Check your tire pressure at least once a month. Under-inflated tires burn more fuel. If tires are 8 pounds (3.6Kgs) under inflated, (not an uncommon condition), rolling resistance of the tires increases by 5 per cent.
Don’t let the vehicle idle for more than a minute. Idling consumes half-a-gallon(1.9Ltrs) to one gallon (3.8Ltrs) of gas per hour and pumps needless CO2 into the atmosphere. The modern engine will consume less fuel turning off and re-starting than idling for extended periods.
Also, to effectively warm an engine, drive it, don’t rev it. Engines only work hard under load and will warm up much quicker if you simply start the engine, wait for 20 seconds, (this builds the oil pressure,) and drive away.