Average fuel consumption on the 1M

[RJKmetal]

Can someone explain to me why is town driving so bad for consumption? I seem to get the same figures sitting in a traffic jam as hammering round some back roads!! I was stuck in a jam last week for half an hour and the average consumption for that tank of fuel just plummeted. Couldn't take my eyes off the damn screen!!

[EmmDrei]

Originally Posted by RJKmetal

Can someone explain to me why is town driving so bad for consumption? I seem to get the same figures sitting in a traffic jam as hammering round some back roads!! I was stuck in a jam last week for half an hour and the average consumption for that tank of fuel just plummeted. Couldn't take my eyes off the damn screen!!

Simple math. You guys go with miles per gallon. So you are travelling zero miles but are using N gallon(s). Actually a division by zero (which is mathematically impossible), but logic tells us, that the figure will skyrocket the longer we sit with an idling engine. That's the simple reason why city traffic causes a higher consumption. The driving pattern will create a mathematical disadvantage.

I can play with my fuel consumption. My minimum so far 10,4L/100km. On a 1.200km round trip. Stretches of unlimited Autobahn (with 240km/h max due to winter tires), but most of it was limited highways and smaller roads. Basically cruising. I'm sure, I could get it below 10L/100km if I actually tried.

Regular everyday commuting I average around 13,5L/100km. Will go up and down depending on things such as a/c on or off. 3/4 are country roads, 1/4 is city driving. That is when driving in "fun mode". If I drive the same route with a little less aggression and a little more "eco", I can do it in 11,5L/100km. Less fun, but not cruising.

My max so far was almost 20L/100km on the Northern Loop. But there again, I'm sure, that that can also be maxed.

[Japi]

my is 10,3 litre/100km

[burnsniper]

About 750 miles in I am getting right around 23 mpg in what I would call "suburban driving" - not really stop and go but 35 to 55 mph speed limits and a 1/2 mile or more between lights.

[ZCP M3]

On the trip from PCD to STL, I averaged 23.7mpg at 85mph.

Been around 22 lately with mostly city driving.

[ZCP M3]

Originally Posted by RJKmetal

Can someone explain to me why is town driving so bad for consumption? I seem to get the same figures sitting in a traffic jam as hammering round some back roads!! I was stuck in a jam last week for half an hour and the average consumption for that tank of fuel just plummeted. Couldn't take my eyes off the damn screen!!

Youre using fuel without moving anywhere. Your fuel economy is 0mpg.

Also accelerating up to speed uses the most fuel.

[wizz72]

During my run in period i had 28.9 mpg over 1000 miles,now after 2500 miles im at 26.9,i run it on 97/98 ron in the UK..or 99 in Belgium which it liked...a lot

[RJKmetal]

Thanks for your help guys. I think I am getting obsessed with

[RJKmetal]

Sorry. Was saying think I am getting obsessed with fuel economy which is clearly not the point with this amazing car of ours! Thanks again.

[rapter]

I consistently show 8.1 l/100km and burn between 390-410km (range) on a single tank.

Usually fill up 48 literes

[P1]

Are these hand calculated, or all readouts from the trip computer? And how accurate is the latter for those who have checked?

[l888apex]

Since the run in service (about 3200 miles) I'm at 18.6 mpg average. Mostly city/suburbs with some highway mixed in. Usually have the M button on and drive accordingly.

[bayer]

Originally Posted by P1et

Are these hand calculated, or all readouts from the trip computer? And how accurate is the latter for those who have checked?

Hand calculated at each fill up for me, I have never reset my trip computer for MPG, so it just shows "lifetime", which will always be different since it is averaging over larger sample size. The initial few were very close however.

[bayer]

Originally Posted by RJKmetal

Sorry. Was saying think I am getting obsessed with fuel economy which is clearly not the point with this amazing car of ours! Thanks again.

An interesting thread! I only track it because its part of my OCD (it knows no bounds), I like to know, I could care less at the number for the 1M

[robertm]

Originally Posted by l888apex

Since the run in service (about 3200 miles) I'm at 18.6 mpg average. Mostly city/suburbs with some highway mixed in. Usually have the M button on and drive accordingly.

Mines about the same. I was running about 22 avg until someone tricked me into playing with that dam M button. Now it's always activated and I was shocked to see how much my econ has been effected as a result. I'm about 18 mpg now doing city/hwy.

[Mnime]

Originally Posted by AM1N

I guess my foot is a bit more heavy: 15.6 mpg on avg! 7800 miles

Same here...in town about 16 mpg. Highway I was able to get 30 mpg obeying the speed limit but if I drive like I normally would on the highway it is more like 27.

[P1]

Originally Posted by Delrin

Hand calculated at each fill up for me, I have never reset my trip computer for MPG, so it just shows "lifetime", which will always be different since it is averaging over larger sample size. The initial few were very close however.

I drive a 3/4 ton Dodge diesel and it's easy to hand calculate as I can fill the diesel fuel right to the neck. However, in my wife's 135i, this would probably not be so easy. How can one ensure correct numbers when hand calculating the MPG?

[M3 Adjuster]

Originally Posted by robertm

Mines about the same. I was running about 22 avg until someone tricked me into playing with that dam M button. Now it's always activated and I was shocked to see how much my econ has been effected as a result. I'm about 18 mpg now doing city/hwy.

Busy Saturday? Toy Run at ECR..........

[M3 Adjuster]

Originally Posted by Delrin

Hand calculated at each fill up for me, I have never reset my trip computer for MPG, so it just shows "lifetime", which will always be different since it is averaging over larger sample size. The initial few were very close however.

haven't reset mine either... haven't needed to measure anything yet.


As far as the consumption... I used to track my economy and keep it in a notebook.. My E30 M3 was always right in line with my calculations.. so i stopped doing this years ago. I am sure the 1M OBC is very accurate.

[bayer]

Originally Posted by P1et

I drive a 3/4 ton Dodge diesel and it's easy to hand calculate as I can fill the diesel fuel right to the neck. However, in my wife's 135i, this would probably not be so easy. How can one ensure correct numbers when hand calculating the MPG?

I don't think you ever really can, there is just too much error and noise in the system. Not every gas pump pumps 1:1, sometimes more, usually less. Pumps click off short. MPG calcuation is an approximation. In some aspects the trip computer is probably more accurate, as I think it acutally can tell how much fuel is being sent to the engine. I don't know this for sure.

Just to clarify, by hand calculation, I mean I just take gallons pumped in (to first pump click), note the mileage and do the math.

[bayer]

Originally Posted by M3 Adjuster

I used to track my economy and keep it in a notebook.. My E30 M3 was always right in line with my calculations.. so i stopped doing this years ago. I am sure the 1M OBC is very accurate.

The first 2 tanks on the 1M were within a tenth of MPG to my hand calculation, so I would agree with that!

[Soulchi]

Originally Posted by rapter

I consistently show 8.1 l/100km and burn between 390-410km (range) on a single tank.

Usually fill up 48 literes

I have 14,8 liters/100km and I am driving not too sporty because I have driven 1200km for now.

Will it decrease???