[TwistedX]

Originally Posted by ScottSinger

Are u describing the air flow led’s on the seat icon ?
That’s the way it should work.

Yes but why does the passenger side only have 2 versus the driverside has 3?

[jdgamble]

I did an 90/10 commute the other day and ended like 30 indicated (probably lower in real life). 16 is too low. It's CPO, and still under factory warranty. You have a very strong case that there is something wrong. Let the dealer figure it out.

[aerobod]

Originally Posted by TwistedX

Yes but why does the passenger side only have 2 versus the driverside has 3?

The passenger doesn’t have selection of distribution to the windshield, it is a driver only function (this is in the manual). It makes sense that that is the case, as the driver gets to decide how fogged up the windows should be.

[itzzoscar]

I get about 11-14 80/20 city/highway driving but I have a heavy foot and bm3 stage 2 flash

[TwistedX]

I turned the sport to chassis and drivetrain and the live MPG under the tach showed better MPG. I think that I will reset the dash and idrive on the first and run one month in comfort only and then another in sport only and see what happens. I will see if the dealer can look at the alignment first as to reduce the number of variables.

Thank you Aerobud for explaining the HVAC to me, makes sense.

[aerobod]

Fuel consumption figures displayed in the on board computer are typically only derived from fuel flow metered at the injectors and are really only guidelines that aren’t that accurate. The easiest way to measure consumption somewhat accurately is to fill to the first click from a given fuel pump at your favourite fuel station, use most of the tank of fuel and then fill up at the same pump again. You should be within about 1% of fuel volume measured.

Distance travelled is another factor. The standard 245/35-18 rear tyres on my M240i over register speed by 4%, but register distance within 1% accuracy. The 225/45-18 winter tyres I use under register speed by 1% and also under register distance by 4% - all as verified by GPS and distance measurement between two accurately known points. In summary, don’t assume odometer distance is very accurate especially if you aren’t running stock rear tyre sizes.

I just keep a record of fuel fills divided by accurate distance measurements to understand my fuel usage.

[Maynard]

Ditto what Scott said - that threw me too, but if you look in your manual I bet that there are only supposed to be 2 bars for passenger side (mine is a '16 228, but I doubt it is that model-specific). I think the driver's 3rd bar is either the center outlet, or the base of windshield.

Related to this is the 'secret of the wheel' - i.e. that 90% of your effective temp control will come from that little 70's era blue-red wheel, rather than the NASA supercomputer sensor-driven environmental control unit.

[baege]

just finishing off my first tank of fuel with my 18 m240i xdrive and with 90% city driving in sport mode with generous application of throttle and use of paddles...but never full throttle and never over 4500 rpm...i am at 15 mpg...

[Ron Jeffries]

On my M240i, driven 60% in Sport, and thus at least one gear lower than it needs to be, and with essentially no highway miles, mostly 45-55 limit semi-rural roads, driven dare i say “briskly”: 21.3 mpg, 11 liters/100km

[cxp213]

Originally Posted by ScottSinger

I expect to be kicked off this forum for linking to a Scotty Kilmer video but choosing or even needing a fuel cleaner on direct injection is not easy or shown to help. High quality fuel is the key and additives can bind with water or alcohol in the tank and in certain situations take a toll on fuel pump.

[url]https://m.youtube.com/watch?v=gg9ppeUMpK4[url]

I don't think I've read that before but interesting...
Not a fan of Scotty and just find him to be annoying. Have you seen this video?

Originally Posted by TwistedX

I'll take it in and ask them to check it, got an issue with the HVAC controls where the passenger side air direction doesnt go any higher than 2 bars where as the driver does. I'll see if they can check the alignment and raise my headlights too

Only the driver can control the air vents at the top, so the passenger side will not have that capability.

Raising headlights are easy and only requires a few minutes of your time and a screwdriver:
https://www.2addicts.com/forums/show....php?t=1062377

[nikman011]

14.6

[USA-RET]

FWIW, 2017 M240i w/ Dinan Stage 1. Most driving done is in comfort mode and 100% city. Very little continuous spirited driving, but do some spirited acceleration getting into traffic and away from stop lights.

