Which engine oil is better, 5w40 or 10W40?

5w40 is better for starting your engine at low temperatures as it flows more easily at these temperatures. When the engine is running and hot, 5w40 and 10w40 have high viscosities and are equally effective in protecting against engine wear.

Is it bad to mix 5w40 with 10W40?

The only reason not to mix them is because they may have different additives that have different benefits. When you mix them your bringing both down to the lowest common denominator as far as performance goes. What this means in reality is you should change your oil a little sooner.

Can I use 5w40 instead of 10W40 on Reddit?

5w40 is effectively the same thing once it's at operating temperature, so you'll be fine to run that.

Which is better, 5w30 or 10W40?

In other words, a lubricant with SAE 5W-30 will behave better when cold than a lubricant with SAE 10W-40. In contrast, oils with a higher SAE after the W generate thicker films of lubricant and better protect the mechanical parts when the vehicle is already hot.

No, you can use 5w-40 anywhere a 10w-40 is recommended. At operating temperatures, both oils are 40wt and are equivalent. What matters most is the operating temp viscosity (the 2nd number). The first number ( …
Наприклад, 5w40, 10w40, 15w 40;; літні – мають один показник, який вказує на максимальну густоту. Чим вище цей показник, тим краще. Наприклад, 0w, 5w, 20w, 30w …
Personally, I wouldn’t run a 5w if it calls for a 10w. It might give you slightly better lubrication in the engine during cold temps, but, might impact the performance of your transmission in a negative way.