9.9 mpg

I think those getting 14+ mpg in the "city" still don't have commutes/traffic like real congested cities with lots of traffic jams, stop and go traffic and speeds rarely above 40 mph. I got 10 mpg in mostly city driving but get 13 when I started using start/stop (which I thought I'd hate but come to love and use it all the time).

DavidZ wrote

I think those getting 14+ mpg in the "city" still don't have commutes/traffic like real congested cities with lots of traffic jams, stop and go traffic and speeds rarely above 40 mph. I got 10 mpg in mostly city driving but get 13 when I started using start/stop (which I thought I'd hate but come to love and use it all the time).

My congestion related to 14.5mpg is moderate. Definitely not as bad as sitting in traffic in the West End of DC around rush hour or parking on the 405 at 4:30 PM in Los Angeles, but enough traffic where a 6 mile commute takes 20 minutes.

All I want to know is if the 1/2 or 3/4 throttle or brisk acceleration + short shifting really improves gas mileage
and Im assuming short shifting at 2.5k - 3k rpm?

abehwang wrote

All I want to know is if the 1/2 or 3/4 throttle or brisk acceleration + short shifting really improves gas mileage
and Im assuming short shifting at 2.5k - 3k rpm?

For me = 1/2 throttle shifting between 3-4K. This improved my city mileage by 2.5 mpg.

Shifting below 3k??? What a waste? Trying to drive your car like a Prius? This car has NO torque OR HP below 3k. Am I too hard on her? I never shift below 4k and the car seems to shift more smoothly, especially 1-2.
So, I filled up the car and the mileage counter was almost zero, single digits. I added 16.7 gallons. SO, is the manual wrong??? Manual says the fuel capacity is 16.6 gal INCLUDING a 3 gal reserve. Has anyone ever added 17 or 18 gal + ???

rye m3 wrote

I never shift below 4k and the car seems to shift more smoothly, especially 1-2.

Agree...the one thing that stops me from routinely shifting above 4K is my catless set-up. I love the sound, but on the street, it's a bit aggressive and serves to get more jack*sses to try and race me. Of course, even if I don't race, I'll be the one in trouble with Mr. Law due to the exhaust note and the car itself.

It's a pretty well known fact that the mileage in the M3 sucks. The reason the mileage sucks is because you never hit the highway. I do about 75% city and 25% highway and get 14-15 mpg.

I saw a video of the BMW efficient dynamics shift indicator you can have programmed. It literally shifts way lower than 3,000 rpm. They suggest 5th gear at less than 40 mph if I remember correctly. 3rd gear at 20 something mpg.

This might help your mileage. Just watching the video helped mine.

The video is in here somewhere:
http://www.m3post.com/forums/showthread.php?t=568643

rye m3 wrote

Shifting below 3k??? What a waste? Trying to drive your car like a Prius? This car has NO torque OR HP below 3k. Am I too hard on her? I never shift below 4k and the car seems to shift more smoothly, especially 1-2.
So, I filled up the car and the mileage counter was almost zero, single digits. I added 16.7 gallons. SO, is the manual wrong??? Manual says the fuel capacity is 16.6 gal INCLUDING a 3 gal reserve. Has anyone ever added 17 or 18 gal + ???

It's possible that the extra fuel is not in the tank but within the hose/tube leading to the tank?

Titanium Silver wrote

I saw a video of the BMW efficient dynamics shift indicator you can have programmed. It literally shifts way lower than 3,000 rpm. They suggest 5th gear at less than 40 mph if I remember correctly. 3rd gear at 20 something mpg.

This might help your mileage. Just watching the video helped mine.

Does this assume hitting the high gears while accelerating or if staying at a static speed? I accelerate by shifting between 3-4K, but if I want to stay at an mph, like 30, I upshift to the highest gear that allows me to keep forward momentum at the requisite speed.

rye m3 wrote

Shifting below 3k??? What a waste? Trying to drive your car like a Prius? This car has NO torque OR HP below 3k. Am I too hard on her? I never shift below 4k and the car seems to shift more smoothly, especially 1-2.
So, I filled up the car and the mileage counter was almost zero, single digits. I added 16.7 gallons. SO, is the manual wrong??? Manual says the fuel capacity is 16.6 gal INCLUDING a 3 gal reserve. Has anyone ever added 17 or 18 gal + ???