Not a lot of "stop and go" (by that I mean -think rush-hour in a major metro area- bumper to bumper). My MPG's show 26.6 for the last three weeks. Lows in the 25's high in the 27's since owning 16 months.

Yours seems very low to me. I was getting 20MPG w/ our 6 cyl. 2008 Hyundai Santa Fe around town

[TajoMan]

Originally Posted by aerobod

Fuel consumption figures displayed in the on board computer are typically only derived from fuel flow metered at the injectors and are really only guidelines that aren’t that accurate. The easiest way to measure consumption somewhat accurately is to fill to the first click from a given fuel pump at your favourite fuel station, use most of the tank of fuel and then fill up at the same pump again. You should be within about 1% of fuel volume measured.

Distance travelled is another factor. The standard 245/35-18 rear tyres on my M240i over register speed by 4%, but register distance within 1% accuracy. The 225/45-18 winter tyres I use under register speed by 1% and also under register distance by 4% - all as verified by GPS and distance measurement between two accurately known points. In summary, don’t assume odometer distance is very accurate especially if you aren’t running stock rear tyre sizes.

I just keep a record of fuel fills divided by accurate distance measurements to understand my fuel usage.

Fuel consumption reading from CAN is actually fairly accurate.

I did numerous testing on our trucks (I work for truck manufacture), CAN reading and actual fuel consumption was within 5%.

If you think about it, it has to be accurate, mostly for emission issue.
Car needs to spray exact amount for the air it takes.
So they have to have good reading on air flow and fuel flow.

[aerobod]

Originally Posted by TajoMan

Fuel consumption reading from CAN is actually fairly accurate.

I did numerous testing on our trucks (I work for truck manufacture), CAN reading and actual fuel consumption was within 5%.

If you think about it, it has to be accurate, mostly for emission issue.
Car needs to spray exact amount for the air it takes.
So they have to have good reading on air flow and fuel flow.

The accuracy from an emissions perspective comes from trim adjustment in closed loop lambda operation. The instantaneous consumption from current fuel flow will be reasonably accurate, but the integral value over long periods may be less so. I’ve found a difference of up to 1 l/100km in the displayed long term fuel consumption vs the actual measured value from the fuel consumed, equating to about 2 US mpg. Perhaps I consider 10% variation in measured to displayed to be “inaccurate” when others see that variation as “accurate enough”?

[pz619]

Originally Posted by Shovelman

pz there is definitely something wrong there.

It crossed my mind for sure. My commute does kind of suck though.

[TajoMan]

Originally Posted by aerobod

The accuracy from an emissions perspective comes from trim adjustment in closed loop lambda operation. The instantaneous consumption from current fuel flow will be reasonably accurate, but the integral value over long periods may be less so. I’ve found a difference of up to 1 l/100km in the displayed long term fuel consumption vs the actual measured value from the fuel consumed, equating to about 2 US mpg. Perhaps I consider 10% variation in measured to displayed to be “inaccurate” when others see that variation as “accurate enough”?

Actual measured value is where I have more doubt.

I don't think people uses calibrated scale to measure their fuel consumption, normally.

Calculate fuel consumption based on fuel pump reading is as accurate as the CAN reading, if not less.

[cxp213]

Originally Posted by pz619

It crossed my mind for sure. My commute does kind of suck though.

Wait, you were in your car for over an hour to travel just 4 miles at an average of 4.2mph? I think I'd have just walked or taken a bike.

[tripitz]

Makes me feel a bit better! My new-to-me 228i is averaging 26.3mpg in 60% highway, 40% city, with some eco mode thrown in. I was actually disappointed with those numbers and wondered if I should have just bought the 235i instead. This is over 4k miles in the last 6 weeks since we bought it (we will be putting 25k per year on this car so gas mileage was a factor for getting the 4 cylinder). This is with a 6mt and essentially the "lightweight special" build too.

