The study looked at how the way a driver uses gears in a vehicle affects fuel consumption. They tested a Toyota Hilux 2.5 liters vehicle and found that using the right gear can save fuel. The researchers used data from the vehicle's onboard diagnostics to analyze engine speed, vehicle speed, and gear usage. They discovered that driving in fifth gear led to the lowest fuel consumption, with a 4.3% reduction compared to fourth gear. This shows that choosing the correct gear while driving can make a big difference in how much fuel a vehicle uses.