How do they test a fuel tank for MOT?

I don't test for water in my fuel tank. I put in a bottle of dry gas and it's good to go. If you think someone may have purposely dumped water down your fill neck, you're going to have to syphon it...

In Vietnam the US Army's M48A3 Patton tank held approximately 300 gallons of diesel fuel.

Take a sample out and check following;Colour - Petrol is almost clear, diesel is more yellowySmell - Diesel and Petrol both have distinctively different smells, only way is if you get a sample of...

Fuel Problem. Check and ensure that you are not trying to put diesel in the vehicle, diesel nozzles are larger diameter to prevent accidentally putting diesel in a vehicle that requires gasoline....

Just over ten gallons.