04SilverGT

alright, i just changed my oil in my gt it takes 5w 20 right well i accidently put in 10w 30 will it hurt my motor or will i have to change it out i only started it up once, please reply with any thing that you know

4600cc

5W20 is for the winter. 10W30 is for the summer. You're good. Check oil level, and tell me that you did replace the filter with a good one.

jdaniel

Are you crazy? The 4.6 calls for 5W20 year round and thats what I have used year round for the past two years.

04SilverGT

I towed it to my dads shop and he i used the oil flusher just to make sure cause i didn't want any of it in there, and yes i did get a new oil filter when i changed it

dc_mann8

5 20? i use 10w30

4600cc

You're nuts then. 5W20 is winter oil. 20 refers to temerature rating for the break down of the oil, 5 is for the startup temerature rating. With 20 you will be hurting your motor when it's hot. 10W30 is good for the summer, some use 10W40 to get extra protection for the very hot weather.

I suggest you read this article twice, click here to read it.


[quote]Making Sense of Synthetic Lubricants

Don Stevens

Suncoast Region – PCA, BMWCCA, CVN



All of us have seen countless ads telling us to change our engine oil every 3000 miles. Some of us have watched the infomercials showing cars driving on the racetrack with allegedly no oil or engines running on a stand while the host pours sand and gravel over an exposed valve train. Virtually all of the lube shops have some kind of magic additive that they will say you need. What are we to believe? Or more relevant, what is right for you? In becoming an Amsoil Synthetic Lubricants dealer in 1998 I have done a great deal of research on all kinds of lubricants and additives and in this article I will share the facts about synthetic oils, petroleum based oils, and additives so that you can make an informed decision about what is right for your cars.



Oil Classifications.



There are two systems for oil classification. The SAE (Society of Automotive Engineers) viscosity grade and the API (American Petroleum Institute) classification that designates the type of engines for which the oil was designed. The SAE viscosity grade is known as the “W� number when classifying oils. Most oils on the shelf today are multi-viscosity such as 10W30 or 20W50. In general, the lower the first number, the better the oil will perform in extremely cold conditions. Conversely, the higher the second number the better the oil will protect at higher temperatures. If you were driving to Minnesota in the winter you would want the lowest number you could find like a 0W30. In our Florida climate however, a 10W40 or a 20W50 might be a better choice. Many newer cars require very light oils like 5W20 or 5W30. The new lighter weight oils are required for the manufacturer to meet CAFE fuel mileage standards. If you drive a late model car consult your owner’s manual to determine the recommended viscosity range that was intended for your car. The API designation is typically an “S� designation for gasoline engines and a “C� designation for diesel engines. Most of today’s oils carry an SH,CF or SJ,CF designation signifying that they are suitable for use in all gasoline or diesel automotive applications. There is a relatively new classification SL (July 2001) that most synthetics and synthetic blends meet but most petroleum oils do not. All the major oil companies are reformulating to meet the SL specs but it will take a while to deplete all of the SJ inventory. Those of you with diesel trucks or motor homes should look for an API CG-4 rated oil. Which brand you buy is largely a matter of preference. Consumer Reports (6/97) found very few differences between major brands of oil and all with the above SAE and API designations performed fine in normal applications.



Synthetic vs. Petroleum based oils.



Synthetic oils were originally developed more than 50 years ago and became widely used in jet engines. Less than -120ºF ambient temperatures, 60000 shaft rpm, and 500º+F exhaust temperatures proved too much for conventional oils. Synthetics were created specifically to withstand these harsh conditions and to date every jet engine in the world uses synthetic lubricants. Amsoil introduced the first synthetic oil for automotive use in 1972 and have continued to be at the leading edge of development ever since. Mobil-1, undoubtedly the most recognized name in synthetics, was introduced in 1976. Many companies have jumped on the bandwagon and have since released synthetic lubricants for automotive use and all are becoming increasingly popular for their superior lubricating properties, superior ability to flow at cold temperatures, and their ability to withstand high temperatures for extended periods of time. Several new cars including the Porsche 996 and the Chevrolet Corvette LT-1 are delivered with synthetic oil in the crankcase and require synthetic oil use throughout the life of the car.





There are two primary differences between synthetic oils and conventional petroleum oils. These are the base stock or liquid that makes up the volume of the oil, and the additive package. There are additives (not to be confused with over the counter additives which will be discussed later) in all oils that enhance the wear resistance properties of the oil, enhance the ability of the oil to neutralize acids and combustion by products, and provide corrosion protection for the engine’s internal surfaces. The amount and quality of these additives vary from one oil brand to another and this is a very significant factor in the ability of an oil to adequately protect your engine in all driving conditions. As a general rule of thumb, the cheaper the oil, the fewer additives it has and therefore, the less able it is to protect your engine.



There is one school of thought that suggests that the only difference in synthetic oils vs. petroleum oils is that the synthetics typically have a better additive package. This statement is only partially true. Synthetics almost always do have superior additives than petroleum oils. While this does add to the cost of the oil, it also enables the oil to last 3-5 times longer than conventional oil. The synthetic base stock however, is of paramount importance in the ability of a synthetic oil to flow at cold temperatures and withstand greater amounts of heat over significantly longer periods of time. Petroleum base stock molecules are long carbon chains that are sensitive to stress and heat. Additionally, various paraffins that are contained in all petroleum products regardless of how well refined they are, cause oil to jell like a syrup at extremely cold temperatures. At the other end of the temperature spectrum, high engine temperatures and heavy loads (as typically found in towing or racetrack applications) cause these chains to break down and the base stock actually boils off causing a change of viscosity and the formulation of sludge. This can happen at temperatures as low as 230º F and by 250º F many petroleum oils are suffering significant breakdown. Synthetic oils on the other hand are engineered specifically to provide all the lubricating properties that natural oil possesses, but none of the cold thickening or hot thinning properties of petroleum oil. Synthetics are made up of uniformly shaped molecules with shorter carbon chains which are much more resistant to heat and stress. Synthetics can withstand temperatures of 300ºF all day long and still protect your engine. In fact the American Society of Testing Materials (ASTM) standard wear resistance tests are conducted at 302º F. In this test synthetic lubricants far out perform petroleum lubricants by factor of four to one and greater.



Oil temperatures of 230ºF to 250ºF are not at all uncommon in driver’s education track conditions, particularly in early 911s with no front coolers or the marginally effective “trombone� oil coolers. These temperatures are also fairly common in air-cooled engines in summer time stop and go traffic with the A/C on. Further, temperatures on the cylinder walls and in turbos are often over 450°F for short periods of time. Liquid cooled cars can also have extremely high oil temperatures even though the w

jdaniel

Tell that to Ford when your engine dies and they find out that you wanst running 5W20 just like the owners manual and the oil cap says to use.

gt96stang

Nope. All I run is what the manual says. 5w20 year round it is and I havn't had no problems with what Ford recommends.

dc_mann8

they only recommend this for 4.6 isnt it

firemedix911

Ford recomends 5w20 motorcraft engine oil for it's 4.6's. That all you need to use. I don't like motorcraft though. I use royal purple syntetic.