The Smart car, officially known as the Smart Fortwo, is a dynamic mini-car with a diminutive 1.0-litre three-cylinder engine. Changing the oil in a Smart Fortwo is easier than in most vehicles; the unique engine location allows you to change the oil without lifting or crawling far underneath the vehicle. The Fortwo comes from the factory with synthetic oil; the recommended service interval is 10,000 miles.
Drive the Smart Fortwo at normal speeds for about 10 minutes to warm up the engine oil. Turn the engine off, set the parking brake and gather the tools and supplies. Refer to your factory maintenance booklet to determine the correct oil grade and viscosity (it varies depending on climate).
Place an oil drain pan underneath the oil drain plug. Since the Fortwo has a rear engine, the drain plug is on the rear underside of the vehicle on the passenger's side.
Remove the oil drain plug with the socket spanner and let the oil drain for 20 to 30 minutes until the drips are 5 to 10 seconds apart.
Remove the oil filter. Use an adjustable filter spanner unless you have a spanner specifically designed for the Smart Fortwo. Set the oil filter in the drain pan when you remove it.
Prepare and install the new oil filter. Coat the tip of the filter with a thin layer of oil and then tighten it by hand. Do not use a filter spanner to tighten the oil filter; this risks overtightening.
Replace the oil drain plug. Tighten it well with the socket spanner.
Open the cargo compartment of the Fortwo to access the engine. Remove the black cap and add 3 1/2 litres (118 fl oz) of oil using a standard funnel. Replace the cap.
Start the engine and let it run for a few minutes. Turn the engine off and check the oil level using the dipstick in the engine compartment. The level should not be over "F"; if it is, drain enough oil to bring it to the correct level.
Dispose of the used engine oil and filter. Bring the drain pan to a service station or a dealer's service department to properly dispose of the oil.
Contact your nearest Smart dealer to obtain the correct oil filter. You can also check with an car parts stockist to determine whether there's an aftermarket equivalent.