Mazda’s RX-8 is the only production vehicle equipped with a rotary engine. Mazda has been using rotary engines since the 1960s, although their use in the past few decades has been limited to the RX-7, and more recently, the RX-8. The rotary engine is different from the piston engine most often found in vehicles. Its benefits include a high-power rating for its small size (the RX-8’s engine is only 1.3L, yet it produces 232-horsepower) and a higher RPM redline (the RX-8’s redline is 9000 RPM). Its disadvantages include a large thirst for fuel and oil consumption. Because of the RX-8’s engine design, special procedures must be followed to meet the engine-oil guidelines.
Mazda recommends using 5W-20 oil in your RX-8. The brand of your choice is acceptable, as long as the American Petroleum Institute certifies the oil. This oil will have a sticker proclaiming “Safe for Gasoline Engines” on the container. Mazda discourages the use of synthetic oil in the RX-8. According to Automotive News, RX-8 engines using synthetic oil are prone to failure.
The RX-8’s Renesis rotary engine consumes oil at an accelerated pace, compared to a traditional-piston engine. For this reason, Mazda recommends checking the oil level in your RX-8 every other fuel-fill up, and adding when necessary. If the RX-8 is driven aggressively, check the level more often; it’s likely to consume more oil. The diminutive-rotary engine only holds 3.5-quarts of oil; for comparison, the Mazda 3 sedan’s capacity is 4.3-quarts. A smaller capacity means it takes less oil burn off to reduce the oil to a dangerous level. The difference between the “L” and “F” mark on the indicator is 1.7-quarts; use this as a guide when adding engine oil.
Mazda recommends keeping a couple quarts of oil and a funnel handy for adding oil. It’s also important not to overfill the engine with oil; this can also cause damage.
Mazda’s recommended interval for engine oil and filter changes depend on your climate and driving conditions. Schedule two is for driving conditions that include frequent stop-and-go driving, rough or muddy roads, dusty conditions, excessive brake use or extremely cold or humid climates. If these conditions apply, the engine oil and filter require replacement every 3,000-miles or three months, whichever comes first. If these conditions do not apply, the oil and filter should be replaced every 7,500-miles or six months.