Is Mixing 5W-20 and 5W-30 Engine Oil Safe?

Learn why mixing 5W-20 and 5W-30 engine oils can affect performance and warranties.

Published Jul 14, 2025

Overview

In today's video, we tackle a common question among car owners: Can you mix 5W-20 engine oil with 5W-30? Understanding the viscosity ratings and their implications for engine performance are essential for maintaining your vehicle. This informative Q&A sheds light on why mixing these oils is generally discouraged, highlighting the importance of adhering to manufacturer specifications for optimal engine health and longevity.

Video transcript

Mixing 5W-20 with 5W-30 is generally not recommended as it can compromise your engine's performance and void warranties. While both oils have similar cold-start viscosities (5W), their operating temperatures differ (20 vs 30). Using the manufacturer-recommended oil ensures optimal engine protection and efficiency.

Questions and answers

What happens if I mix 5W-20 and 5W-30 oil?
Mixing 5W-20 with 5W-30 can compromise engine performance and potentially void your warranty since the oils have different operating temperature viscosities.
Is it safe to use different engine oils?
It is generally not recommended to mix different engine oils unless specified by the manufacturer, as this may affect lubrication and engine function.
How do I choose the right engine oil for my vehicle?
Always refer to your vehicle's owner manual for the recommended oil viscosity and specifications to ensure optimal performance and protection.
What is the difference between 5W-20 and 5W-30 oil?
The main difference is their operating temperature range; 5W-20 is thinner at high temperatures compared to 5W-30, affecting engine performance depending on the conditions.