Motorcraft 5W-50 full synthetic
- Thread starter Art138
- Start date
Xcentric
GT Owner
Excellent info James! Thanks for posting.
BTW, re the cranking without starting procedure. I watched Rich Brooks do this to my car. He kept his right hand on the key and pressed the start button with his left. This is a safety technique in case the engine starts, if, for example, you ease up on the gas pedal before you stop cranking. If the engine fires you can quickly turn the key off.
BTW, re the cranking without starting procedure. I watched Rich Brooks do this to my car. He kept his right hand on the key and pressed the start button with his left. This is a safety technique in case the engine starts, if, for example, you ease up on the gas pedal before you stop cranking. If the engine fires you can quickly turn the key off.
Wwabbit
GT Owner
bonehead
GT Owner
Great info. But did I miss something? I just bought a case of Motorcraft 5w-50 a few weeks ago. It's still available.
Wwabbit
GT Owner
.... pile of oil and transaxle sample analysis , with Redline and Motorcraft mostly every 400 mi. Haven't had time to compile them yet.
BlackICE
GT Owner
I think what he means is the original oil's formula and part number of changed. Due to gov. regulations the level of ZDDP in all motor oils for gasoline engines have be lowered to extend the life of cats. Diesel oils still have the higher levels of ZDDP.
bonehead
GT Owner
Also the Motorcraft 5W50 that was sold in 2006 under the previous spec was also a full Class IV synthetic. The current Motorcraft 5W50 that Ford says is 'good enough' even though it does not meet the original spec requirements is a Class III hydrocracked synthetic. Very different oil. Class III in and of itself is not a problem, just that it is NOT the oil developed for this engine. Not enough demand in the parts chain to warrant stocking two different formulations of 5W50. In fairness, the Rotella T6 is also a class III synthetic.
Now, real world testing in the actual Ford GT engine has shown the very different results that can be obtained from a higher quality lubricant. The difference in results are not minor. The current Motorcraft 5w50 at less than 1000 miles use is nearly a 30wt oil. It shears that badly. The wear metals in the 1k Motorcraft sample are also higher than in the 5500 mile Rotella sample. No idea how bad it would get in 5500 miles. Not going to subject my GT to that kind of abuse.
I don't work for Shell or Motorcraft, buy whatever you want. I was just sharing what I had learned so that others may benefit if they wish. I very much look forward to seeing Wwabbit post his oil analysis results.
Now, real world testing in the actual Ford GT engine has shown the very different results that can be obtained from a higher quality lubricant. The difference in results are not minor. The current Motorcraft 5w50 at less than 1000 miles use is nearly a 30wt oil. It shears that badly. The wear metals in the 1k Motorcraft sample are also higher than in the 5500 mile Rotella sample. No idea how bad it would get in 5500 miles. Not going to subject my GT to that kind of abuse.
I don't work for Shell or Motorcraft, buy whatever you want. I was just sharing what I had learned so that others may benefit if they wish. I very much look forward to seeing Wwabbit post his oil analysis results.
Just a minor point, but the Rotella T6 is not a diesel specific formula. It is for diesel and gasoline engines and is certified to the API SM spec. It is primarily marketed to the diesel fleets however it has gained significant ground in the motorcycle and forced induction sports cars areas because of its high shear strength and very low wear. Its intended for fleet wide use, not just diesels. I do not think the very low zinc and phosphorous requirements imposed in API SM effect 5W40 and 5W50 weights.
FENZO
GT Owner
Considering how dogmatic folks are about this, I must be smoking hydrocrack for bringing it up.... but I'm willing to fly over this Maginot line for the benefit of my engine. I've always sworn by the MC, but like Goodyear vs Bridgestone maybe it's time to change. Maybe not.
Compile those results Wwabbit?
GTMikey
GT Owner
BlackICE
GT Owner
andymlow
GT Owner
Well I hope JCThorne is right because I just put T6 in my car. Low mileage car but I didn't like the fact the Motorcraft changed the oil from the original spec.
If it makes you feel any better, I will confirm that I still practice what I wrote. My GT is still running the Rotella T6, on its third refill with about 5000 on each of the previous two. Blackstone results each time are very good with low wear metals and still within viscosity spec and base number. Its a very good fit.
Beach-GT
GT Owner
Rotella T6 is only available in 5W40. I will say that Motorcraft 5.50 does NOT meet viscosity requirements for a 5W50 oil at operating temperature after a few hundred miles. It actually shears to a viscosity much thinner than the Rotella. That is the problem with the MC where the Rotella holds its viscosity grade over its service life.
Xcentric
GT Owner
Oil change today with Rotella. Some time ago, I found this on Wikipedia. You can find various similar versions on the web. My car has long tube headers. Based on this, I would not have used the Rotella with catalytic converters in a state with tough emissions inspections. IDK why diesel engines with cats would be any different, but I didn't pursue the issue with Shell.
Sorry, that png file doesn't display full size. Here's the essential text:
"Rotella oils are not recommended for gasoline vehicles with catalytic converters.
Best regards,
Shell Technical"
Dated 11/13/13
Sorry, that png file doesn't display full size. Here's the essential text:
"Rotella oils are not recommended for gasoline vehicles with catalytic converters.
Best regards,
Shell Technical"
Dated 11/13/13
Last edited:
Sinovac
GT Owner
Rotella must say that because of the higher zinc content can damage converters over the very long term. I use it in everything now except my Harley.
Xcentric
GT Owner
Yes, and I suppose that's why the containers are labeled "diesel." But, is there something different about diesels with cats? My diesel has cats, AdBlue. Just curious why the added ZDDP would be bad for long term use in gasoline engines with cats, but not diesel engines with cats.