Making separate short car trips is less efficient than combining them into one longer trip, as it takes more fuel to start and warm up the engine each time.
When planning a trip with several stops, e.g. errands around town, plan to drive the longest distance first to help get the engine warmed up. Your vehicle runs more efficiently at optimal temperature.
Also, choose routes and times to avoid traffic congestion, and get good directions if you're heading for an unfamiliar destination (getting lost wastes a lot of petrol.)
Even better, swop more of your short car trips for a walk or cycle.
(Olivia Rose-Innes, EnviroHealth Editor, Health24, August 2012)