Engine oils are categorized by their level of viscosity.
The viscosity of an engine oil is also known as the thickness of the oil and is a property that determines how well it can flow through the engine in various conditions.
The higher the viscosity, the thicker the oil will be.
To create clear differences between the different oil types and their viscosity rating, the (SAE) Society of Automotive Engineers assigned different codes to the oils such that the higher the number, the thicker the oil will be in context.
However, given that engine oils malfunction in both hot and cold weather conditions, the assignation of the codes is in two parts separated by a letter “W”.“W” stands for the cold viscosity of the oil, the number that comes before it is the cold viscosity rating of the oil, while the one that comes after it is the hot viscosity rating.
As explained earlier, the higher the rating, the thicker the oil will be in each context.
Generally, thick liquids have honey-like consistency and are assigned high viscosity values while thin liquids have more of a water-like feel to them and as such are assigned lower viscosity values in comparison.
Interestingly, both high and low viscosity ratings have their pros and cons and your choice would have to be made based on the cons your current environment can handle.
For example, thinner oils tend to improve the gas mileage of your vehicle. However, under hot temperature, they lose their quality and with it their ability to lubricate your engine properly. This then leads to wear and tear.
Thicker oils on the other hand thrive in very hot conditions and are very helpful in plugging leaks in old engines, but in cold conditions, they aren’t very functional and your engine will have a hard time starting up.
5w30 vs 10w30 – Their Similarities
Given that engine oils are differentiated by their viscosity ratings in different contexts, both types under consideration are similar in terms of their hot viscosity rating of 30.
This is the most common hot viscosity rating because it is the most compatible with hot environments. What this means is that even in hot climate conditions, both oils do not get so thin that they lose their ability to lubricate the engine properly.
5w30 vs 10w30 – Their Differences
Obviously, the cold viscosity rating is the difference between 5w30 vs 10w30. However, as explained earlier, the higher the number, the thicker the oil will be in a particular context. This means that between the two in comparison, the 10W30 is the most viscous in cold weather conditions.
Similarly to the explanation about hot viscosity, this implies that 10W30 tends to be thicker in cold climates but then again, we don’t need the engine oil to be too solid in cold climates because then, they can’t even flow through the engine at all.
For example, if your house doesn’t have an indoor garage and it snows overnight, the overall temperature of the vehicle will be altered and most of the liquids in the engine could become frozen.
If your car uses an engine that’s already thick and this happens, there’s no way you’re driving that car anytime soon. Therefore, 10W30 is more suited to hot climates where the viscosity can only be reduced and still be good enough to power your vehicle given its temperature range is from -18 degrees Celsius to 30 degrees Celsius.
5W30 on the other hand has a decent cold viscosity rating nicely complemented by a commendable hot viscosity rating. With such thickness, the viscosity of the oil is not so affected by cold weather that it ceases to flow and lubricate the engine.
It has an operational temperature range of -22 degrees Celsius to 35 degrees Celsius which is a lot more than that of the 10W30. This means that it is very adaptable in cold areas such as Canada and even hot areas such as Los Angeles in the United States.
Which of them is best for your car?
In this table below , we list the top 3 5W30 and 10W30 oils.
|Synthetic Oil||Oil Type||Check Price|
|1). Mobil 1 120770||10W30|
|2). Pennzoil 550046205||10W30|
|3). Valvoline Full Synthetic Motor Oil||10W30|
|1). Mobil 1 (120766)||5W30|
|2). Castrol 03087||5W30|
|3). Valvoline 782256||5W30|
According to Tom and Ray Magliozzi of the NPR car talk, it is recommended that if you stay in areas with decent temperature ranges, it probably won’t make a difference which engine oil you choose. However, you can never be faulted for going with your manufacturer’s recommendation.