Posts about MPGs (fixed?)

[febul]

Originally Posted by whitebimmer09

I have 68k on it, I have all new injectors, all new plugs.

I mean other than the way I drive, is there something that can cause this?

The problem is I can get less, like 140 to a tank. Maybe I drive like an asshole and I don't realize it. Very possible.

Did you fix the problem? If so, how?

[whitebimmer09]

Originally Posted by febul

Did you fix the problem? If so, how?

I recently replaced all the injectors. Since I have owned it (3 months) I never really saw over 170 on a tank. I don't know if that was the cure all but I didn't change my driving habits. But I have not been turning the traction off either. I do shift on my own and I do keep the rpms high too so I can hear the nice over run. I was having difficulty starting before due to the injectors leaking but I couldn't imagine costing me like that. Putting it into perspective it really only is a 3-4 gallon difference.

I just was so shocked when I fueled up and saw my trip odo up that high (248 miles)

[fcman]

I get around 19mpg on about 60/40 city/hwy commute, but I drive pretty hard. Took a trip to Orlando over the winter and avg'd ~30mpg on the trip.

[DietTab]

fuelly.com

I average 21-22 in this car. higher 20s on freeway trips

[dvno]

Originally Posted by MightyMouseTech

It is just a standardised test to compare all cars, nothing more. Did you know the average speed of the "highway" rating is only 70 km/hr?

I can beat the highway rating when cruising, but around town with stop and go driving, I am hard pressed to get the "city" rating.

Also, for best fuel economy, you do NOT want to accelerate very gently. To get good FE, you need as much constant speed driving as possible. You want to accelerate to your cruising speed fairly quickly and then completely stop accelerating as soon as possible and cruise at a steady speed. Get the car into closed loop operation. If you are constantly accelerating, even slightly, you will be in open loop operation and the FE will be terrible.

This is even more important when driving a car with a turbo. While under boost, the engine needs to run richer to keep everything cool compared to a naturally aspirated engine. You need no boost, steady state driving to get into lean burn conditions. What makes this even worse is driving while the engine is warming up. The engine runs richer because the fuel is not getting fully atomised below operating temp, so the computer will run it a bit rich to compensate. So, driving with the engine not fully up to operating temp, constantly accelerating lightly will destroy the FE. You can't beat the laws of physics.

Maybe the OP should get an i3 to drive to work and back, they don't care about short trips, nothing to warm up.

Last week I upgraded from my '10 128 auto to a '11 DCT N55. I had also just extended my commute to work from 35 mi round trip to 62 round trip. In my 128, I started seeing close to 30 mpg (almost all highway). However, in the 135, I'm seeing closer to 23 or so. However, I have been babying the throttle, I'll try your method of getting to cruising speed more quickly and see what kind of results it yields!

Also, seeing all these posts helped put my mind at ease

[whitebimmer09]

Originally Posted by whitebimmer09

I recently replaced all the injectors. Since I have owned it (3 months) I never really saw over 170 on a tank. I don't know if that was the cure all but I didn't change my driving habits. But I have not been turning the traction off either. I do shift on my own and I do keep the rpms high too so I can hear the nice over run. I was having difficulty starting before due to the injectors leaking but I couldn't imagine costing me like that. Putting it into perspective it really only is a 3-4 gallon difference.

I just was so shocked when I fueled up and saw my trip odo up that high (248 miles)

Correction, the only time my wife drives the car she puts $20 in the tank. Wtf.
I thought I got good mileage...

[Ed P]

Originally Posted by Ed P

My previous car (which was up until two weeks ago ) was a 2006 Mazda MX-5, where I got about 31.5 mpg in a "normal" driving week, and about 34-35 pure highway. I knew I'd take a slight hit on mileage going to the 2013 135i of course.

First refill where it was all "normal" driving since I got the 135i was today. About 70%/30% hwy/city driving: 26.2-26.5 mpg. (26.5 if you calculate when the pump shut off; 26.2 if you calculate after I put in a little more to "top it off").

Highway driving (approx 70% of miles on this tank) is 65-80 mph, average of about 73. City driving (approx 30% of miles on this tank) is 0-50 mph, average of about 40.

I'm pretty happy with this. That means I'll get about 30+ mpg on the highway on a trip.

Just for info/comparison sake... my 2nd fillup:

24.5 mpg (a little more city driving than last fill up, hence the 2 mpg drop).

So:

1 - 26.5 MPG - 70/30 hwy/city
2 - 24.5 MPG - 60/40 hwy/city

[davis449]

Just a follow up from my earlier post. I compared my own DIS calculations (16 MPG) to the "math" method at the pump yesterday (15 MPG). So ~1 MPG off...

[MightyMouseTech]

One other thing I always do when I reset my avg FE with every fill up is to reset the avg speed at the same time. Pretty much a direct correlation between avg speed and avg FE.

In pure city driving, it is pretty much normal to see avg speed around 30 km/hr, which will be 12-13 L/100km.

It tells you a lot about exactly what kind of driving you are doing. There are big differences in "city" driving.

[DS/B MCS]

Measured my mpg based on my work commute this week. I'm in some moderate/heavy traffic most mornings, so here goes:
156 total miles
Average speed: 31.6
Computer mpg: 22.3
Mpg based on refill: 22.1

I don't really drive it hard, since there aren't many places to open it up. My last ride was an AP2 S2000 and the 135 gets better mileage around town and on the highway. Oh yeah, the 135i also has this wonderful thing call Torque.

[Ed P]

Originally Posted by Ed P

Just for info/comparison sake... my 2nd fillup:

24.5 mpg (a little more city driving than last fill up, hence the 2 mpg drop).

