oil viscosity oil temperature ranges e carFirst and foremost look at your car’s manual. The car manufacturers will specify the correct oil for your car. You can purchase this oil from your local midas, game, autozone or local workshop. e-CAR has qualified mechanics. The will be able to advise you on the best oil for your car.

So let us tell you a little about the oil that goes into your car.

The difference between 5W30 vs 10W30 car oil

The W in the middle of the numbers stands for “Winter”



Thinner at lower temperatures. Thicker at lower temperatures.
Lower Viscosity Higher viscosity
Works within the temperature range of -30 degrees Celsius to 35 degrees Celsius. Works within the temperature range of -18 degrees Celsius to 30 degrees Celsius.
Used by light duty petrol and diesel engines. Used by heavy load hauling engines.
Provides better cold weather starting. Provides better sealing action.
How fast the oil flows during engine start-up. The lower the number, the faster it flows. How well your oil protects your engine at high temperatures. The larger the number, the greater the protection.

Below is a table of more variations of motor oil grades.


As you can see from the chart above the first number is the low temperature range and the second number is the high temperature range. The higher the number after the W means it can handle higher temperatures. So the next question is how hot does an engine get?

For most cars, the normal operating engine temperature is in a range of 90 -950 Celsius, but most dashboard temperature gauges don’t show an exact teperature. As the temperature increases the radiator fan will kick in to start cooling the engine. To put it into perspective when you boil your kettle. The boiling point is (not to get too technical) about 1000 C. If your car overheats or you need to top up with water and you have been driving your vehicle do not open the radiator or expansion bottle cap as the water will be hot and will burn you. Wait for the water in the radiator to cool down before filling up with cold or normal temperature water.

SAE 30, 40 or 50 is monograde oil. This oil is no longer used in the latest car engines, but may still be used in some vintage and antique engines. SAE 30 is often used in small air-cooled engines in lawnmowers, garden tractors, chain saws and portable generators.


Do not over fill your engine with oil.