Hmm, very strange. Is this a pattern or something you observed once? I fuel at Shell nearly all the time and they have never given me a reason to think they are cutting corners. I always fill up my tank though - mostly because it makes it easy to monitor my fuel economy.

Noticed the same discrepancy at shell adams. We should name and shame them.

One feasible way to con you like that is to doctor the pump so that it serves up less volume that it displays. You can detect that by asking them to fill up a fixed volume container. Unless of course they have a secret switch they flip when such requests are made in order to "reset" the pump.

For comparison you need to fuel elsewhere i guess..

well the only trully method to meusure is to use a fixed volume container because u cannot truly tell your tank balance by simply looking at the time the light comes on.To understand this i normaly fuel full tank and can drive 100km before the needles moves even 1/10 of a mm.

Has been observed- usually avoid these stations after these posts

http://www.wazua.co.ke/forum.aspx?g=posts&t=19256&p=2

I've heard that the time one fuels up matters. Fueling in the morning (coldest time) is best than when temperatures are high. Something about expansion.

But those fuel tanks are buried deep in the ground. Are there really any differences in temp (and density/volume) kwa underground tank at different times of the day when you are fueling? Research says that the soil temp remains constant 30cm below the surface.

@Mukiri....how would I know the correct consumption of the 1,500cc car if its tank has always been pumped with a fake No. of Ltrs?

I am not a competitor & if I was one I'd have ensured the word "Shell" appears in my thread title.I was actually suprised the same issue was discussed on Wazua last year by several other people
http://www.wazua.co.ke/f...sts&t=19256&p=2

How is that? Do you mean to talk about increased mass? A tank full of petrol raises my car's overall mass by less than 3%, how much difference do you reckon that makes to fuel economy? What do you have to say about vaporization losses that occur to a greater extent in mostly empty tanks? My opinion is that such factors have such a small impact on fuel economy that they're not worth obsessing about. Some people won't even give their neighbor a lift because they think it will hurt their fuel economy! And by the way the reason I monitor my fuel consumption so closely is just so I make sure I can explain it. If I drive aggressively, which I do sometimes, I expect to burn more gas. If I am easy on the accelerator, which I often am, I expect to burn less. If that is not happening then I investigate. This knowledge is more important to me than the money I might save and the time I might waste by fueling up a quarter tank every time.

PS: Fuel economy for me is not the be all and end all of driving, I care for the fun too and I appreciate that it comes at the expense of spending more on petrol. But so what? It's the same with the rest of life - win some lose some.