you will get to know what gear your vehicle likes. if the engine labours change down. with my vehicle 95 clicks is in perfect conditions. eg. no head winds. bad conditions I would leave it in 3rd and drive between 90 and 95 k's. steep mountain ranges climbing I would change gears down early keeping turbo spooling with tacho around 2800 to 3000rpm. your patrol will be different than mine as gear ratio and engine are not the same.