SAE is a numerical code system established by The Society of Automotive Engineers (SAE). This code is used for grading different motor oils or engine oils according to their viscosity. 

As oil viscosity changes with the temperature, multigrade oils are produced to deliver protection across a variety of different temperatures. This is why the labels of oil bottles show codes like “SAE 30” or “5W-30”, in order to expose the viscosity characteristics of the oil.

Now, you must be wondering how this code actually expresses the characteristics of an oil. For better understanding, let’s consider a 5W-30 oil. Here the number before “W” stands for the viscosity of the oil at a low temperature. The lower number you see, the thinner is the oil. The thinner the oil is, the better its performance in a cold temperature.

The number after W stands for the thickness of the oil at a normal operating temperature. Thus, the SAE code helps to understand the density of the oil and guess its performance in different weather conditions.

What is a SAE 30 Engine Oil?

What is SAE 30 Engine Oil

SAE 30 oils are single grade oils that have viscosity ratings of 30. To be more precise, these oils show a viscosity rating of 30 when they are in a 100 degrees celsius temperature. 

SAE 30 oils are known as single grade or mono-grade oils because they have only one viscosity grade. Thus it shows different characteristics when compared to a multi grade oil like 5W-30, rated for both 5W and SAE 30.

Single grade oils like SAE 30 can only be rated for a hot or cold-start viscosity grade. In case of a cold-start viscosity grade, it shows a “W” as a suffix, which actually stands for “Winter”. In a multi grade oil on the other hand, winter grade viscosity emulates engine crank at a low temperature.

SAE 30 oils are rated for hot viscosity only. This rating states how viscous the oil is, at an operating temperature of 100 degree celsius.

What is SAE 30 Motor Oil Used for?

SAE 30 oils are mainly used for small air-cooled engines. They are widely used in small sized tractors, lawn mowers, and chain-saws. However, they are rarely used in advanced and modern vehicles. Most modern vehicles today use motor oils that perform dexterously regardless of the season.

What Is 5W-30 Engine Oil? 

What is 5w30 Engine Oil

5W-30 engine oils are multi grade oils which range from a lower viscosity of 5 to a higher viscosity of 30. The number preceding “W” here stands for its viscosity or thickness at lower temperature conditions, and the number after W stands for its viscosity or thickness at higher temperature conditions, particularly at the time the engine is running.

Just like most of the other motor oils we can find in the market today, 5W-30 is a multi grade oil. Having a lower viscosity of 5 and a higher viscosity of 30, they can show great performance in different weather conditions. These oils are thin enough to flow effortlessly at a lower temperature, and thick enough to work perfectly in high temperature conditions. 

What is a 5W30 Motor Oil used for?

Due to the high adaptability in a diverse range of weather conditions, 5W-30 oils are highly used in engines requiring light duty petrol and diesel. They are suitable for a number of different vehicle types. Considering its brilliant performance in lubricating, sealing, and protecting the internal components of an engine, automakers highly recommend using them in passenger cars, light vans, SUVs, and trucks.

See how 0w40 vs 5w30 Engine Oil Compare.

SAE 30 vs 5w30 Engine Oil Differences

If you demand good performance from your car regardless of the weather condition, there is no better way than to go for a multi-viscosity motor oil. However, SAE 30 oils are single viscosity oils and they are not capable of delivering a smooth performance regardless of the weather.  

In a 5W30 oil, 5W refers to the fact that this oil will act like a 5 weight thinner oil at a cold temperature. When it gets hot instead, it is supposed to act like a thick 30 weight oil. A 30 weight engine oil at 300° Fahrenheit being much thicker than a 5 weight engine oil at the same temperature, can provide a much better performance in a diverse weather conditions.

Such characteristics of a multigrade oil not only make the car suitable for running smoothly in different weather conditions but also prolongs engine life by keeping it in good health.

On the other hand, SAE 30 oils are single grade oils and they are not capable of providing a satisfactory performance in extreme weather conditions. At a cold temperature, these oils generally take a long time before starting to flow. 

In order to draw a better illustration of the differences between a SAE 30 and 5W30, a table of comparison between the two oils has been provided here:

Table of Comparison between SAE 30 & 5W30 Engine Oil

Comparison ParametersSAE 30 Motor Oil5W30 Motor Oil
GradeSingle grade Multi grade
Viscosity Higher Higher
Thickness at Lower TemperatureThicker Thinner
Appropriate forGeneral weather conditionsBoth general and extreme weather conditions
Best to Use forSmall tractors, lawn mowers, and chain-sawsPassenger cars, light vans, SUVs, trucks.

A single grade oil like SAE 30 cannot compete with a multi grade oil like 5W30 in diverse weather conditions. Modern cars demand oils with the most powerful and diverse characteristics, and this is why a SAE 30 oil should not be used in place of a 5W30 oil.


Can I use SAE 30 instead of 5w30 in my car?

While multi-grade oils like 5W30 oils can provide an excellent performance in different weather conditions, single grade oils like SAE 30 show a deteriorated performance in extreme weather conditions. You might find some old classic cars that specify to use SAE 30 oil for its engine, but modern cars require multi-grade oils to complement itself. This is why it is inadvisable to use SAE 30 oil in a modern car instead of a 5W30 oil.

Can I mix SAE 30 with 5w30?

SAE 30 oils are single grade motor oil, while 5W30 oils are multi grade motor oil. 5W30 oils provide an excellent performance regardless of the weather condition, but SAE 30 oils are not appropriate for extreme weather conditions. If you mix the two oils together, the powerful and diverse characteristics of the 5W30 oil will decline, and so it will not translate into a good perform

The Final Verdict

Single grade oils like SAE 30 cannot provide a strong and powerful performance in extreme weather conditions, and this is the major reason why multi grade oils have been made. Multi grade oils can help your car to deliver a smooth performance regardless of the weather condition, which makes it suitable for cars that need to cover a long distance.

You need to remember, modern cars are not only advanced but also complicated. They demand only the most strong and powerful oils to deliver you the top-of-the-class performance you desire. If you need such excellent performance, you need to keep the SAE oils aside and feed your car with healthy and energetic 5W30 oils!