The Mazda 3 has been available with several engine options since it was first released in 2004. The company used similar design and construction with each model, varying primarily with size and intake. Mazda released the Mazda 3 with a turbo option in 2007 that calls for slightly different fluids. The fluid capacities vary by engine size. Consult your owner's manual for proper capacities for your specific engine size.
All variations of the Mazda 3 except for the turbo options call for SAE 5w20 engine oil. Mazda recommends using SAE 5w30 engine oil in the engines that come with turbo. Mazda recommends synthetic motor oils in all of their vehicles. You can also use a high-mileage or extended use engine oil for the older models or cars that are used for distance driving.
Mazda does not prohibit the use of additives in the engine oil. Several options include cleaners and oil boosters. Any additive that offers to recondition the seals of the engine will help to prolong the life of the engine. Additives tend to thicken motor oil, which may cause your engine to be sluggish when starting in cold weather.
Always check the other fluids when changing the oil. Mazda recommends synthetic multi-vehicle automatic transmission fluid for the automatic transmissions. Use SAE 75w90 manual transmission and transaxle gear oil for manual transmissions. Power steering fluid in the Mazda 3 calls for multi-vehicle ATF. Brakes and clutch use standard DOT-3 oil.