So:

1 - 26.5 MPG - 70/30 hwy/city
2 - 24.5 MPG - 60/40 hwy/city

I've had a few more fill-ups since the above; all are 26 MPG (give or take a fraction). 60/40 hwy/city.

Looking forward to my first road trip - should get over 30.

[Yeineken]

After upgrading from Potenza RTF's to the Hankook Evo2's... Holy MPG. averaging 35 mpg at around 65-70mph with cruise control on.

[JimD]

Originally Posted by Yeineken

After upgrading from Potenza RTF's to the Hankook Evo2's... Holy MPG. averaging 35 mpg at around 65-70mph with cruise control on.

I'm usually cruising at 75mph+ when on the interstate but I haven't seen 30 mpg yet. I average about 27mpg but even on trips I don't do that much better. If I cruised at 60 or 65, I'm sure I would get better mileage. Our cars are unusually high in Cd which increases the penalty we pay in mpg from higher speed travel.

[Kgolf31]

I averaged 30.9 mpg on a 900 mile trip fairly easily, not being over cautious or anything.

If I was careful I could easily get 32.

[Ed P]

Originally Posted by Yeineken

After upgrading from Potenza RTF's to the Hankook Evo2's... Holy MPG. averaging 35 mpg at around 65-70mph with cruise control on.

Wow that's great. Another reason I'm looking forward to replacing my run flats!

But I only have 5K miles on the car, so I have a ways to go.

How many miles do the OEM run flats last?

[e90post_user]

For people who claim mostly city driving - can you define your city driving? What is an average speed, how many stop lights on average you are hitting?
I drive in New York City, and that's my city driving - as far as the FE is concerned, the worst since I got the car was 14 MPG, but I rarely see more than 16 MPG in the city driving scenarios.

[Yeineken]

Originally Posted by Ed P

Wow that's great. Another reason I'm looking forward to replacing my run flats!

But I only have 5K miles on the car, so I have a ways to go.

How many miles do the OEM run flats last?

I maxed my rears out twice running them down to being bald and got a bubble in my front right tire I got only 15k out of the rears both times. Fronts are still full of tread. Decided it was just burning a hole in my pocket. The RFT's have very bad tread life.

[MightyMouseTech]

Originally Posted by e90post_user

For people who claim mostly city driving - can you define your city driving? What is an average speed, how many stop lights on average you are hitting?
I drive in New York City, and that's my city driving - as far as the FE is concerned, the worst since I got the car was 14 MPG, but I rarely see more than 16 MPG in the city driving scenarios.

That is why I also reset my avg speed with every fill up as well. Time spent idleing makes a huge difference in avg FE, and will change the avg speed as well. If my avg speed for a tank is less than 30 km/hr, I know the FE is going to be terrible.

[Billup]

I usually average about 24 to 27 depending on where I'm going. On a normal week its closer to 27 since I go from highway to country back roads with no lights.

[inline sex]

I'm getting an avg of 16.5 mpg on my commute which is basically all city driving. Distance to work is 4mi. Speed limit is 35 and I counted 12 traffic lights and one stop sign.
The best I've ever gotten on the hwy was 26mpg.

[Ed P]

Originally Posted by Ed P

I've had a few more fill-ups since the above; all are 26 MPG (give or take a fraction). 60/40 hwy/city.

Looking forward to my first road trip - should get over 30.

Quick Update...

Last 3 fillups:

26.x MPG (approx. 60/40 hwy/city)
26.x MPG (approx. 60/40 hwy/city)
27.5 MPG (approx. 70/30 hwy/city, but more traffic jams on the hwy than normal due to rain)

Not bad!

Car now has about 5300 miles on it.

[2012_135i]

Originally Posted by whitebimmer09

I have been reading several posts about what people get for gas mileage and I cannot believe the numbers. I see people posting 25 mpgs in a 135 with mostly city driving and I don't believe it. I am finding my own mileage pretty terrible. The way I judge my mpgs is resetting my trip odometer every fill up. I take the amount of miles on the odo and divide it by the number of gallons I put in.

I thing the people who are posting these great mpgs are relying on what their computer says and I don't think it is accurate.

I don't drive very hard and and from my math I get about 13 mpgs, no highway. It seems awful but I don't really know. I live in a hot climate and I have stop lights on my way in with 45 mile per hour roads in between. I only drive 6 miles to work and I don't step on it because nothing is heated up.

Does this sound normal? Going 170 miles between fill-ups?

I calculate my mileage the same way you do, not by looking at the computer, and I agree with you that people posting good mileage in the city must be looking at the computer read out which is not an accurate way to gauge your average mileage. You have to do the math at the pump.

I live in Honolulu (hot climate, lots of red lights like you) and get about the same mileage you do. I drive mostly to and from work, a distance of about 5 miles through the city, with occasional longer jaunts but still considered "city" driving. I get about 140 - 150 miles a tankful, averaging about 13-14 miles per gallon. I was so startled when I first got the car I took it in to BMW thinking something was wrong. Nope, normal they said [well, what else would they say]. The problem for us city drivers is that these cars are tuned for the autobahn, not going from stop light to stop light and idling at each one. I would love to be able to take the car on an interstate road trip and run through a couple tanks of gas to see what mileage I'd get but I didn't order the submersible option.

I know the car gets a lot better mileage on the highway because we do have one here (of a sort) and if I make a run up to the north shore and back which includes a stretch of highway and open country road my mileage improves considerably (maybe 18 mpg) but it's still hard to tell because a north shore trip is still a relatively short distance and the rest of the mileage on the tank is city. But I suspect that if I ran through a tank strictly on the highway I'd be able to get around 30 or so at the most economical speed.

After two years of driving around Oahu I've come to accept the crappy mileage I get in the city which is most of my driving. So, yeah, your situation sounds entirely normal to me.