cruiser54

Rotella and Wix. Like peas and carrots.

belvedere

From what I know, ZDDP limits did not change from SM (Rotella T6) to SN (Maxlife). Do you have a reference that says otherwise? The Valvoline Maxlife PDS lists Zinc and Phosphorus levels, but I can find nothing on Shell's site for Rotella. Do you have a link to a Shell spec sheet? If not, where did you get your info on Zinc levels?


http://www.valvoline.com/pdf/maxlife.pdf



Yes, I'm sure the junkyards are littered with countless vehicles (and lawnmowers) ruined by Maxlife.


Costs more than what? Conventional oil? Umm, yeah, I suppose, it's a synthetic blend.


I simply used Maxlife as an example. Any of the HM oils would be a great choice. They are, in general, high quality, robust oils, and many (not all) are synthetic blends. Valvoline Maxlife, QS Defy, Pennzoil HM, Mobil HM...take your pick. To me, for an engine with that many miles (especially our Jeep engines!), the extra seal conditioners sure wouldn't hurt, either.


The Rotella T6 would be great, too. But for someone in a northern (cold) climate, I'm not sure a xW40 is needed. I simply offered another option; either would serve well.


BTW, what's the obsession with Zinc? (If it's even higher in the Rotella; I haven't seen any evidence.) These aren't race engines with high-lift cams and crazy valve spring pressures.

salad

Go check the thread in my signature. I think MaxLife is called that just because it's a synthetic. It doesn't appear to be a high mileage oil.

belvedere

Maxlife is indeed a HM oil, available in both syn blend and syn.


http://www.valvoline.com/products/br...age-motor-oil/

salad

I couldn't care less about what their marketing says it is. Based on actual tests that measure additive levels it's just another API SN. Nothing special.

belvedere

The typical benefits of a HM oil are reduced oil consumption and seal conditioning. Depending on mfr, the first benefit could be achieved through the addition of some syn oil (lower volatility) or simply slightly higher viscosity oil. The seal conditioners are normally esters. Neither of these things would show up as "additive levels" on a VOA/UOA.

salad

Both of which are covered quite well by API SM and SN standards, and very common in reputable synthetic oils. This isn't 1992 anymore. "High Mileage" is a marketing term that doesn't mean anything specific and I don't for one second believe any claim as to performance without any data. There are plenty of conventional HM oils that do not have suped-up seal conditioning and are no different from SN oils in reducing consumption.

With anti-wear additives nearly absent from a lot of today's oils the 4.0L's seals are the least of our concerns...

belvedere

I can only assume you're referring to reduced levels of ZDDP. There are many other anti-wear additives used in today's oils. SM/SN have much more stringent wear tests than previous standards. Any SM/SN oil will provide good protection in a 4.0.


Again, the ZDDP limits did not change from SM to SN. Rotella T6 meets SM, so if SN oils do not have adequate ZDDP levels for your taste, then T6 won't either. Both SM and SN use the same Seq. IVA cam wear test, so nothing has changed in that dept.

salad

You obviously haven't read the research presented in my thread. Not going to repeat it all here.

belvedere

Don't have to. From the statements you're making, you're misinformed. I could find all kinds of internet lore to say just about anything, but the API tests stand as fact. ZDDP levels are reduced, and replaced by other AW adds. No big deal. The modern oils provide better performance than ever.

belvedere

I'll make it easy: tell me specifically what you're disputing, and I'll address it with proof, not internet folklore.

belvedere

OK, a quick read through Page 1 of your Oil Saga spotted this, which I believe to be the basis for a lot of your misconceptions:

A common error perpetuated on the 'net. The SM/SN cam wear test DOES NOT use a roller cam. Since you obviously don't believe anything I tell you, I'll paste a quote from a GM service bulletin:


The Starburst Oil Myth -- The latest myth promoted by the antique and collector car press says that new Starburst/ API SM engine oils (called Starburst for the shape of the symbol on the container) are bad for older engines because the amount of anti-wear additive in them has been reduced. The anti-wear additive being discussed is zinc dithiophosphate (ZDP).

