5W-50 Full Synthetic Oil Recommendation

[SLF360]

I just read the PDS for Castrol Syntec 5W-50, and it states, "Exceeds all car and light truck manufacturer's warranty requirements for the protection of gasoline, diesel and turbocharged engines where API SM, SL, SJ, SH, CF or CD is recommended" even though the oil is certified to the WSS-M2C931-A specification and not the WSS-M2C931-B specification.

AND:

I talked to Castrol (they have a lot of ties with Ford) and they specifically told me and so did Ford that it is not approved by Ford at this time. Castrol expects to be approved by the middle of ...07. Some will think I am splitting hairs here but the reality of it is, if for any reason you have engine problems and did not meet there requirements for any reason (and they will ask for receipts) you void their warranty. I have gone over this subject extensively with the Factory rep (Ralph Arning), Castrol, Mobil 1 and the dealership. Take it for what it is worth, $18,000.

NOTE: I wonder why their engines are cheaper than ours?

nteresting find Richard,

I guess my GT will receive only Motorcraft then. I use the Castrol on the BMW, and am very happy with it so far. Gotta get 5ltr canister over fast then. Any one know how to source Motorcraft in Europe here best ? Neil, any idea ?

Stefan

 

[SteveA]

nteresting find Richard,

I guess my GT will receive only Motorcraft then. I use the Castrol on the BMW, and am very happy with it so far. Gotta get 5ltr canister over fast then. Any one know how to source Motorcraft in Europe here best ? Neil, any idea ?

Stefan

Stefan, I agree and will use Motocraft as well.
Back when I was younger and had hair I raced and built Bikes and motorcycles, mostly 2-strokes but a few Kieth Black fuel motors as well. After only a few hours of hard running or a pass down the strip, I would tear them down and it was easy to see which oils worked best. Surprisingly Torco was one of the best with both 2-strokes and 4-strokes.
Here is my problem with the GT and other motor vehicles I own. How do you know if your happy sense I don't think any of us will be tearing this thing down to inspect for wear or discoloration due to heat?

 

[richardhead]

Again, note on the Quaker State Oil post by "Blackice", it does not specify Quaker State meets or exceeds API SM specifications. The Ford oil does, as does the Castrol. However, the Castrol does not meet the "-B" Ford specification.

 

[richardhead]

Here is some discussion, for what it is worth, from our related Ford owners at the Shelby GT500 site ( www.fordgt500.com ):
......Take it for what it is worth, $18,000.

NOTE: I wonder why their engines are cheaper than ours?

It seems the Shelby uses a cast iron block, different clutch system and may not have the dry sump oiling system (Couldn't figure it out from the Ford site information). That could explain the cost differential (GT is $36,000 list from Ford Racing, and the Shelby must be about $18,000)

 

[Indy GT]

Factory Fill

This is an interesting topic and I heard the same line as shared by Doccars, that the Motorcraft 5W-50 was supplied by Conoco.

In researching, I called Mobil's questions and comments line (1-800-275-6624) and spoke to Matt. He seems knowledgable and says the 5W-50 although primarily a Moble 1 european viscosity blend, is the "factory fill" oil used by Ford in the GT. So if he is correct (have a call into some Ford friends) the 5W-50 version of Mobile 1 is what our cars left Wixom with. He did say the 5W-50 does have limited distribution here in the states but you must go through the Exxon/Moble jobber or wholesaler to get this particular product. It is not retailed in the states.

 

[everetto]

Interesting regarding Mobil One possibly being used in GTs at assembly. As my earlier post also stated, Mobil One in this weight may be available from select distributors - call the number listed.

Now I am going to drop a bomb on this discussion FOR THE PURPOSES OF SHARING KNOWLDEGE, AND LEARNING. Talking about oil is similar to talking religon - most are entrenched in their beliefs, and won't be changed, so it is often an emotional topic.

Here is the bomb; I am an engineer (mechanical), and I have heard for years from many sources (MEs, ChemEs, Material Science guys, Automotive engineers) that to create a blend with such a wide range (5 to 50) you start with a BASE 5W oil, and then add huge amounts of polymers to "give" you the 50W at high temperatures. These polymers are what make up products like STP. These polymers shear and break down fairly quickly relative to oil life, leaving you with a 5W base oil that does not thicken up to heavier viscosities after some period of time.

I would be interested in comments based on technical information, as that is what my post is based on. My personal opinion is that there is some merit to the point and with that said, I may investigate oils with somewhat narrower ranges, or an oil that is blended from a base 10W, which might retain somewhat heavier viscosities a bit longer over the oil life.

 

[BlackICE]

Automotive engineers) that to create a blend with such a wide range (5 to 50) you start with a BASE 5W oil, and then add huge amounts of polymers to "give" you the 50W at high temperatures.

I heard that too. It has been posted here that without that 50 high end you will lose power due the the valve lifters compressing the oil out. So the 50 high end is needed. Now is the 5w really necessary given most of the cars are never driven in cold weather. The 5w is needed during starting and warming up of the engine. If you never start your GT in temperatures lower than 55F you may not need the 5w, like owners in CA, or FL a 10w-50 may work OK. I would think so, but the Ford warrantee may not!

