Gena, I must respectfully disagree. Read a few owners' manuals recommendations. Among wordings I've come across are those they will all say S"X" or better or S"X"/GF"#" or better, because API and ILSAC specifications are backwards compatible, but a lot of people don't know that. For my F-150, I'm quite content using Quaker State in SM/GF-4, even though the dipstick calls for SF. I know full well that I cannot find an SF licensed oil any longer, so I buy what's currently available. The "better" wording is just what I've seen, rather than "newer" or "current." I'm not saying that SN/GF-5 is "better" than SM/GF-4. It's just wording that we've come across.
The alternative I've seen, as in my G37 manual, is to show a picture of the contemporary API Donut and Starburst (which in my case shows SM and Resource Conserving and 5w-30) and to advise to choose that viscosity and to "elect only engine oils that meet the American Petroleum Institute (API) certification or International Lubricant Standardization and Approval Committee (ILSAC) certification and SAE viscosity standard." In other words, buy a 5w-30 that is current, with API or ILSAC approval. I'm well aware that my current G37 oil choice of Delvac 1 ESP 5w-40 is outside the formal manual recommendation (SM or newer is called for, GF-4 or newer is an option, and 5w-30 is the preferred viscosity), and I'm not claiming otherwise. Nobody at Imperial Oil showed any indication of panic, however.
I did not suggest that CJ-4/SM is forward compatible with SN/GF-5; they are mutually exclusive based on HTHS alone. However, I will stand by my point that if an engine calls for a 5w-40 in SM or better (as in SM was current when the vehicle's manual was printed), then Rotella in 5w-40 and CJ-4/SM is perfectly valid and fits the certifications called for to the letter. Not every vehicle manual out there requires ILSAC certification, and if they're not calling for an ILSAC grade, they cannot call for ILSAC certification, at least not rationally.
You should be well aware that any vehicle that actually calls for a 40 grade cannot require this to be ILSAC approved, since the HTHS of a 40 grade disqualifies it from ISLAC certification, at least using any modern version of SAE J300. It would be just as silly to ask for a 5w-40 in A1/B1 A5/B5, since the specifications are mutually exclusive to the grade. Also, don't mention low-SAPS or SA levels unless you really want to take a look at the numbers. Rotella 5w-40 obviously will have higher levels than an SN/GF-5 oil, but certainly lower levels than the A3/B3 A3/B4 competition, including such oils in Shell's own lineup. Fortunately, the ACEA E7, E9 ratings of Rotella 5w-40 keep the TBN high and the SA comparatively low.
So, no, Rotella 5w-40 isn't the specified choice for a vehicle calling for an SN/GF-5 oil. Rotella 5w-40 cannot obtain ILSAC approval. However, Rotella 5w-40 CJ-4/SM is a perfect choice if an engine calls for a 5w-40 in SM, and there are a few people on BITOG who require such a lube.
Alternative, Imperial Oil has no such CYA attitude with respect to Delvac 1 ESP 5w-40. They recommend it for high performance gasoline engines specifically, and explicitly remind people of the SM approval.
So, when the owner of a Subaru or another make that calls for, specifically, a 5w-40 in SM asks for my recommendation, which would you prefer I recommend, Rotella 5w-40 CJ-4/SM or Delvac 1 ESP 5w-40 CJ-4/SM?
The alternative I've seen, as in my G37 manual, is to show a picture of the contemporary API Donut and Starburst (which in my case shows SM and Resource Conserving and 5w-30) and to advise to choose that viscosity and to "
I did not suggest that CJ-4/SM is forward compatible with SN/GF-5; they are mutually exclusive based on HTHS alone. However, I will stand by my point that if an engine calls for a 5w-40 in SM or better (as in SM was current when the vehicle's manual was printed), then Rotella in 5w-40 and CJ-4/SM is perfectly valid and fits the certifications called for to the letter. Not every vehicle manual out there requires ILSAC certification, and if they're not calling for an ILSAC grade, they cannot call for ILSAC certification, at least not rationally.
You should be well aware that any vehicle that actually calls for a 40 grade cannot require this to be ILSAC approved, since the HTHS of a 40 grade disqualifies it from ISLAC certification, at least using any modern version of SAE J300. It would be just as silly to ask for a 5w-40 in A1/B1 A5/B5, since the specifications are mutually exclusive to the grade. Also, don't mention low-SAPS or SA levels unless you really want to take a look at the numbers. Rotella 5w-40 obviously will have higher levels than an SN/GF-5 oil, but certainly lower levels than the A3/B3 A3/B4 competition, including such oils in Shell's own lineup. Fortunately, the ACEA E7, E9 ratings of Rotella 5w-40 keep the TBN high and the SA comparatively low.
So, no, Rotella 5w-40 isn't the specified choice for a vehicle calling for an SN/GF-5 oil. Rotella 5w-40 cannot obtain ILSAC approval. However, Rotella 5w-40 CJ-4/SM is a perfect choice if an engine calls for a 5w-40 in SM, and there are a few people on BITOG who require such a lube.
Alternative, Imperial Oil has no such CYA attitude with respect to Delvac 1 ESP 5w-40. They recommend it for high performance gasoline engines specifically, and explicitly remind people of the SM approval.
So, when the owner of a Subaru or another make that calls for, specifically, a 5w-40 in SM asks for my recommendation, which would you prefer I recommend, Rotella 5w-40 CJ-4/SM or Delvac 1 ESP 5w-40 CJ-4/SM?