[JonMad]

Well, I can comfirm two things.
1) The hidden OBC is very handy. I made full use of the 6.00 menu item showing left/right tank capacity and the 6.01 item which I think (!) shows total capacity.

Last night I had it very low indeed.
Tank L R S
0.0 0.4 0

i.e. 0.4 litres left. The normal range said I had about 5 miles to go, but watching the rate at which that last litre ticked away (and menu item 6.01 saying '0.9 / 1') I guessed right that I had enough gas to get to the gas station.

The most worrying part of the journey was a long right hander where the display sat at 0.0 0.0 0 for a long time, but I didn't run out at that point!

2) The tank capacity seems to be 62 litres (without looking in the manual). After filling up the hidden menu said

Tank L R S
27.5 35.0 62

and menu item 6.01 said '62.0 / 1'
and the range went back up to 738 miles.

So the price of this '61 and a bit' litre fill up? $115

[Pretender]

damn...I complained last time when I filled up for $55.

[powderhound]

JONMAD-

i am a new E90 owner - what menu are you referring to? Is it on the BC in the instrument cluster or on thee IDrive? Sounds cool I would like to chekc it out.

[Hej]

What is 'OBC'?

[325Driver]

Originally Posted by Hej

What is 'OBC'?

On Board Computer

[ward]

does it really kill you to stop for gas 4 more times over the life of the car

[txusa03]

Originally Posted by JonMad

Well, I can comfirm two things.
1) The hidden OBC is very handy. I made full use of the 6.00 menu item showing left/right tank capacity and the 6.01 item which I think (!) shows total capacity.

Last night I had it very low indeed.
Tank L R S
0.0 0.4 0

i.e. 0.4 litres left. The normal range said I had about 5 miles to go, but watching the rate at which that last litre ticked away (and menu item 6.01 saying '0.9 / 1') I guessed right that I had enough gas to get to the gas station.

The most worrying part of the journey was a long right hander where the display sat at 0.0 0.0 0 for a long time, but I didn't run out at that point!

2) The tank capacity seems to be 62 litres (without looking in the manual). After filling up the hidden menu said

Tank L R S
27.5 35.0 62

and menu item 6.01 said '62.0 / 1'
and the range went back up to 738 miles.

So the price of this '61 and a bit' litre fill up? $115

would that harm your engine by going that low? Are you trying to experiment and share your story or do you always drain the tank before refilling? Why risk being stranded? What if the station you pull up to ran out of super unleaded? Just some thoughts...

edit: noticed you have a diesel...so what if the station you pull up to ran out of diesel?

[JamieA]

I had an interesting ride back into Adelaide yesterday where I was running very light on fuel. Luckily it was a down hill run on the freeway, but there was one stage I was seriously worried I would run out of fuel. The needle was between the last and empty notches. Filled it up with 58 litres... so apparently there were 4 to spare...

That was an $AU80 fill up with 98RON super premium fuel (BP Ultimate 98). Luckily my company pays for my fuel...

[txusa03]

Originally Posted by JamieA

I had an interesting ride back into Adelaide yesterday where I was running very light on fuel. Luckily it was a down hill run on the freeway, but there was one stage I was seriously worried I would run out of fuel. The needle was between the last and empty notches. Filled it up with 58 litres... so apparently there were 4 to spare...

That was an $AU80 fill up with 98RON super premium fuel (BP Ultimate 98). Luckily my company pays for my fuel...

since I have a manual, I can put it in Neutral and let it ride down hill. But I tried not to but myself in those sort of stressful moment.

[JonMad]

Hi again

would that harm your engine by going that low? Are you trying to experiment and share your story or do you always drain the tank before refilling? Why risk being stranded?

- Not sure, possibly, but I wouldn't know how - crap in the system maybe?
- Was just curious.
- No, normally fill up when it gets down to about 60 miles range shown, but only because that easily covers a return trip to work and one of the cheapest garages is near my house.
- wasn't in a rush and was curious. not something I always do.

so what if the station you pull up to ran out of diesel?

I'd have driven very lightly the two miles to another one, and if that had also run out I'd have driven very, very lightly the half mile home then got in my other car and bought a can of the stuff

I did slow down to a 60mph cruise to conserve the gas, and on a downhill and round a tight off-ramp I did coast it, so it wasn't an entirely free-from-nerves test!

what menu are you referring to?

Do a search for 'hidden OBC' - you have to hold down the tripmeter reset button to get into it, then enter a code. There's a thread with full instructions somewhere.

does it really kill you to stop for gas 4 more times over the life of the car

nope but it was good to know that the bottom of the tank is not reached before the needle hits the 'empty mark' of the dial - in fact, it went marginally over, but there was not clear air between the needle and the empty mark, fwiw.

[JamieA]

Originally Posted by txusa03

since I have a manual, I can put it in Neutral and let it ride down hill. But I tried not to but myself in those sort of stressful moment.

I agree. I wasn't happy about it. I have never run out of fuel in my entire driving career, and I didn't want this to be the first time...

[voltron1011]

Originally Posted by txusa03

since I have a manual, I can put it in Neutral and let it ride down hill. But I tried not to but myself in those sort of stressful moment.

The e90 actually consumes more fuel idling than it does if you left it in gear going down hills. Just look at your MPG gauge and you'll notice that when left in gear, your MPG needle is maxed out to inifinity. If you leave it in neutral, you'll see that you are getting aroung 40 mpg's.
The fuel injectors actually shut off as long as you have it in gear and are using momentum/gravity to keep it running.

