This is based around those cheap ebay half load cells and a dedicated load cell digital converter IC with a serial peripheral interface output. Each half cell will measure up to 50Kg so with four of them it'll measure up to 200Kg. The load cells don't have a flat base so I have to machine a steel cradle to hold each half cell and attach to the aluminium base. I started to machine relatively accurate bases before I found the load cells vary in thickness: on assembly I can use epoxy to bed the upper mechanical contact pads at the same time to get uniform contact on all four sensors. So the plan is to hook it up to an ESP8266 or ESP32 wifi microprocessor module which will interrogate the load cell interface and convert the weight readings over time into fuel consumption figures. An old android smartphone can be the wifi interface and display a webpage with the data. So once the unit is calibrated, I can zero the unit with an empty fuel container then place a full container with a known volume of fuel and the ESP8266 board can calculate the fuel density. After that, it's a matter of taking weights at set intervals and calculating the amount of fuel used over that interval as well as fuel remaining and consumption rate per hour. The load cell measures 35cm by 40cm or 14" by 16" in 6mm aluminium tread plate.