[ON325i]

Hello all, I'm new to the BMW world and just finished the break-in for my Jet Black Auto/Sports Pkg 325i. Let me just say I am loving it every single aspect of it~~

In any case, I have a question about the fuel consumption behaviour of the car. When I gradually accelerate to 70km/h lets say, the L/100km needle tends to stick around the 20 zone all the way. However, if I let go of the gas pedal completely and step on it quickly again, it will maintain at the much lower consumption rate. I wonder if this has anything to do with the computer predicting what you are trying to do and thus assigning different power, one being starting from 0->70 and one starting from 50->70. Or is it just an illusion~

In any case, just something I notice while crying over the gas price and trying to figure out a good way to reduce gas usage during post-7k-rpm breaks.

[David328M-Sport]

i'm not so sure that the fuel consumption meter is the most reliable indicator. it seems to kind of work but once i drive off, it moves over all the way to the right but once my desired speed is reached it moves down and if i dont pump the go pedal to hashly, it tends to hover over the 5 - 10 mark.

i dont take too much notice of the needle myself. you can zero your average fuel consumption display and check your almost instant fuel consumption that way if that's what you are after.

otherwise the meter is a general guide to me.

[JamieA]

I thought those needles were just disguised vacuum gauges and therefore not particularly accurate. (I would be interested if anyone knew exactly how that needle worked)

I agree with David that the computer would be more accurate because it would be based on information directly from the engine management system.

[fredtoo]

Originally Posted by JamieA

I thought those needles were just disguised vacuum gauges and therefore not particularly accurate. (I would be interested if anyone knew exactly how that needle worked)

I agree with David that the computer would be more accurate because it would be based on information directly from the engine management system.

I am not sure that these are vacuum gages. I did not think the valvetronic engine created manifold vacuum, and I know that that a turbo deisel engine has no engine vacuum.

[JamieA]

Originally Posted by fredtoo

I am not sure that these are vacuum gages. I did not think the valvetronic engine created manifold vacuum, and I know that that a turbo deisel engine has no engine vacuum.

Thanks for that... makes sense.

Perhaps the inconsistent movement of the needle is related to the electronic throttle then.

[billgti]

Originally Posted by coreslogic

Hello all, I'm new to the BMW world and just finished the break-in for my Jet Black Auto/Sports Pkg 325i. Let me just say I am loving it every single aspect of it~~

In any case, I have a question about the fuel consumption behaviour of the car. When I gradually accelerate to 70km/h lets say, the L/100km needle tends to stick around the 20 zone all the way. However, if I let go of the gas pedal completely and step on it quickly again, it will maintain at the much lower consumption rate. I wonder if this has anything to do with the computer predicting what you are trying to do and thus assigning different power, one being starting from 0->70 and one starting from 50->70. Or is it just an illusion~

In any case, just something I notice while crying over the gas price and trying to figure out a good way to reduce gas usage during post-7k-rpm breaks.

i've noticed this too with my gas mileage needle. i remember going downhill with my foot lightly on the gas going 85mph and the needle pointed 20mpg (no way the mileage is that bad). on the next hill while going up hill at 85mph, i got the needle to stay constant at 25mpg. something's funny about that meter but most of the time if u're cruising at constant hwy speed, it's at 30mpg and if u're accelerating, it goes to 12 mpg (the lowest)