Originally Posted By: BrianWC
All of those additives ARE in regular motor oil. This is the reason most folks like Maxlife to begin with. It has higher levels of traditional additives and is typically on the high end of most viscosity spreads. Additionally, Maxlife has a bit of synthetic (group IV, I believe) that prevents burnoff to a degree which is a desireable quality in some high miles engines. Also, the added thickness is a big part of the "slows leaks" claim.
One of the more knowledgable folks can correct me here if I am off base, but I think the main additive it uses in the whole seal department is one that conditions seals and prevents further oxidation of them. I don't think it's something that swells them up vis-a-vis a solvent.
A few years ago, about 7-8 I think, one of the magazines, maybe Popular Mechanics, went to the Valvoline facility in Lexington, KY. Valvoline let/helped them blend a custom motor oil for an experiment/article on the best oil. While they were there the subject of High Mileage oils came up. Valvoline said that about 2 out of every 3 vehicles on American roads had 75,000, or more, miles. If you market a product toward 2/3 of all consumers in that market, that has got to be good marketing.
If you compare MaxLife synthetic blend to Valvoline Durablend, you will see the zinc, phosphorus, calcium, sodium are identical. What you will notice is that MaxLife has an extra add of 300 ppm MolyDTC. I have listened to the arguments about 300ppm as a moly add. Some say at 300 ppm you only have good FM. Some say at 300ppm you have a good FM and a MILD AW.
The Next difference is the base oil viscosity. This is seen in the slightly higher HTHS of MaxLife and the higher 100C cSt of MaxLife. This helps in ring seal, bearing film, and bearing cushion.
Seals conditioners always seem to get the most attention when it comes to High Mileage oil discussions. I can't say anything about anything but MaxLife, synthetic and blend, and Mobil 1 High Mileage. These oils have seal conditioners that actually work to keep seals pliable, rejuvenate, to a lesser degree, dried out seals. I do know that virtually all modern oils need seal conditioners. These are especially needed by oils with gp III and gp IV bases. Even gp II is less solvent than gp I and needs seal conditioners. So, whatever oil you have in your engine has seal conditioners. Where I cannot get a straight, across the table answer, is if High Mileage oils actually have more of these conditioners or if they just make seal conditioners a big advertising/marketing issue. Probably a little of both.
Basically, MaxLife is a heavier oil than the standard 5W/10W-30, has some extra anti wear adds, and comes in both synthetic blend and full synthetic. A lot of folk like to use the oil grade recommended by the manufacturer, but they like the oil to be as close to the high end, heavy duty if you will, as the grade allows. Thus, MaxLife is used in a lot of new engines. Someone said they doubted Valvoline would actually recommend MaxLife for a new engine. Actually, Valvoline has done just that through their tech line, recommending MaxLife as a preventative maintenance, a head start on keeping those High Mileage blues at bay.
Someone also said that if you used full synthetic from the first OCI, which for me is the day I bring the car home from the dealer, you are not going to have the issues that High Mileage oils address, especially seal leaks. I most certainly agree. The seal conditioners that are already present in full synthetic, the cleansing adds and the less creating deposits to be cleansed, the better VI even though it may be a lower viscosity to begin with, all give the full synthetic a great edge. NOW, take all of this and increase the HTHS, and the high temperature viscosity, keep it in the grade range, add some extra FM and AW, and you have a full add pack heavy duty oil. Lots of folk like that in their new engines.
