Fuel costs often form a considerable part of total fleet expenses, especially for large companies. GPS monitoring systems for fuel control is the ultimate solution for optimization of the expenditure account. Fuel management system is based on data available from onboard computer or after-market fuel level sensors, installed in the fuel tank of a vehicle. Data transferred to tracking system allows detection of fuel thefts or unreasonably large fuel burn, thus helping to find ways to save 15% or more on fuel costs and increase fleet efficiency by 30% or more.