机油黏度等级详解
SAE 标号如 5W-30 含两个数字。W 前的数字表示低温泵送性能，W 后的数字表示高温时的黏度。请按汽车厂家针对你所在气候的建议选择标号。
| 标号 | 低温(W) | 高温黏度 | 典型用途/气候 |
|---|---|---|---|
| 0W-16 | W = winter; flows at very low temp | Very low hot viscosity | Hybrid/modern engines; best fuel economy, mild climates |
| 0W-20 | Winter rating, pumps cold to -40C class | Low hot viscosity | Newer petrol engines; cold climates, fuel saving |
| 5W-20 | Winter grade, good cold flow | Low hot viscosity | Many US/JP petrol engines; moderate climates |
| 5W-30 | Common winter grade | Medium hot viscosity | Most modern petrol/diesel; wide climate range |
| 0W-30 | Winter grade, very cold flow | Medium hot viscosity | Cold regions; long-drain modern engines |
| 5W-40 | Winter grade, broad use | Higher hot viscosity | Turbo petrol/diesel; hot climates, towing |
| 10W-30 | Pumps at moderately cold temp | Medium hot viscosity | Older engines; temperate climates |
| 10W-40 | Standard winter grade | Higher hot viscosity | Older/high-mileage engines; warmer areas |
| 15W-40 | Needs warmer start | High hot viscosity | Diesel, trucks, older engines; hot climates |
| 20W-50 | Thick, warm-start only | Very high hot viscosity | High-temp, heavy load, older V8; hot climates |
说明
- 务必以车辆手册为准；机油过稠会影响油耗与冷启动。
- 合成油比矿物油在宽温范围内更稳定保持等级。
常见问题
- 5W-30 里的 W 是什么意思？
- W 代表冬季（winter）；前面的数字（5）表示机油在低温下的泵送等级，于低温测试。
- 哪个数字是高温黏度？
- W 后的数字（30）是高温黏度等级，在 100°C 下测定。
- 可以用比推荐更稠的油吗？
- 不建议。过稠会降低油耗表现且冷启动流动差，请遵循厂家规格。
- 0W-20 比 5W-30 更好吗？
- 没有绝对更好；0W-20 低温流动性好、省油，但只可用发动机允许的标号。