BlackICE

 

[AJK]

I always thought that the numbering system indicated the lowest ambient temperature that you expect to do a cold start determines the maximum first "weight number" and the one followed by the 'W" is its multiviscosity grade. The oil acts like a 50 weight at high temps but will allow good starting qualities at temps as low as 5 degrees F. Thus 5w50. I didn't think that the oil actually changes viscosity, it just functions as any oils within the range.

 

[BlackICE]

Yes, the oil doesn't change viscosity, but multi grade don't "thin out" as much as single grade so they behave like low weight oil at low temps and higher weight oil at high temps. All grades of oil become less viscose as the temps rise, but the change is less extreme in a multi grade. I think the 5w represents the viscosity that a standard single grade oil would have at a low temp (maybe 0 C) and the high number 50 would represent the viscosity of the oil at 100 C.

BlackICE

 

[Shadowman]

This topic comes up with most every marquee and with very few expection the OEM; in this case Ford does not produce the oil they only spec it as such it could be presented by any of a variety of companies. The dictated specifications are what matter whenever a product not purchased from the OEM is selected. Lamborghini as one example want you to use Agip and the same holds true for GM...... Honda......Toyota..... they all have their fingers in the $$ chain as the result of their relationship with a given oil company at any given moment.

Having shared this whether Castrol or ?????? numerous of companies have premium oil that will insure a long and trouble free life in these gals.

Takes care

Shadowman

 

[Indy GT]

Moble 1 Update

As promised, I checked with internal Ford sources regarding the Moble 1 "Factory Fill" related to me on the Mobil phone line. Fact is, Moble 1 is NOT the OEM oil shipped in our GT. The factory fill GT product is manufactured by Conoco/Phillips (nod to Doccars for his correct memory) and is blended for Motorcraft per their specification. The Motorcraft oil is frequently overchecked to ensure compliance to the blending spec by actual internal durability testing.
Just reinforces my thought, even though the Motorcraft oil is a bit expensive, $100 for oil in my $36K engine is trivial. I, as many previous postings indicate, plan on using the Motorcraft oil for peace of mind and just one less thing to worry about.

Incidently, the 5W low side of the recommended oil viscosity is for cool (or cold) weather starting AND fuel economy. The 50 wt on the high end is not for lifter compression but for main/rod bearing film strength under the higher combustion pressures of our blown engine.

Richardhead, you are correct the 5.4 used in the Shelby 500 is a cast iron block (GT is alum) and the Shelby engine has a wet sump while the GT is dry. The GT block also has additional "high-performance" features which make it more "robust" relative to the 5.4 used in the Shelby.

 

[SLF360]

Incidently, the 5W low side of the recommended oil viscosity is for ....fuel economy.

That's a great recommendation for the oil then ! :biggrin :biggrin :biggrin

 

[timcantwell]

One thing that my engineer friends at Lubrizol told me (they sell all the modifyers and chemistry to all the motor oil manufacturers) is that low-number is not only important for cold-starting (dry) lubrication, but this number is also the where your oil ends-up after shear breakdown over time. In other words, if you are using a "0-W 50" grade it gives you the best all-round protection (WHEN THE OIL IS NEW). Age, heat-cycling, and shear break-down will reduce the oil to a "0-W-0" over time. Hence, Ford specified a 5-W-50 to ensure protection over wear and heat cycles as it will break down to a "5-weight" when it is "broken down".

 

[everetto]

...but this number is also the where your oil ends-up after shear breakdown over time.

Which is exactly what my post said.

 

[Sinovac]

I'm certainly no expert but...

I think the 5w-50 has a base weight which is too light for hotter climates like Florida where I live. I have used the "factory recommended" 5w multi-viscosity oils in high performance motorcycles and have actually experienced rod knock in very hot weather-NOT a good thing. When I switched to a higher weight multi-vis oil, no more knock, although the oil I used was not "factory recommended".

In my humble opinion, the factories specify oil weight based on meeting fuel economy targets such as CAFE (thus the "energy conserving" designation for the lighter oils) and EVERY possible parameter under which the engine will operate (i.e. extreme cold to extreme hot) since most car owners don't/won't use the proper oil for their particular climate. Most vehicle manuals have a chart which show the proper weight oil based on the expected operating temperatures but the GT manual does not for unknown reasons.

In the good (bad?) old days, I changed my oil to a lighter weight in the winter and heavier in the summer. While multi-vis oils have obviated the need to do this to some point, the basic rationale is the still the same.

I have always used 15w-50 Mobil 1 and have never experienced a failure, even in high mileage vehicles. This weight provides sufficient cold weather protection during Florida winters. However, it would not be the proper oil to use in colder climates.

Again, I am no expert but I think it would be a mistake to assume that the"factory recommended" oil weight is the absolute best choice for ALL climates. Some engineer may say I'm an idiot, but experience tells me otherwise.

 

[BlackICE]

I think the 5w-50 has a base weight which is too light for hotter climates like Florida where I live...

I have always used 15w-50 Mobil 1 and have never experienced a failure, even in high mileage vehicles...

I agree! I am in CA in won't see many temps below 50F. So 15w-50 would work fine in my opinion. However Ford's warrantee dept may differ.

BlackICE