Amsoil SS 0w40 would be my choice.
Oil
- Thread starter Rainier42
- Start date
Well, why start out using an oil that shears. Why not start out with a better quality Xw40 that won't shear?
We've agreed that Ford's engineers aren't stupid, and they've said that at the very least, the engine needs an oil that meets WSS-M2C931-B. In order to qualify as a "better quality oil", any oil must therefore, at the very least, actually meet WSS-M2C931-B. Beyond achieving that minimum certification, it must also offer performance benefits above and beyond those offered by oils that only barely meet WSS-M2C931-B.
Is there an Xw-40 that does that?
Last edited:
None that I'm aware of but that doesn't mean there aren't Xw-40 oils out there with better properties than Rotorcraft 5w50. Regardless ... Ferrari, Porsche, Aston Martin, McLaren, Mercedes, BMW, GM, Chrysler, VW, etc etc engineers aren't stupid either and none of these others recommend a 5w50 or Motorcraft oil, which is made by Conoco-Philips.
Your point is well made and you are mostly correct. Every manufacturer on your list has their own specifications for engine oils that depend on the engine family. The challenge is the specifications, not the oil products. 5w-50 oils that meet the Porsche A40 spec are included on the A40 list while Ferrari and BMW both require 10w-60 oils for some of their engines. GM has Dexos in two different versions, BMW has LL98, LL01 and LL14 and other variants, an so on. What's important here is that the specs are different and the oils that meet them are different - oils on the Porsche A40 list don't overlap with oils on the Porsche C30 list. Oils on BMW LL-01 don't overlap with oils on the LL14 list. Some oils are on Porsche A40 and on BMW LL-01, but the match isn't 100%.
So, if we accept that oil for a Ferrari should meet Ferrari specs, and oil for Porsche should meet Porsche specs, and so on, then we have to accept that oil for a Ford should meet Ford specs. Once you're got a product over that minimum threshold, the sky's the limit.
If you otherwise don't think that meeting the spec is important, then you're thinking like Dr A E Haas. He posts on a number of boards about running 5w20 oil in his Ferrari Enzo and in his wife's Lambo. He's perfectly rational and he has run low viscosity oils in his cars for a decade with no ill effects. Should everybody do it because he does? I guess it depends on whether you can afford to rebuild an Enzo (or Voodoo) engine if the experiment doesn't work out.
Are you sure that it's the engineers that come up with those ever changing specifications (that only Motorctaft oil can keep up with), and not a bean counter that would like to ensure that more Motorcraft oil is sold? From its inception Motorcraft 5w50 has always been a marketing gimmick.
I'm running Chevron Supreme 5w-20 in my Explorer. It cost me less than $2 a quart with free shipping on Amazon at Christmas. I'm thinking that any oil priced higher than $2 a quart is probably a "marketing gimmick".
Very interesting article and the Motorcraft 5W50 actually comes off looking pretty good. I still prefer the AMSOIL 5W50 for the extended drain interval because at 10 quarts per fill I just can't pay the Ford price and change every 3000 miles, which is about all the miles I will put on this car in a year.
Last edited:
Yes, am questioning the Motorcraft 5w50 oil. This 5w50 starts out with a Kinematic Viscosity at 100 degrees C at a 19 but shears to a 13.6 within 1000 miles. I can start with a higher quality 0w40 that will stay at a 14.8 over the entire life of the oil so it can't be the lubrication property at temperature that Ford engineers are concerned about. My guess is, and as another has pointed out, the issue is the level of Phosphorus in the oil, which Ford engineers are concerned about.
^+1. That's what I use in my '13 Shelby.
I've never seen an Amsoil refinery in my life. They buy the base stocks from someone, and I've heard from a few sources it's Mobil.
From the horses mouth, at least I thought it was his mouth.
What kind of base stocks does AMSOIL use? Are AMSOIL synthetic lubricants PAO-based?
What kind of base stocks does AMSOIL use? Are AMSOIL synthetic lubricants PAO-based?
This goes to the heart of the issue - the challenge is that you have to believe that an oil that shears is "low quality". Like Motorcraft 5w-50, Castrol TWS 10w60, exclusive for BMW "M" cars until 2014 or so, shears to a 10w-50 within 100 miles. But, Ford fills its factory-built race-cars with Motorcraft 5w-50 and BMW Motorsport fills their factory-built race-cars with Castrol TWS 10w-60. Apparently, other characteristics of the oil matter more to the manufacturers than viscosity retention. We don't know what those factors are, just that they're important.
