[oldernewbie]

My '06 came with 5w/20 syn/blend when I drove it off the lot. I've had 2 oil changes since (both at the dealership for record purposes) and I asked the tech what brand he recommends for a do-it-yourselfer. He said to use Castrol Syntec. I know thats his oppinion, but like buttholes, everybodys' got one.

[2k05gt]

Synthetic motor oils have been the object of numerous misconceptions held by the general public. Many people, including some mechanics, have been misled by these persistent myths.

Synthetic motor oils are fuel efficient, extended life lubricants manufactured from select base stocks and special purpose additives. Synthetic oil base stocks are made from organic compounds or synthetic hydrocarbons using a process that re-arranges the structure so all the molecules are uniform in size, shape and weight, a phenomenon that does not occur in nature. In contrast to petroleum oils which are pumped from the earth and refined, synthetics are custom-designed to produce, in effect, the ideal lubricant.

In responding to the objections most commonly raised against synthetics it is important to establish the parameters of the debate. When speaking of synthetic motor oils, this article is defending the lubricants which have been formulated to meet the performance standards set by the American Petroleum Institute (API). (The first such synthetic motor oil independently tested and confirmed to meet these industry-accepted tests for defining engine oil properties and performance characteristics was AMSOIL 100% Synthetic 10W-40 in 1972.)

Many people with questions about synthetics haven't known where to turn to get correct information. Is it super oil or snake oil? Some enthusiasts will swear that synthetics are capable of raising your car from the dead. On the other hand, the next fellow asserts that synthetics will send your beloved car to an early grave. Where's the truth in all this?

In an effort to set the record straight, I've assembled here a few of the more persistent myths about synthetic motor oils to see how they stack up against the facts.

Synthetic oils are too thin to stay in the engine.
Untrue. In order for a lubricant to be classified in any SAE grade (10W-30, 10W-40, etc.) it has to meet certain guidelines with regard to viscosity ("thickness").

For example, it makes no difference whether it's 10W-40 petroleum or 10W-40 synthetic, at -25 degrees centigrade (-13F) and 100 degrees centigrade (212 degrees F) the oil has to maintain a standardized viscosity or it can't be rated a 10W-40.

Synthetic motor oils damage seals.
Untrue. It would be foolhardy for lubricant manufacturers to build a product that is incompatible with seals. The composition of seals presents problems that both petroleum oils and synthetics must overcome. Made from elastomers, seals are inherently difficult to standardize.

Ultimately it is the additive mix in oil that counts. Additives to control seal swell, shrinkage and hardening are required, whether it be a synthetic or petroleum product that is being produced.

Synthetic oils cause cars to use more oil.
Untrue. Synthetic motor oils are intended for use in mechanically sound engines, that is, engines that don't leak. In such engines, oil consumption will actually be reduced. First, because of the lower volatility of synlubes. Second, because of the better sealing characteristics between piston rings and cylinder walls. And finally, because of the superior oxidation stability (i.e. resistance of synthetics against reacting with oxygen at high temperatures.)

Synthetic lubricants are not compatible with petroleum.
Untrue. The synthesized hydrocarbons, polyalphaolefins, diesters and other materials that form the base stocks of high-quality name brand synthetics are fully compatible with petroleum oils. In the old days, some companies used ingredients that were not compatible, causing quality synlubes to suffer a bum rap. Fortunately, those days are long gone.

Compatibility is something to keep in mind, however, whether using petroleum oils or synthetics. It is usually best to use the same oil for topping off that you have been running in the engine. That is, it is preferable to not mix your oils, even if it is Valvoline or Quaker State you are using. The reason is this: the functions of additives blended for specific characteristics can be offset when oils with different additive packages are put together. For optimal performance, it is better to use the same oil throughout.

Synthetic lubricants produce sludge.
Untrue. In point of fact, synthetic motor oils are more sludge resistant than their petroleum counterparts, resisting the effects of high temperature and oxidation. In the presence of high temperatures, two things can happen. First, an oil's lighter ingredients boil off, making the oil thicker. Second, many of the complex chemicals found naturally in petroleum base stocks begin to react with each other, forming sludge, gum and varnish. One result is a loss of fluidity at low temperatures, slowing the timely flow of oil to the engine for vital component protection.

Further negative effects of thickened oil include the restriction of oil flow into critical areas, greater wear and loss of fuel economy.

Because of their higher flash points, and their ability to withstand evaporation loss and oxidation, synthetics are much more resistant to sludge development.

Two other causes of sludge -- ingested dirt and water dilution -- can be a problem in any kind of oil, whether petroleum or synthetic. These are problems with the air filtration system and the cooling system respectively, not the oil.

Synthetic oil can't be used with catalytic converters or oxygen sensors.
Untrue. There is no difference between synthetic and petroleum oils in regards to these components. Both synthetic and petroleum motor oils are similar compounds and neither is damaging to catalytic converters or oxygen sensors. In fact, because engines tend to run cleaner with synthetics, sensors and emission control systems run more efficiently and with less contamination.

Synthetic oils void warranties.
Untrue. Major engine manufacturers specifically recommend the use of synthetic lubricants. In point of fact, increasing numbers of high performance cars are arriving on showroom floors with synthetic motor oils as factory fill.

New vehicle warranties are based upon the use of oils meeting specific API Service Classifications (for example, SJ/CF). Synthetic lubricants which meet current API Service requirements are perfectly suited for use in any vehicle without affecting the validity of the new car warranty.

In point of fact, in the twenty-eight years that AMSOIL Synthetic Lubricants have been used in extended service situations, over billions of miles of actual driving, these oils have not been faulted once for voiding an automaker's warranty.

