A working vehicle according to the present invention is configured with a fuel tank, a fuel sensor for detecting an amount of fuel stored in the fuel tank, and an informing device (a controller, informing switch, and speaker) for informing the stored amount of fuel detected by the fuel sensor, by changing the informing pattern in response to this stored amount of fuel. The working vehicle is also configured with an exhaust gas purification system for purifying exhaust gas using urea water, a urea water tank, a urea water sensor for detecting the amount of urea water stored in the urea water tank, and an informing device (the controller, informing switch, and speaker) for informing a stored amount of urea water detected by the urea water sensor, by changing the informing pattern in response to this stored amount of urea water.

In one aspect, a vehicle and associated method includes a liquid reservoir, a first sensor mounted in front of the liquid reservoir, a second sensor mounted behind the liquid reservoir, a memory storing instructions, at least one processor configured to access the memory and receive a plurality of inputs from the first and second sensors, the at least one processor being configured to compare a first sensor output from the first sensor to a second sensor output from the second sensor, and based on a determined difference between the first and second sensor outputs, initiate a notification of a detected leak in the liquid reservoir.

In accordance with at least one aspect of this disclosure, a fuel quantity measurement system includes, one or more pressure sensors are configured to operatively connect external to a fuel volume of a fuel tank, and can be operative to sense and output a signal indicative of a pressure outside of the fuel volume. One or more hollow pressure tubes can be configured to be disposed in the fuel volume in the fuel tank. The one or more hollow tubes can have a first end in fluid communication with the fuel volume and a second end configured to be sealed against an ambient environment external to the fuel tank. One or more temperature sensors can be configured to operatively connect within the fuel tank, operative to sense and output a signal indicative of a temperature of the fuel tank.

Systems, methods, devices, and models determining fuel level in vehicles are described. Fuel tank capacity often extends beyond what can be measured by a fuel level sensor. Herein, fuel level data is augmented with fuel consumption data or fuel consumption rate to estimate a fuel level in a fuel tank when a fuel level sensor reads 100%. Fuel consumed until the fuel level sensor reads less than 100% can be added to measurable capacity of the tank to determine an initial volume of fuel in the tank.