[txusa03]

Originally Posted by voltron1011

The e90 actually consumes more fuel idling than it does if you left it in gear going down hills. Just look at your MPG gauge and you'll notice that when left in gear, your MPG needle is maxed out to inifinity. If you leave it in neutral, you'll see that you are getting aroung 40 mpg's.
The fuel injectors actually shut off as long as you have it in gear and are using momentum/gravity to keep it running.

I would have to test this when I go down hill (which is difficult to test because I live in flatland). But not to worry, we have long bridges I can test down hill. What you described is actually true when I put the car in cost on a flat drive, I do see the MPG energy needle moving away from 50. Why would the Fuel injection not shut off when in neutral? Very interesting...

[Ghunger]

Originally Posted by txusa03

I would have to test this when I go down hill (which is difficult to test because I live in flatland). But not to worry, we have long bridges I can test down hill. What you described is actually true when I put the car in cost on a flat drive, I do see the MPG energy needle moving away from 50. Why would the Fuel injection not shut off when in neutral? Very interesting...

Well, something's gotta keep the engine running. When it's in gear the drivetrain is keeping the engine turning, when it's in neutral, the car has to add fuel to keep the engine running.

[txusa03]

Originally Posted by Ghunger

Well, something's gotta keep the engine running. When it's in gear the drivetrain is keeping the engine turning, when it's in neutral, the car has to add fuel to keep the engine running.

I think I get it now, I really do not need to test down hill. From what you are saying, this is how I pictured this. When you are in neutral, your wheels and drive train are spinning but not connect/engage to the engine, so the engine is on its own and will stop running since nothing is keeping it running so the fuel is needed.

On the other hand, if you are in gear and you do not give the car any gas and just coast, the wheels' momentum continue to drive the engine. Easy enough now that you mentioned it. Me no mechanics and I did not do too well in physics back in college (those days are long gone).

[dude007]

There is one more variable in this picture:
Engaged engine slows you down much more than cruising in Neutral. At the end it still may be more economical to go 40+ mpg for lets say 1 mile than 60 or what ever mpg in gear for 500 feet.
Just a thought

[timoth31]

Originally Posted by JonMad

Well, I can comfirm two things.
1) The hidden OBC is very handy. I made full use of the 6.00 menu item showing left/right tank capacity and the 6.01 item which I think (!) shows total capacity.

Last night I had it very low indeed.
Tank L R S
0.0 0.4 0

i.e. 0.4 litres left. The normal range said I had about 5 miles to go, but watching the rate at which that last litre ticked away (and menu item 6.01 saying '0.9 / 1') I guessed right that I had enough gas to get to the gas station.

The most worrying part of the journey was a long right hander where the display sat at 0.0 0.0 0 for a long time, but I didn't run out at that point!

2) The tank capacity seems to be 62 litres (without looking in the manual). After filling up the hidden menu said

Tank L R S
27.5 35.0 62

and menu item 6.01 said '62.0 / 1'
and the range went back up to 738 miles.

So the price of this '61 and a bit' litre fill up? $115

Do people really think about miles, not km, in the UK? While they are buying petrol by the litre?

[ward]

Originally Posted by timoth31

Do people really think about miles, not km, in the UK? While they are buying petrol by the litre?

yes,

that's why they call it the "english" system as opposed to the metric system

[JonMad]

All the signs and speed limits are in miles, so yep. And it's still miles per gallon - we don't work in l/100km (or miles/litre!)

[poldim]

Originally Posted by voltron1011

The e90 actually consumes more fuel idling than it does if you left it in gear going down hills. Just look at your MPG gauge and you'll notice that when left in gear, your MPG needle is maxed out to inifinity. If you leave it in neutral, you'll see that you are getting aroung 40 mpg's.
The fuel injectors actually shut off as long as you have it in gear and are using momentum/gravity to keep it running.

No. The fuel injectors do not shut off.

When the ECU sees the engine is pulling vacuum at RPMs higher than idle, it uses a different part of the fuel map which is a lot lower than the standard map. Turning "off" the injector, also know as not sending it the injector pulse, would create an enormous amount of stress due to the force coming from the other end of the drivetrain. Instead, the lower fuel map that is used just give it enough fuel for combustion to create an aid in pushing the pistons over. This nearly eliminates the stress and greatly lowers the fuel consumption.


Coasting, does infact consume more gas than keeping it in gear and letting go of the gas pedal. This action however slows the car down a great deal. What you should do is keep it in gear and just slightly give it some throttle so that you are not using the engine to slow yourself down the grade.

[txusa03]

Originally Posted by dude007

There is one more variable in this picture:
Engaged engine slows you down much more than cruising in Neutral. At the end it still may be more economical to go 40+ mpg for lets say 1 mile than 60 or what ever mpg in gear for 500 feet.
Just a thought

I agreed with you here too, excellent point.

[poldim]

Originally Posted by txusa03

I would have to test this when I go down hill (which is difficult to test because I live in flatland). But not to worry, we have long bridges I can test down hill. What you described is actually true when I put the car in cost on a flat drive, I do see the MPG energy needle moving away from 50. Why would the Fuel injection not shut off when in neutral? Very interesting...

If you supply no fuel, you get no combustion, without combustion, you get no turnover. Hence your engine would turn off.

Idling an engine for 30 seconds is roughly equivalent to the amount of fuel spent to start it. So if you are afraid of running out, turn off your engine and coast to a stop light if you think you will be there for longer than 30 seconds.