Make sure your engine is cooled completely before you begin.

Pour Gunk Engine Flush into the crankcase (where you pour your oil in). This flush will help remove gum, varnish, and sludge from the engine compartment.

Run the vehicle at idle for 5 minutes. Do not drive the vehicle with the Gunk Engine Flush in.

Loosen the drain plug.

Put the drain pan under the drain plug.

Once all the oil has drained, place your new Sure Drain plug into the oil pan and twist on the protective dust cap. The next time you change your oil, you won't have to remove the drain plug; you'll only have to attach a drain hose. How's that for simple?

If you're using the old drain plug, remember to install a new drain plug gasket. This will prevent leaks.

Now put the drain pan under the oil filter.

Remove the oil filter with your oil filter wrench.

Install the new oil filter, tightening according to your cars specifications. Talk to a Parts Pro for these.

Fill the crankcase with new oil and pat yourself on the back. You're done!

Oil lubricates the engine and assist in cooling. The steady flow of oil through the engine carries away a great deal of the heat that is generated.

Oil seals. Piston rings will not function properly without oil as a sealing agent.

Oil will clean. Detergents in the oil help remove engine sludge, carbon and more.

Oil viscosity is the measure of oil's ability to resist flowing. The Society of Automotive Engineers (SAE) has set low and high temperature requirements for oil.

Low = 0 degrees Fahrenheit or –18 degrees Celsius
High = 210 degrees Fahrenheit or 99 degrees Celsius

Oils that meet the SAE low temperature requirements have the letter W (stands for winter, not weight) following the viscosity rating (SAE 10w).

Oils that meet the high temperature requirements don't have the "w" after the SAE 30.

Oils thin out when heated and thicken when cooled. A good engine oil must be thin for cold starts and thick enough at high temperatures.

This is where multi-grade oils come into play.

The weights given on oils are arbitrary numbers assigned by the SAE. These numbers correspond to "real" viscosity, as measured by several accepted techniques. These measurements are taken at specific temperatures.

Oils that fall into a certain range are designated 5, 10, 20, 30, 40, 50.

The "w" means the oil meets specifications for viscosity at various low temperatures depending on weight, and is therefore suitable for Winter use.

5W is tested at -25C
10W at -20C
15W at -15C
20W at -10C

Use the chart below to familiarize yourself with the chemical and physical properties of conventional motor oil:

Multi-grade oils work like this: Polymers are added to a light base (5W, 10W, 20W), which prevent the oil from thinning as much as it warms up.

At cold temperatures the polymers are coiled up and allow the oil to flow as their low numbers indicate. As the oil warms up the polymers begin to unwind into long chains that prevent the oil from thinning as much as it normally would.

The result: at 100 degrees Celsius the oil has thinned only as much as the higher viscosity number indicates.

Another way of looking at multi-grade oils is to think of a 10W-30 as 10 weight oil that will not thin more than a 30 weight would when hot.

Synthetic motor oil, when compared to conventional motor oils, offer pretty serious performance benefits:

• Superior protection in low temperatures, enabling easier and faster start-ups in cold weather (as low as -40°F)
• Enhanced high-temperature durability, reducing oxidation and wear on critical engine parts (up to 400°F)
• Reduced oil consumption under high-speed conditions
• Superior performance under heavy engine loads/stresses, such as hauling and towing
• Increased stability and better control of deposits that can impede flow and lead to higher wear

If you work your engine hard, drive in extreme heat, or have cold weather starts, then synthetic oil will protect your engine better.