Before debunking this myth, we need to look at the history of ZDP usage. For over 60 years, ZDP has been used as an additive in engine oils to provide wear protection and oxidation stability.

ZDP was first added to engine oil to control copper/lead bearing corrosion. Oils with a phosphorus level in the 0.03% range passed a corrosion test introduced in 1942.

In the mid-1950s, when the use of high-lift camshafts increased the potential for scuffing and wear, the phosphorus level contributed by ZDP was increased to the 0.08% range.

In addition, the industry developed a battery of oil tests (called sequences), two of which were valve-train scuffing and wear tests.

A higher level of ZDP was good for flat-tappet valve-train scuffing and wear, but it turned out that more was not better. Although break-in scuffing was reduced by using more phosphorus, longer-term wear increased when phosphorus rose above 0.14%. And, at about 0.20% phosphorus, the ZDP started attacking the grain boundaries in the iron, resulting in camshaft spalling.

By the 1970s, increased antioxidancy was needed to protect the oil in high-load engines, which otherwise could thicken to a point where the engine could no longer pump it. Because ZDP was an inexpensive and effective antioxidant, it was used to place the phosphorus level in the 0.10% range.

However, phosphorus is a poison for exhaust catalysts. So, ZDP levels have been reduced over the last 10-15 years. It's now down to a maximum of 0.08% for Starburst oils. This was supported by the introduction of modern ashless antioxidants that contain no phosphorus.

Enough history. Let's get back to the myth that Starburst oils are no good for older engines. The argument put forth is that while these oils work perfectly well in modern, gasoline engines equipped with roller camshafts, they will cause catastrophic wear in older engines equipped with flat-tappet camshafts.

The facts say otherwise.

Backward compatability was of great importance when the Starburst oil standards were developed by a group of experts from the OEMs, oil companies, and oil additive companies. In addition, multiple oil and additive companies ran no-harm tests on older engines with the new oils; and no problems were uncovered.

The new Starburst specification contains two valve-train wear tests. All Starburst oil formulations must pass these two tests.

- Sequence IVA tests for camshaft scuffing and wear using a single overhead camshaft engine with slider finger (not roller) followers.

- Sequence IIIG evaluates cam and lifter wear using a V6 engine with a flat-tappet system, similar to those used in the 1980s.

Those who hold onto the myth are ignoring the fact that the new Starburst oils contain about the same percentage of ZDP as the oils that solved the camshaft scuffing and wear issues back in the 1950s. (True, they do contain less ZDP than the oils that solved the oil thickening issues in the 1960s, but that's because they now contain high levels of ashless antioxidants not commercially available in the 1960s.)
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.
Like other myths before it, history teaches us that it will probably take 60 or 70 years for this one to die also.

Special thanks to GM's Techlink
- Thanks to Bob Olree – GM Powertrain Fuels and Lubricants Group

Markb

While on the subject of which oil and which filter; my reading here convinced me to use the Shell Rotella, and the 4.0 l really seems to like it , but there is not a NAPA handy, and where do you get a Wix? the local Advance Auto Parts guy, when asked for the best filter he had for it, recommended a Mobil 1 Extended Performance. Between the two, my low oil pressure at idle seems to have improved noticeably. Still searching for the best filter; anyone used the Mobil 1, and where do you get a Wix?

Thanks!

cruiser54

Wix can be gotten at O'Reilly's, Carquest etc.

drhoward1988

Mobil 1 is a great brand. Even Salad will agree. Wix filters are a great value thoigh. You can get them at O' Reillys or carquest if you have one in your area. I run all mobil 1 myself in many different vechicles. I avg 5-7.5k miles between changes. Ive had the oil tested a few times and it was still good when changed. Shell or Mobil 1 are great choices, but to each their own