Motorcraft 5W-50 full synthetic

[PeteK]

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.

View attachment 35202

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"Rotella oils are not recommended for gasoline vehicles with catalytic converters.
Best regards,
Shell Technical"

Dated 11/13/13

Xcentric: Diesel cats work differently than gasoline cats. I also suspect that diesel was exempted from the reduced zinc and phosphorus requirement due to its primary use in truck engines.

 

[Beach-GT]

We don't need no stink'in CATs.

 

[DakotaGT]

After perusing all of the oil threads, I must dredge the topic back up again. It has now been several years since many members have started using the Rotella T6 5w-40 synthetic engine oil. I “get” the argument about the integrity of the viscosity holding up over time, but still hesitate regarding the higher ZDDP levels in the Rotella T6. I am still running with cats. Has anybody heard of a GT or GT500 5.4 with verified O2 sensor or cat failures from the Rotella T6? I don’t care about the price difference between oils- just want the best option. With as few miles as I accumulate on my cars, it probably barely matters. After reviewing the topic extensively, I’m inclined to alternate between the Motorcraft and the Rotella with oil changes.

 

[Cobraguy]

I have been using T6 oil in absolutely every vehicle I own right down to my forklifts. Most of them see relatively few miles annually due to our short driving season. Re your O2 sensor question......I’ve only had one intermittently send a code and that is on my old Yukon with 335k on it. its been on T6 since day one and does not use a drop of oil and when changed at 8,000 km intervals the oil looks clean enough to reuse. My DD Roush Raptor is started up in temps down to -40’ with no issues.
Nothing scientific noted here and no recommendations made either way.....just one man’s experience.

 

[Sinovac]

You’re probably not going to live long enough nor put enough miles on your car to damage the cats with T6. I use it in everything except a motorcycle and the NFGT. 190k miles on one vehicle and no problems whatsoever.

 

[DakotaGT]

I have been using T6 oil in absolutely every vehicle I own right down to my forklifts. Most of them see relatively few miles annually due to our short driving season. Re your O2 sensor question......I’ve only had one intermittently send a code and that is on my old Yukon with 335k on it. its been on T6 since day one and does not use a drop of oil and when changed at 8,000 km intervals the oil looks clean enough to reuse. My DD Roush Raptor is started up in temps down to -40’ with no issues.
Nothing scientific noted here and no recommendations made either way.....just one man’s experience.

You’re probably not going to live long enough nor put enough miles on your car to damage the cats with T6. I use it in everything except a motorcycle and the NFGT. 190k miles on one vehicle and no problems whatsoever.

Thank you, gentlemen! I appreciate your thoughts on the matter.