Synthetic oils last forever.
Untrue. Although some experts feel that synthetic base stocks themselves can be used forever, it is well known that eventually the additives will falter and cause the oil to require changing. Moisture, fuel dillution, and the by-products of combustion (acids and soot) tend to use up additives in an oil, allowing degradation to occur.

However, by "topping off", additives can be replenished. Through good filtration and periodic oil analysis, synthetic engine oils protect an engine for lengths of time far beyond the capability of non-synthetics.

Synthetic oils are too expensive.
Untrue. Tests and experience have proven that synthetics can greatly extend drain intervals, provide better fuel economy, reduce engine wear and enable vehicles to operate with greater reliability. This more than offsets initial price differences. All these elements combine to make synthetic engine oils more economical than conventional non-synthetics.

In Europe, synthetics have enjoyed increasing acceptance as car buyers look first to performance and long term value rather than initial price. As more sophisticated technology places greater demands on today's motor oils, we will no doubt see an increasing re-evaluation of oil buying habits in this country as well.

Since their inception, manufacturers of synthetic motor oils have sought to educate the public about the facts regarding synthetics, and the need for consumers to make their lubrication purchasing decisions based on quality rather than price. As was the case with microwave ovens or electric lights, a highly technological improvement must often overcome a fair amount of public skepticism and consumer inertia before it is embraced by the general population.

The 3000 mile motor oil change is nothing but a myth and a money generating plan which virtually guarantees your vehicle's engine and powertrain will wear out at an early age when using any petroleum based motor oil. This is precisely what they want! That way you have to buy a new vehicle often.

Some Reading material
http://www.bobistheoilguy.com/

http://www.royalpurple.com/

http://www.calsci.com/motorcycleinfo/Oils1.html

http://www.racerpartswholesale.com/redtech1.htm

http://www.realclassic.co.uk/techfiles/oil030319.html

http://www.castrol.com/castrol/gener...tentId=7017050

[jjuddz]

Hate to sound like a shmuck, but whats so bad with the Motorcraft oil that comes in it?

[Warlok]

Im sure that Mobil 1 and all the other expensive synthetic oils are good. My problem with the oil was its viscosity. 5w20? are you kidding me? I mean thats like sewing machine oil to me. So thin I cant believe its able to protect the engine in my 07 GT.

But I'm old school and all my other play toys ran on Castrol 20w50 racing oil. Doing this would be a big mistake on my new GT, and no one has suggested it. But why not just trust that Ford knows more than most of us here, and run the Motorcraft 5w20 and Motorcraft filter that is designed for the modular 4.6 in stock form.

Short of running a supercharger, I think the semi-synthetic is fine from Ford. And as stated here allready, its very true that the main and rod bearing clearances are close as hell on the mod-4.6 and the bearings are wide. This is one of the reasons this oil is needed, not the only oil that will work sure, but why go there?

Lastly, it only costs $18.95 at my dealer to have 6 quarts of Motorcraft oil and new filter replaced, and they get rid of the oil instead of me. I cant hardly do it my self for less, and so every 3000 miles my butt shows up at the dealer to have this done. The record of my timley oil changes looks good on my record's with Ford.

[oldernewbie]

+1

[ponyup]

No disrespect but :
Old school for sure......
20w-50 conventional oil=1950 slide rule
5w-20 synthetic =2007 computer

Another reason manufacturers are using synthetic oils is it helps them with the mileage ratings.
Motorcraft synthetic blend for me, at least until the s/c is installed!

[Goldenpony]

Originally Posted by MaverickMLFD371 Mobil 1, use it in all my vehicles, never looked back!

+1

[Goldenpony]

Sorry-double post

[Goldenpony]

Originally Posted by Jucostud Originally Posted by ponyup My '06 GT came with a synthetic blend which is recommended in the owners manual. The gains in going to a full synthetic are very marginal. The modualr engines are built to much tighter tolerances than your '71 engine was. For this reason alone a synthetic blend or full synthetic is desireable due to it's ability to flow into those tighter places. Basically, it's a personal choice but I'm sticking with the syn. blend for now. they say you get an extra 9 hp with royal purple.

BS!

[Drgnracin72]

you wont get any extra hp form an oil. but why go with a thicker oil than 5w-20, modular motors allready make pleanty of oil pressure and theres no reason to run a thicker oil

[TheUNZippee!]

The car is designed to run 5-20. The only other option your dealer will agree is acceptable is 5-20 synthetic. All you have to do is a little internet research, or go down to your local reputable speedshop, to find out that for a streetcar that will be driven harder than your average grocery getter, synthetic is the way to go. Not because it makes more power, but because it doesn't break down as quickly as conventional oils & thus offers your motor better protection over the course of your oil change interval, and subsequently over the life of your engine.

[Modern_Muscle]

Everyone has their Biases...I use Royal Purple with K&N Filters, always have, always will. Amsoil is another great full synthetic to run. Royal Purple advertises, as well as Brenspeed that they gained from 9 rwhp to 12rwhp just by switching to it. RP also has patented additives to help your engine out (as do all supposedly)...The gains are due to better lubrication and less friction, friciton being the enemy of horsepower...Its also made in Texas, and being a Texan, Support our brands...

[miafan]

Originally Posted by Modern_Muscle Everyone has their Biases...I use Royal Purple with K&N Filters, always have, always will. Amsoil is another great full synthetic to run. Royal Purple advertises, as well as Brenspeed that they gained from 9 rwhp to 12rwhp just by switching to it. RP also has patented additives to help your engine out (as do all supposedly)...The gains are due to better lubrication and less friction, friciton being the enemy of horsepower...Its also made in Texas, and being a Texan, Support our brands...

all synthetic oils claim gains of 9 hp

[TheUNZippee!]

I'm not being confrontational, but I looked all through the information I could find about the Castrol Syntec I use in my ride, and nowhere could I see a claim of any HP gain.