As for the phosphorus thing, while there appears to be only one 5w-50 that meets the 800PPM limit, there are lots of Xw-40 oils that meet it. Redline Euro-series 5w-40 has less than 800PPM phosphorus, for instance. Valvoline Synpower MST 5w-40 is another product with less than 800PPM. I'm sure if I'd looked longer, I'd have examples from Castrol, Mobil and Shell as well. So why didn't Ford change the spec from 5w-50 to 5w-40 so that all those oils would qualify? I have no idea!
Last edited:
Because they want you to buy the oil from them. By changing the specs every time someone else meets them, you maintain the monopoly. It is just not profitable for other oil companies to go through recertification every time Ford decides to change the requirements. The majority of the oil companies don't even offer a 5W50 oil due to the limited market.
Exactly correct.
Blind trust of authority is a dangerous thing. You obviously werent around when the bean counters changed the 5W-30 spec to 5W-20 in 2001 for the exact same Cobra engine. Didnt matter how loud the engineers screamed, Ford was able to save a bundle by meeting CAFE standards. In the engineers words: "whatever you do, do not run 5W-20 weight oil in your 4 valve engine". Even though it was spec'd in the owners manual and on the fill cap.
I think this is the opposite of that situation. Besides, despite all the concern and the "don't do it" advisories, there's no pile of dead engines as a result of switching to 5w20.
https://scontent-lax3-1.xx.fbcdn.net/v/t1.0-9/13179436_1131516170246137_5645703869602823027_n.jpg
Lucas Oil is apparently making a 5w50 for Ford Modulars now. The new bottle above even has the GT350 on it.
http://lucasoil.com/r-d/3149-dyno-and-field-testing
Lucas Oil is apparently making a 5w50 for Ford Modulars now. The new bottle above even has the GT350 on it.
http://lucasoil.com/r-d/3149-dyno-and-field-testing
Dr. Haas proved years ago that factory "recommendations" don't always mean anything. Your intended use of the vehicle can change a lot.
Motorcraft 5W-50 is "sufficient" to get the job done. It rapidly shears to a light 40 grade within 1,500 miles and a heavy 30 grade in less than 5,000 miles. This isn't a trait of a top tier true synthetic formulation, because it's not a top tier true synthetic. It boggles me why people will spend 50K-65K on a Mustang, then rely on a "sufficient" lubricant.
If you want the best 5W-50 on the plant, you choose Amsoil Signature 5W-50. It meets Ford's Ford WSS-M2C931-C specification, has far lower NOACK Volatiilty (evaporation) - less condensed oil in your intake, catch can, valves, combustion chambers, etc. Higher shear resistance, as it will maintain a higher viscosity far longer than Motorcraft. Lower frictional coefficient of a true PAO/Ester synthetic base oil. Lower friction = lower heat, lower wear, and a longer lasting engine. Amsoil 5W-50 has a far longer oil change interval than Motorcraft too. 1 year or 15,000 miles (whichever occur first) in your 8-10 quart sump. I can go on for days, but these are the key points of difference. Do you want "sufficient" or "optimal"?
Now, for street use.....5W-50 is a bit excessive. We've proven this years ago in the GT500 platform. That's why Amsoil's new Signature 0W-40 is the best thing going for your street driven (NO HPDE) GT350. I'd reserve Amsoil's 5W-50 formulation for cars in HPDE events.
Motorcraft 5W-50 is "sufficient" to get the job done. It rapidly shears to a light 40 grade within 1,500 miles and a heavy 30 grade in less than 5,000 miles. This isn't a trait of a top tier true synthetic formulation, because it's not a top tier true synthetic. It boggles me why people will spend 50K-65K on a Mustang, then rely on a "sufficient" lubricant.
If you want the best 5W-50 on the plant, you choose Amsoil Signature 5W-50. It meets Ford's Ford WSS-M2C931-C specification, has far lower NOACK Volatiilty (evaporation) - less condensed oil in your intake, catch can, valves, combustion chambers, etc. Higher shear resistance, as it will maintain a higher viscosity far longer than Motorcraft. Lower frictional coefficient of a true PAO/Ester synthetic base oil. Lower friction = lower heat, lower wear, and a longer lasting engine. Amsoil 5W-50 has a far longer oil change interval than Motorcraft too. 1 year or 15,000 miles (whichever occur first) in your 8-10 quart sump. I can go on for days, but these are the key points of difference. Do you want "sufficient" or "optimal"?
Now, for street use.....5W-50 is a bit excessive. We've proven this years ago in the GT500 platform. That's why Amsoil's new Signature 0W-40 is the best thing going for your street driven (NO HPDE) GT350. I'd reserve Amsoil's 5W-50 formulation for cars in HPDE events.
Last edited:
Oh, looks who's back!
Users who are viewing this thread
