Just some magazine interview with Rotella T engineer, high perf Pontiac or HotRod/CarCraft, can't recall which.
I'll see what I can find.
There is a reason that car oils aren't approved at ALL for diesels.
The higher levels of ZDDP are good for antiwear, but bad for Cat converters, so the car oils are dropping the levels more and more, the diesel's aren't at near the rate. They need the higher antiwear properties.
Even cam companies are recommending diesel oils on flat tappet cams to help stave off lifter/cam wear. The last paragraph is the one that is why I run Rotella T Synthetic.
Edit:
http://www.highperformancepontiac.com/tech/hppp_0606_understanding_motor_oil/index.html
Edit:
http://www.highperformancepontiac.com/tech/hppp_0802_pontiac_performance_engine_oil/index.html
Juggling The Truth About Today's Oil - Engine Oil Tech
Shell Rotella T
Designed for the harsh environment within a diesel engine, Shell ROTELLA T has aptly earned the reputation as a high-quality, maximum-protection lubricant. With the reformulation of gasoline-engine oil a few years ago, many hobbyists with flat-tappet camshaft engines have found salvation in commercial-grade oils like ROTELLA T, which have typically maintained high levels of the desirable anti-wear additives.
Oil Formulation And Flat Tappet Cams Shell Rotella T
Produced by Shell, commercial-grade...
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Oil Formulation And Flat Tappet Cams Shell Rotella T
Produced by Shell, commercial-grade ROTELLA T has been a popular off-the-shelf choice for flat-tappet camshaft engines, but rumors of recent reformulation have sent hobbyists scurrying for options. The truth is that the current API CJ-4 category rating offers enhanced levels of anti-wear protection and, according to Shell, ROTELLA T was designed with flat-tappet camshaft protection in mind.
The '07 model year brought on many changes for diesel engines. Among them was an exhaust system catalyst, and another oil classification standard-CJ-4. One would assume from past events that the addition of said exhaust catalyst would ultimately lead to ZDDP reduction, but Shell's OEM Technical Service Manager, Stede Granger, says otherwise.
High Performance Pontiac: You're likely aware that ROTELLA T is used by many automotive hobbyists with flat-tappet camshafts. Are there any negative effects when using commercial-grade oil in gasoline engines?
Stede Granger: Assuming we're speaking about older gasoline engines that are no longer under warranty, and emissions aren't a concern, there are no major negative effects when using ROTELLA T. In fact, it carries an API S-series category rating. The only possible concern I see is viscosity-15W-40 will not circulate as quickly during initial start-up in extremely cold climates as a lesser viscosity, and our 5W-40 synthetic is then an option.
HPP: We've heard that the current CJ-4 category rating has significantly reformulated diesel oil for 2007. Can you elaborate on that?
SG: Most diesel engines for 2007 utilize an EGR system, an exhaust catalyst, and a Diesel Particulate Filter (DPF) to help lower emissions, and the new CJ-4 category is designed to ensure that there are no detrimental effects to this equipment, maximizing its service life.
HPP: Does the addition of an exhaust catalyst mean a drastic reduction of the high-pressure wear additives found in ROTELLA T oil?
SG: The exhaust catalyst found on diesel engines isn't the same as that of a typical passenger-car application, so we're able to retain high ZDDP levels. The API specification change to CJ-4 for 2007 has resulted in moderate zinc reduction from about 1,400 ppm to 1,200 ppm. And even at these slightly decreased levels, ROTELLA T 15W-40 conventional and 5W-40 synthetic still contain three to five times the amount of the desirable anti-wear additives as some current gasoline-engine oils.
HPP: Is there any chance your company could reformulate ROTELLA T in the near future, and drastically reduce its high-zinc content?
SG: Historically speaking, commercial-grade oil classification changes occur every two to four years, but the new CJ-4 category offers the best all-around protection of any previous rating. So I feel there's little reason for any immediate change, and expect to see it around for at least a few years.
A point to remember is that zinc not only protects flat-tappet camshafts against wear, but also any high-pressure metallic surface that relies on pressurized oil for lubrication, such as the piston rings, cylinder walls, and rocker arms/pushrods. When oil can't carry the load, zinc steps up and creates a chemical barrier, and the high levels of zinc in commercial-grade oil contribute to the fact that some diesel engines run a million miles or more. I don't see us reducing the zinc content in ROTELLA T unless an organization like API imposes a lesser chemical limit on a subsequent category.
I apologize for the thread jack. Does anyone here have any real hands on proof that Rotella syn is more effective than our normal syn oils? Not looking for empirical rocket scientist data but just someone with actual experience with the pros and cons of Rotella.
Btw Billy, hows the cold treating you nowadays?