Team-BHP - View Single Post - How effective is the auto-cut mechanism of the fuel service stations?

Zappo · 22nd March 2006, 18:20

For the 1st time since last three or four fills I have started noting the FE of my car. Till now I always use to walk in and ask for 15 liters of diesel. That used to fill up the tank as afterwards the car's fuel gauge needle used to show FULL.

Now since last 3 times I asked them to fill up till auto-cut. The first time I was mentally prepared to fill more than 15liters. However to my astonishment I have filled 10.098 lters, 11.038 and 13.29 liters respectively on these three occassions. On each of these 3 occassions the car had more or less run the same kms. Now I noticed two things,

When the auto-cut shuts off the filler the fuel-gauge does not show the tank to be full!!!
More interestingly, the auto cut appears to be a crude mechanism. If you have the fuel level a little lower the filling up creates a lot of foam in the tank (due to height from which the fuel is falling, a-la pouring of beer in a glass) and hence the foam level rises faster and the moment it touches the filler nozzle/pipe the auto-cut jumps in. On the other hand if the fuel level is higher in the tank lesser foam is created and hence more fuel is filled until the filler pipe touches the actual fuel and auto-cut switches of the pump.

In such a case I reckon that even though auto-cut shuts off the pump the tank may not have necessarily got filled to the capacity. The reason why some people feel that they manage to push in so much more fuel (Fuel tank capacity measurement, how?) even after the "tank full".

Also, a more thoughtful matter is that if my observation is correct then the way we measure FE is also not very perfect as we now have a coefficient of fuel-foam factor in the equation.

Think about it!

22nd March 2006, 18:20	#1 (permalink)
Zappo Team-BHP Support Join Date: Oct 2005 Location: Hyderabad Posts: 3,181	How effective is the auto-cut mechanism of the fuel service stations? For the 1st time since last three or four fills I have started noting the FE of my car. Till now I always use to walk in and ask for 15 liters of diesel. That used to fill up the tank as afterwards the car's fuel gauge needle used to show FULL. Now since last 3 times I asked them to fill up till auto-cut. The first time I was mentally prepared to fill more than 15liters. However to my astonishment I have filled 10.098 lters, 11.038 and 13.29 liters respectively on these three occassions. On each of these 3 occassions the car had more or less run the same kms. Now I noticed two things, When the auto-cut shuts off the filler the fuel-gauge does not show the tank to be full!!! More interestingly, the auto cut appears to be a crude mechanism. If you have the fuel level a little lower the filling up creates a lot of foam in the tank (due to height from which the fuel is falling, a-la pouring of beer in a glass) and hence the foam level rises faster and the moment it touches the filler nozzle/pipe the auto-cut jumps in. On the other hand if the fuel level is higher in the tank lesser foam is created and hence more fuel is filled until the filler pipe touches the actual fuel and auto-cut switches of the pump. In such a case I reckon that even though auto-cut shuts off the pump the tank may not have necessarily got filled to the capacity. The reason why some people feel that they manage to push in so much more fuel (Fuel tank capacity measurement, how?) even after the "tank full". Also, a more thoughtful matter is that if my observation is correct then the way we measure FE is also not very perfect as we now have a coefficient of fuel-foam factor in the equation. Think about it! __________________ Announcements are important. Read the Advertising Announcement here. Classifieds section has its rules. Read here.