The Mini Cooper, a subset of BMW, offers the 2005 model with two engine options that are the same size but different capacities. The engines are signified by a code--W10 and W11--that is printed on a sticker on the underside of your hood or inside your owner's manual. The proper fluid levels are identified through this code.
Both variations of the engine call for synthetic SAE 5w30 engine oil. The engine code W10 uses 4.8 qts. with a new filter change, and the code W11 uses 5.1 qts. Oil additives are not prohibited by the manufacturer. Higher-mileage engines or distance driving calls for the use of an oil additive that reconditions the engine oil seals. Always subtract the amount of additive you add to the oil from the amount of oil the engine requires. Add the additive first.
Both models use a MANN Oil Filter (HU8162x) or other manufacturer's equivalent. The oil filter is an internal filter within an aluminium housing located near the firewall on the passenger side. The housing cap is removed using a large hex head wrench. Always replace the rubber gasket ring around the cap with a new one included with a filter purchase. Lubricate the new gasket ring with fresh oil to avoid damaging the gasket during installation.
The power steering system calls for standard power steering fluid. The clutch and brake system requires DOT-4 brake fluids. Do not overfill any of the systems as you could damage internal seals. Consult your owner's manual or dealer for fluid type options for the transmission.