Some ZDDP education
Above is the full text source of the quote below.
"'Despite the pains taken in developing special flat-tappet camshaft wear tests that these new oils must pass and the fact that the ZDP level of these new oils is comparable to the level found necessary to protect flat-tappet camshafts in the past, there will still be those who want to believe the myth that new oils will wear out older engines.- Thanks to Bob Olree GM Powertrain Fuels and Lubricants Group "
I am going to run with source this until I get different data. The bottom line per this 'GM' claiming source is as explained in detail the 800 ppm of zinc additive package is all that was ever needed to protect flat tappets and more was added for other reasons so the newest API standard for gas engines WILL protect flat tappets as well as any motor oil API standard ever produced.
The plan is to stick with 5W-40 Rotella in the tractors and big block Ford and Chevy and other things around the place like mowers etc.
I will work my way to Mobil 1 5W-30 for the 2003 5.3L GM engine with 126K miles.
Short of it is that the need for high zinc for flat tappets is a MYTH.
http://www.api.org/certifications/engineoil/pubs/upload/engineoilguide_march2010.pdf
API Gas/Diesel chart.
GM debunks ZDDP myths for flat tappet cams - Bob Is The Oil Guy
This restates some of the first link but also covers other OIL Myths.
Well Gale, let's hope this plays out as described.
If I had a Leno type problem (untold # of high perf olde school big block classics running really radical cams), then I'd be even more concerned about ZDDP. I get that this class of vintage motor is the worst case for this issue.
A couple of things are nagging at me about the general use scenario though.....
1) The Cat "failures" due to ZDDP contamination has a Create a Crisis, to Drive an Agenda feel to it.
I was reading somewhere recently that the industry couldn't even come up with an agreed upon standard test for this "contamination" issue. My experience, and anecdotal data, indicate that there was very little ZDDP contamination of Cats going on.
2) #1 above leads into #2 - I'll be a little surprised if the EPA stops at 800ppm. We'll see.
3) What does the gubmint consider acceptable Collateral Damage ? I don't know the answer.
If 75% of the old vehicle fleet immediately seized their engines due to an oil spec change, then politically, the noise would probably be unacceptable.
But what if it hits only 0.5%, or even 5% of the old vehicle fleet ? Probably that would be politically acceptable, esp. since it addresses various other agendas.
A good example of the Acceptable Collateral Damage trade-offs that Gubmints are willing to make is the Acceptable Wear Scar limit for ULSD - the US govt mandated a higher limit than the engine manufacturers had spec'd as the maximum acceptable.
Woulda liked to be a fly on that wall, during those closed discussions.....
4) VW has recently had some serious issues with engine lube related wear failures. I don't drive a VW, so I haven't really dug into this research wise, but I keep tripping over discussions of these failures, the last 2 years or so.
I stumbled through a time portal today..... CTC here had some Rotella T5 on sale.
Here (Canada) we get a 0W40 T5 that is CG-4 and SJ rated (ie. no later C or S ratings), full Synthetic. This will be really nice in my tractor in the Winter, as my battery is slightly undersized. I haven't paid too much attention to the T5 before, as the prior grades were semi-synth that sold for pretty much the same price as T6.
Up here at least, Shell seems to be marketing this 0W40 as a modern offering for older spec diesels, and older gas too.
Some other night, I'm going to poke around on BITOG to verify the Zinc and Phosphorus levels of this particular T5.
Rgds, D.
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