[aerobod]

Originally Posted by TajoMan

Actual measured value is where I have more doubt.

I don't think people uses calibrated scale to measure their fuel consumption, normally.

Calculate fuel consumption based on fuel pump reading is as accurate as the CAN reading, if not less.

From the engine mapping I’ve done on gasoline engines, the starting measurement for fuel flow is injector pulse width, there is no direct flow measurement. Although voltage, temperature and individual injector flow bias will dynamically adjust the pulse width to meet the mapped flows at given angina operating loads and speeds (before lambda closed loop adjustment through trim values), due to injector wear, injector solenoid hysteresis and inertia and small variations in fuel pressure, the metered amount based on pulse width isn’t very accurate when integrated over long periods, as the lambda accuracy is only obtained from the closed loop feedback.

Certainly in Canada fuel pumps have to be certified for accuracy on a frequent basis, so accurate measurement can be obtained over the long term (hundreds of litres), the accuracy gets better with larger volumes consumed. In the 1990s when I was a specialist for fuel station software systems, we would obtain 15C adjusted physical volume measurements within 0.1% of displayed values on the pump, often closer to tens of cc’s in 100 litres.

[Kothar]

93 octane always sport + city driving spirited avg 12 l/100km

[TajoMan]

Originally Posted by aerobod

From the engine mapping I’ve done on gasoline engines, the starting measurement for fuel flow is injector pulse width, there is no direct flow measurement. Although voltage, temperature and individual injector flow bias will dynamically adjust the pulse width to meet the mapped flows at given angina operating loads and speeds (before lambda closed loop adjustment through trim values), due to injector wear, injector solenoid hysteresis and inertia and small variations in fuel pressure, the metered amount based on pulse width isn’t very accurate when integrated over long periods, as the lambda accuracy is only obtained from the closed loop feedback.

Certainly in Canada fuel pumps have to be certified for accuracy on a frequent basis, so accurate measurement can be obtained over the long term (hundreds of litres), the accuracy gets better with larger volumes consumed. In the 1990s when I was a specialist for fuel station software systems, we would obtain 15C adjusted physical volume measurements within 0.1% of displayed values on the pump, often closer to tens of cc’s in 100 litres.

Yes, fuel pump is very accurate but there is no way to fill the fuel tank in a car consistently.
Fuel pump stops when the tank is almost full but that's inconsistent.
There is no way to fill to same level every time.
I've tired that and it varies couple of liters.

For the testing, I had to get a separate tank on a scale to measure fuel consumption.

[XutvJet]

Originally Posted by TwistedX

Just got a CPO M235i 8AT Convertible with 28k on the clock and I've averaging 16ish according to the car for 80/20 (city/hwy) driving. With the exception of occasional spirited acceleration I've kept it in comfort or sport(chassis only) and hardly ever go above 3k before it shifts. Haven't even had the car a week yet and already had to top it off.

Am I crazy or what cuz this thing is getting the same mpg as my 5000 pound X6 xDrive35i!!!!

What can I do or look at for helping city mpg? What do yall run for tire psi?

No, 16mpg is probably pretty normal given your short commute. The car never really gets up to temp which is a large reason why your MPGs suck. Your convertible weighs nearly 3,900lbs too.

MPG is highly variable depending on driving style, fuel grade, distance driven, cold engine/starts, lots of idling, city and highway driving, flat or hilly roads, windy and non-windy areas, etc.

Also, using minimal throttle and laboring along to get up to speed is actually worse on MPGs compared to using moderate throttle to get up to speed.

There's nothing wrong with you car. The DME is quite smart and there are tons of systems watching the fuel and emissions systems. If there was an issue, you'd have a CEL.

My typical commute is 11 miles each way on week days and I generally do 70% highway and 30% city. With my 6MT coupe, I typically see 20-22mpg. You do almost entirely city driving. That is the killer.