Here it stands ('94 M 1.5)... I have a set amount in the tank, say half full... trundle along for a bit then find a nice stretch of road to open up on... foot to the floor for a bit then ease off, suddenly to my horror i have a little over a quarter left! Thinking this cannot be, I trundle along for a while longer, seeing the fuel guage return to normal after about minute or two... Whats happening?

When You accelerate the system takse more fuel from the tank so that it has enough to feed the engine. When You stop accelerating the extra fuel is going back to the tank.

The efect is bigger on V6, but that is just the way it is.

Yea - the fuel sensor is at the front of the tank so hard acceleration will make the fuel slop to the back and the sensor will read a lower level. if I remember correctly it's also on the left, so hard right turns will knock it down too.

What's MORE frightening with the V6 is to really floor it a couple of times and realise that the gauge had dropped down and stayed down! Thank G*d they don't have an mpg gauge or I'd probably cack myself.......

M

[quote="Meridian"]Thank G*d they don't have an mpg gauge or I'd probably cack myself.......

M[/quote]

On the otherhand then we could save more money for upgrades...

Try this link for an explanation of how a standard fuel guage works and how it can frighten the bejeezus out of you when the needle seems to go into freefall inconsitently.....

http://auto.howstuffworks.com/fuel-gauge1.htm