What if you put 5w-30w oil instead of 5w-20w oil in your engine?

Using 5W-30 oil instead of 5W-20 oil in your engine can lead to decreased fuel efficiency and potentially affect engine performance. The thicker viscosity of 5W-30 may not provide optimal lubrication at operating temperatures, which can increase wear on engine components. While it may not cause immediate damage, consistently using the wrong oil could shorten the engine's lifespan. It's best to stick to the manufacturer's recommended oil for optimal performance and longevity.