Can Motorcycles Use Car Engine Oil?
2 Answers
Motorcycles should not use car engine oil. There are two key points to note when selecting motorcycle lubricating oil: 1. Grade: Currently, SE, SF, SG, and SJ grades are available in the market, with the latter being higher. Generally, SF or SG grade oil is sufficient for normal riding needs. For frequent high-speed riding, it's recommended to use a higher grade, with SG being the minimum. However, note that even with high-grade oil, it should be changed every 1000~2000KM. Don't believe claims that oil can last 10,000 kilometers without changing—any oil will severely degrade after 500 to 1000 kilometers in an engine environment exceeding 1000°C, losing its lubricating effectiveness. 2. Viscosity. Multi-grade oils (labeled as 10W-30 or 15W-40, etc.) can be used year-round, with viscosity suitable for different temperatures in winter and summer. Single-grade oils like SAE40 are only suitable for summer use and can be safely chosen for vehicles with significant engine wear. Using high-viscosity oil indiscriminately in general vehicles can lead to poor oil circulation, machine damage, irreversible consequences, and in severe cases, cylinder scuffing.
I've been riding motorcycles for over a decade and have considerable experience with engine oil. The structure of motorcycles is completely different from cars—motorcycle engines and gearboxes share the same oil reservoir, so the oil must lubricate both the engine and the transmission system. Car engine oils often contain friction-reducing additives to improve fuel efficiency, which works well for car engines but is disastrous for motorcycles—it can cause clutch slippage, especially noticeable when climbing hills or accelerating, as if the power is being eaten away. My neighbor once tried to save money by using car engine oil, and within three months, the clutch plates were severely worn out, with repair costs enough to buy ten bottles of specialized oil. Motorcycles generally operate at much higher RPMs than cars, and regular car engine oil tends to thin out at high temperatures, significantly reducing its protective effect. So, I genuinely advise not to skimp on this small expense—specialized motorcycle oil may be more expensive, but it's worth it.
