drive 30 km at a time into and out of the city.

[boutan]

Well, they gave it a look over and everything seems to be fine.

I can only guess that driving the engine cold so much is chewing extra fuel. I'm going to keep an eye on it as I push towards 5000kms and see how it improves (if it improves).

[frashed]

I'm on 12,000km and sitting on 9.9l after 3000km travelled since reset.

[AusF20/F48]

I was told by my dealer's technicians that two things are in play, firstly the engine is tight and secondly, for the first 1000km the car's master and engine's management systems assess all the conditions of components, Engine, gearbox and all sensors and this has some effect the fuel consumption.
The good news is that the car does get better fuel economy as the kms increase. Mine has around 6000kms now.

I was only getting around the 400km per tank originally, and now get around the 500km even with some spirited driving in Sport (paddles) city and some Motor way.

[cozza]

Originally Posted by AusF20

I was only getting around the 400km per tank originally, and now get around the 500km even with some spirited driving in Sport (paddles) city and some Motor way.

Good to know. I too was struggling to comprehend why consumption wasn't what was promised, although I've barely done 1,500 kms yet.

[Cateye]

With M135. I get abt 400/450km (balance 1/4 fuel) per tank if I drive causally. However if I drive hard, I get 300km, balance 1/4 of petrol. ..

[Teg]

Hi

On the first proper journey I did in my new 120d, I got 57 mpg. The claimed combined from BMW is 64 mpg. The 1 hour journey was a mixture of 30 mph zones, dual carriageway and then stop start urban driving (but with stop/start function off).

I thought that was pretty good for a brand new car.

Second journey was a 3hr motorway trip at much faster speeds. Still managed to get 50 mpg out of it though.

(Sorry that all the measurements are different to the other posts, but the difference in read out and claimed should, hopefully, be useful.)