Modern engine oils come in a variety of viscosities, and it is more important than ever to choose the correct one. In this article, we will be discussing the differences between two of the more common viscosities, 10w30 and 5w30.
The numbers in the viscosity ratings represent how easily the oil pours or flows, the lower the number, the thinner the oil and the easier it flows. The first number represents how well the oil flows when cold, with the “W” meaning winter. And the second number indicates the flow when warm, such as inside an engine that is up to operating temperature. So, 5w30 would flow easier at a colder temperature than 10w30, but once warm they would flow the same.
Table of Contents
What Is The Similarity Between 5w30 And 10w30?
5w30 and 10w30 are similar in that they both have the same viscosity when warm. Both engine oils will have the same lubrication characteristics as long as the engine is up to operating temperature. They will both reduce the same amount of friction, aid in internal engine component cooling, and allow the oil pump to produce the same amount of oil pressure.
What Is The Difference Between 5w30 And 10w30?
The main difference between 5w30 and 10w30 is the cold temperature viscosity. 5w30 will flow easier when cold than 10w30. So during the warm-up period in the colder months, the engine’s oil pump will be able to move 5w30 easier than it could 10w30. Using 10w30 could cause a higher oil pressure when cold as opposed to 5w30, because the thicker oil will have to be at a higher pressure to move through the small oil passages inside your vehicle’s engine.
Which Oil Is Better: 5w30 Or 10w30?
While 10w30 and 5w30 have both differences and similarities, neither is particularly better than the other. 10w30 may offer slightly more engine protection than 5w30 in more severe duty applications, but the thinner 5w30 would also help lubricate internal components faster at startup. In a region with a colder climate, 5w30 may be the better choice, and in an area with a warmer climate, 10w30 could be a better choice.
Can I Use 10w30 Instead Of 5w30?
Most modern engines use something called variable valve lift and/or timing, and these are controlled by engine oil pressure. It is highly recommended that for these engines you use the proper engine oil viscosity, as the differences in oil pressure can have an effect on how these systems perform. In this case of 5w30 versus 10w30, the effects would probably not be very dramatic, but it is always best to follow the manufacturer’s recommendation on which oil to use.
In an older vehicle that doesn’t use these technologies, using 10w30 instead of 5w30 wouldn’t have much, if any, noticeable effects. Again, it’s best to stick to the manufacturer’s suggestion, but using 10w30 instead of 5w30, especially in a warmer climate or in a heavier duty application is fine.
Can You Mix 5w30 And 10w30?
Mixing engine oil viscosities is not recommended for long term use, but in a short term scenario, such as topping off a low oil level when there is no other option it would be OK. Having the oil changed and refilled with the proper motor oil should happen as soon as possible after mixing 5w30 and 10w30 to avoid potential engine damage.
Will 10w30 Hurt A 5w30 Engine?
In most cases, 10w30 will not hurt an engine designed for 5w30. 5w30 will offer easier engine starting in cold weather, but once warm there will be no discernible difference. As stated earlier, most modern engines use oil pressure to control different engine components. Using a non recommended engine oil weight could change oil pressure under different circumstances, thus causing these components to not operate as designed.
In older cars, 10w30 will likely not hurt or have any effect on a 5w30 engine. Once again, depending on your climate 10w30 might be a better choice. 10w30 could offer a little more protection in warmer weather or if under heavy load. So, take all of this into consideration while choosing an oil for your vehicle’s engine.
Read more: 5w30 Vs. 5w40: Which Oil Is Better?