fuel-viscosity variation

例句：

1. 1. The engine's performance is affected by the fuel viscosity variation.
   发动机的性能受到燃料粘度变化的影响。
2. 2. Engineers need to monitor the fuel viscosity variation to ensure optimal performance.
   工程师需要监测燃料粘度变化，以确保最佳性能。
3. 3. The fuel viscosity variation affects the efficiency of the engine.
   燃料粘度变化影响发动机的效率。