The conventional wisdom in the lubes industry is that the seal swell component is the characteristic of the breed. They also may or may not be classified the current API-service category, which is arguably not important because the older engines don't require all the features of the latest specs. They usually command premium pricing adding significant motivation for aggressive marketing from the lube companies.
Characterizing HM oils as 'snake oil' is both ignorant and inappopriate for a technical forum.
From a Castrol data sheet, some time ago and my link no longer works, it appeared taht the ZDDP is greater in HM than GTX. Also, VI and viscosities are higher in the HM oils, but the HTHS rate value is worse.
Ok, a "swelling" component sounds good, though i don't know how much such an component really works. Does a HM-engine really benefit from more ZDDP-additives?
ZDDP is also an anti oxidant and corrosion inhibitor as well as anti wear. However, looking at Maxlife the only difference appears to be moly is added and calcium increased.
drwebb
"the older engines don't require all the features of the latest specs".
Anything particular in mind? Looking at US 20W50 oils they appear to be SM ZDDP levels, which may be a concern for older engines (flat tappet).
Are you suggesting that all oils advertised as HM are legitimate. Would you like to buy this nice bridge I have.
The main factors affecting oil life are 1) build up of abrasive particles, 2) engine blow-by gasses forming acid deposits in the oil and 3) heat causing oxidation.
A good filter and detergent additive reduces point 1) buffers or mildly alkaline releasing chemical additives reduces point 2) and extreme pressure and anti wear additives reduce point 3).
The formulation, including oil base stock and these and other additives determines performance, but advertising rarely if ever discloses such information in a quantitative manner, so we are left to decide from buzz words and advertising slogans, some of which are false, misleading or snake oil.
Regards
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No, I do not want to over generalize, which is what I felt ivymike was doing- I appreciate his posts and have come to expect more.
HM oils as a class are generally intended for engines with over 75K of service; most make no claims regarding extended drain and so increased lubricant durability is not a characteristic feature. Is there a misunderstanding of this product class?
Here are the claims for Valvoline MaxLife*:
Helps condition seals and prevent leaks
Helps reduce oil consumption
Helps reduce deposit formation
Helps provide easier cold starts
Is safe for new and rebuilt engines
Note that the first two may be directly related to seals, and most HM products will include similar claims. There are formulation strategies as well as accepted industry standard tests for seal swelling/shrinking, so that is a safe place to start to develop legitimate, customer differentiable benefits for a HM motor oil product.
On this forum we are not completely at the mercy of buzz words and advertising slogans because of the breadth of technical expertise of the membership. And accuracy should be a goal. ‘Snake oil’ is a pejorative term referring to a product that delivers no real benefit and may actually cause harm. That these products have technically differentiable performance and have found a place in the market appears to attest that they deliver a real consumer benefit for at least some portion of the market.
As for ZDDP, the MaxLife product claims API SJ service category, which allows higher phosphorus than the SL or SM oils. Whether this is of benefit to older engines is arguable (without any data) because the SL and SM specs still require passing tests for valve train wear in their engine sequences. Some newer engines also have more stringent cleanliness requirements due to higher-performance design than older engines. Although the current API and ILSAC categories are supposed to be backwards-serviceable, it is becoming more of a stretch as motor oils become more highly developed.
*BTW, I am in no way affiliated with Valvoline or its parent company
I have to admit that I thought the question was about "extended life" oil, rather than oil for vehicles with high mileage. I didn't bother looking for the other thread (still haven't).
It would appear in the US that both Valvoline and Castrol are using low zinc enven in 20W50 oils. The Fuchs Titan GT1 0W20 is zinc free so reducing zinc maybe should not be an issue. However, although the SM tests may in general may be more stringent I'm not convinced re cam wear
SL test
Yes the valve wear sequence tests are different and so not readily comparable- that's where the room for argument is. The Sequence III is a high speed and temp simulation while the Seq. IV is low speed and T. SM reduced BOTH allowable P and Seq. IV cam wear over SL, so the specs predict an SM product may offer better performance around town despite reduced P. Predicting an unused motor oil’s performance based on elelmental analysis is kind of like guessing what a picture will look like from a list of colors on the painter’s palette. The API categories after all are meant only as a one size fits all, fit for purpose minimum standard.
I use HM Castrol in a HM Merc GM with a 4.6 engine. It is my 3rd or 4th Merc GM with that engine. I lose track of how many of these things I have owned. They all have used oil at HM. I started using Castrol HM oil on this one. With standard plain jane oil I had to add a quart at 3K milea and add a quart one thousand miles later to get to 5K miles and was a quart down when I dropped the oil.
I now go all the way to 5K miles without adding oil nor being off the level mark with the Castrol HM oil. Sometimes I'll push it out to 6K, but I'll be about one half quart down at that point.
That is anectdotal and that and one more story just like it wonn't add up to data. Just results.
rmw
PS: recommended it to other HM GM owners and they got the same results.
Are you comparing identical vis grades? A 20W-50 would be expected to reduce consumption over a 10W-40 (and probably a 15W-50) regardless of formulation. That's what I used in my '84 Mercury Crapi in the pre-HM oil days. Ooops, now I'm arguing the other side. But it may even be that HM oils are formulated to the top of the vis grades to reduce consumption while some regular oils target the bottom for fuel economy and cost. Point is there's any number of ways to deliver the product claims, some more sophisticated than others.
