The reason for that is the way viscosity works. 10w30 and 10w40 motor oils both have very different viscosities, which means that it is difficult for them to mix. Higher temperature oil (10w40) does not mix well with lower temperature oil (10w30) and eventually separates into its own layers once your engine starts operating again. 10w30 &10w40: What do they Mean? Low temperature viscosity; High Temperature viscosity; Difference Between 10w30 & 10w40 Engine Oil. Fuel Economy; Suitable Weather; High Mileage Engines; Motorcycle Use; Price Difference; Application; FAQ . Can you use 10W-40 instead of 10w30? Which oil is thicker, 10w-40 or 10w-30? Can I mix 10w30 with 10w40 The main difference between 10W30 and 10W40 oil is their viscosity. 10W30 oil is a type of motor oil that has a lower viscosity. This means that it is thinner and flows more easily than 10W40 oil. 10W30 oil is typically used in warmer climates or during the summer months. 10W40 oil is a type of motor oil that has a higher viscosity. Sempre bato muito na tecla sobre as viscosidades de óleo de motor, o quão importante é que você fique atento ao óleo que deve ser utilizado na sua moto. O ma Posted April 29, 2021. 6 hours ago, jochuma3 said: I have been told by a buddy that works in the industry that Motul and Motorex are literally the exact same oil under different branding. He said the both are process in the exact same place and then get packaged under the different names. F3SOy0f.

motul 10w30 vs 10w40