i think u mean the 3 gal reserve is included in the 16.6 gal....NOT IN ADDITION to 16.6 gal...which would make it a 19.6 gal tank....because everytime i hit a 1/4 tank remaining on the fuel guage, the idrive light turns on indication im running on "reserve"

richpuer wrote

i think u mean the 3 gal reserve is included in the 16.6 gal....NOT IN ADDITION to 16.6 gal...which would make it a 19.6 gal tank....because everytime i hit a 1/4 tank remaining on the fuel guage, the idrive light turns on indication im running on "reserve"

Does this mean that when the reserve light comes on we only have 3 gallons left?
I don't understand the concept of a reserve tank... is it even a separate tank?

abehwang wrote

Does this mean that when the reserve light comes on we only have 3 gallons left?

Yup

Well, the question remains. The manual says the total includes the reserve, but I've clearly filled in excess of the total, so is the reserve in addition?

richpuer wrote

i think u mean the 3 gal reserve is included in the 16.6 gal....NOT IN ADDITION to 16.6 gal...which would make it a 19.6 gal tank....because everytime i hit a 1/4 tank remaining on the fuel guage, the idrive light turns on indication im running on "reserve"

The latter would mean that the tank is a whopping 13 gallons, which is really crap.

rye m3 wrote

The latter would mean that the tank is a whopping 13 gallons, which is really crap.

The tank is 16.6 gal, including what is called a "reserve", but is technically not. There is no separate reserve tank. A small amount over this could, I suppose, reside in the filler tube.

Tank is 16.6 gallons. When it hits empty, it's empty !!! hahaha
there is no extra gas after empty on your guage

abehwang wrote

All I want to know is if the 1/2 or 3/4 throttle or brisk acceleration + short shifting really improves gas mileage
and Im assuming short shifting at 2.5k - 3k rpm?

Don't overthink the throttle input too much. Just brisk acceleration to cruising speed, then short shift the next few gears.

There were some good explanations earlier in this thread, but basically, the engine is more efficient during this type of acceleration.

Because of this thread (and my recent entry into M3 world), I did a somewhat non-scientific test. On one tank of gas I accelerated slowly, drove very conservatively, and always left the car in automatic drive mode. I had the Power button selected. I got just under 12 MPG for the tank. For the second tank, I left almost everything exactly the same - even filled up at the same station, same pump, same day of the week, and drove the same type of miles I drove the previous week (i.e. same blend of city/highway). The only thing I changed was my rate of acceleration from a stop: I got to speed quickly, then leveled off at the speed limit. I averaged 15 MPG.

My conclusion: do what lots of these posters say - accelerate quickly, then drive normally. It seems to be working. And if it doesn't hold up long term, at least I had way more fun!

Either way, I knew the MPG on this car wasn't great when I bought it, so I figured a hefty fuel cost into my monthly car expense before buying the car. It hasn't been as expensive as I budgeted, so I'm happy with that.

Maybe the next M3 quintuple-turbo hybrid diesel will be better. But people are gonna miss that V8...

GregW / Oregon wrote

The tank is 16.6 gal, including what is called a "reserve", but is technically not. There is no separate reserve tank. A small amount over this could, I suppose, reside in the filler tube.

However, I put in over 16.6 gallons and the mileage indicator was not to zero. I would just be astounded given the idiots in the world today, that the car really runs out of gas exactly when the gauge shows empty. It would be contrary to every other car I've ever owned. There is just such a huge difference between a car with a 13 gallon tank and a 3 gallon reserve and a 16 gallon tank with a reserve. A 13 gallon tank would have to be one of the smallest in production car. I would object a lot less to the mileage if I knew the car held another 3 gallons of gas.

GregW / Oregon wrote

The tank is 16.6 gal, including what is called a "reserve", but is technically not. There is no separate reserve tank. A small amount over this could, I suppose, reside in the filler tube.

Just curious without being offensive, you've obviously posted here a lot - how do you know that the tank is 16.6 gallons, other than that's what it says in the manual?

DavidZ wrote

I think those getting 14+ mpg in the "city" still don't have commutes/traffic like real congested cities with lots of traffic jams, stop and go traffic and speeds rarely above 40 mph. I got 10 mpg in mostly city driving but get 13 when I started using start/stop (which I thought I'd hate but come to love and use it all the time).

The greater L.A. area and traffic are synonomous. It's all about HOW you drive.