Red Line 5W-50 2011 GT500 Shelby - high oxidation

[Unleashedbeast]

Originally Posted By: SIXSPEED
Originally Posted By: Unleashedbeast
I guess the idea of Red Line 5W-50 wasn't the best idea since it doesn't shears rapidly like Motorcraft 5W-50. It retains a viscosity that I have proven to be to much for a Ford modular driven on the street.

Their 5W50 HTHS viscosity of 5.9 cSt is higher than necessary for our cars too IMO.


When I had Amsoil 20W-50 in the Shelby, I could tell the starter required more efforts to turn over the engine. Users of Red Line 5W-50 are reporting the same. Have you had similar experiences with Mobil 5W-50?

Assuming the lubricant someone were using had a lower than required HT/HS, wouldn't that show excessive wear metal ppm in a UOA?

Why would the Shelby require so much more HT/HS than the Terminator?

 

[d00df00d]

Originally Posted By: Unleashedbeast
Assuming the lubricant someone were using had a lower than required HT/HS, wouldn't that show excessive wear metal ppm in a UOA?

Not necessarily.

As I understand, minimum HTHS requirements still account for the worst case scenario (or something close to it): high oil temps, hard use, heavy fuel dilution, used oil, etc. If those conditions do not apply, or if the oil just has some trick chemistry, it's possible that a lower-than-spec HTHS might not lead to excess wear.

Also, not all types of excess wear produce wear particles that will show up on most UOAs. In fact, it has been argued that most UOAs are more likely than not to miss serious problems because they do not count particles in the right range of sizes.

 

[SIXSPEED]

Originally Posted By: Unleashedbeast

When I had Amsoil 20W-50 in the Shelby, I could tell the starter required more efforts to turn over the engine. Users of Red Line 5W-50 are reporting the same. Have you had similar experiences with Mobil 5W-50?

Why would the Shelby require so much more HT/HS than the Terminator?

I don't notice the starter ever struggling to crank the motor. The recommended Motorcraft 5W50 has a minimum HTHS of 3.7 cSt to meet the SAE J300 API requirements of a 5W50 oil; so I assume this is all that the GT500 motor needs ... and I am well aware how the MC oil viscosity shears with use.

 

[Ben99GT]

Originally Posted By: Unleashedbeast
Originally Posted By: SIXSPEED
Originally Posted By: Unleashedbeast
I guess the idea of Red Line 5W-50 wasn't the best idea since it doesn't shears rapidly like Motorcraft 5W-50. It retains a viscosity that I have proven to be to much for a Ford modular driven on the street.

Their 5W50 HTHS viscosity of 5.9 cSt is higher than necessary for our cars too IMO.


When I had Amsoil 20W-50 in the Shelby, I could tell the starter required more efforts to turn over the engine. Users of Red Line 5W-50 are reporting the same. Have you had similar experiences with Mobil 5W-50?


Amsoil 20W-50 is actually pretty thin compared to Red Line 5W-50 (5.0 vs 5.9 HTHS viscosity).

 

[Unleashedbeast]

Originally Posted By: d00df00d
As I understand, minimum HTHS requirements still account for the worst case scenario (or something close to it): high oil temps, hard use, heavy fuel dilution, used oil, etc. If those conditions do not apply, or if the oil just has some trick chemistry, it's possible that a lower-than-spec HTHS might not lead to excess wear.


Which is the reason why I have been experimenting with lighter viscosity formulations in the Shelby. I have yet to see the need for a 5W-50 lubricant viscosity required in the Shelby for street, aggressive street driving, and drag racing. These applications do not get the oil hot enough to constitute that heavy of a lubricant. Since I'm also using a cooler thermostat, the oil cooler will reduce oil temps more than the stock thermostat did. Reducing oil temps increases viscosity. Doesn't a thinner lubricant also cool the engine better? I've heard some say that a thinner lubricant will cooler faster, and also helps with retaining a slightly higher viscosity in the lubricant due to a more rapid cooling rate.

Hot oil pressures on the street were too high with a lubricant of 14.6 cSt @ 100*C. They would be worse using a lubricant of 18.9-20.9 cSt @ 100*C. It was very easy to reach the pressure of oil pump bypass, and that would cause some of your oil volume to be diverted back to the oil pan.

Road racing is a different story, but I don't road race my car. I've still yet to understand why the 5.4L Shelby engine is spec'd for a 50 grade, but the 4.6L Terminator was a 30 grade. Both engine produce similar horsepower output levels form a stock engine. Ford is also comfortable with Motorcraft 5W-50 shearing to a heavy 30 grade lubricant. This says a lot.

"as thin as possible....as thick as necessary."

 

[d00df00d]

Originally Posted By: Unleashedbeast
Doesn't a thinner lubricant also cool the engine better?

Yes.


Originally Posted By: Unleashedbeast
Ford is also comfortable with Motorcraft 5W-50 shearing to a heavy 30 grade lubricant. This says a lot.

Agreed.


Originally Posted By: Unleashedbeast
"as thin as possible....as thick as necessary."

 

[wag123]

Originally Posted By: A_Harman
I would say go back and try again with Redline 10w-40. Fewer VII's may reduce oxidation. This would be a good UOA to show to Redline and get their comments.

+1
Too much VII in 5w50. Even a quality synthetic has to have some VII in it to achieve this kind of spread. IMHO, a full synthetic 10w40 would be a more suitable choice. There is very little VII in a synthetic 10w40.

 

[Unleashedbeast]

Originally Posted By: wag123

+1
Too much VII in 5w50. Even a quality synthetic has to have some VII in it to achieve this kind of spread. IMHO, a full synthetic 10w40 would be a more suitable choice. There is very little VII in a synthetic 10w40.


I agree 100%, and have noticed much better results from true synthetic 10W-40 than 5W-50, not so much in wear, but in efficiency.

 

[steve20]

wouldn't an oil temp guage be of enormous help here?

My Corvettes spec syn oil cause they do not come from the factory with oil cooler----but they do have digital oil temp gauges. I run 'em easy in rural driving and the highest oil temp I've seen is 235--because of this, I do not even use syn oil-cause with the temps I'm seeing there is no need for it, and the engines are exponentially quieter on dino. What I'm getting to is maybe Ford (and GM) haves sped'ed this grade oil to meet worst case (track) conditions--otherwise a lighter grade oil will do just fine

 

[Unleashedbeast]

Originally Posted By: steve20
What I'm getting to is maybe Ford (and GM) haves sped'ed this grade oil to meet worst case (track) conditions--otherwise a lighter grade oil will do just fine


You are correct, and evidence of this fact was presented with the release of the new "Roadrunner" 5.0 engine in the 2012 Boss. It's spec'd for 5W-50 while the "Coyote" 5.0 is spec'd for 5W-20. The difference is the "intended" usage of the Boss.