Synthetic/mobil 1- Oil Analysis Data

[99lsguy]

Hey guys,

Saw this web sight. As an avid Amsoil Synthetic user, the test caught my attention.

I know many of you use Mobil 1 so here's a technical analysis:

http://neptune.spacebears.com/cars/stories/mobil1.html

The biggest point it makes is how well the oil will stand up with only a filter change and 'top off' the oil...and how little engine wear is after the 3k mark.

[SRK]

Although Mobil made claims about increased drain intervals in the early days, they no longer do, and recommend changes, with filter, at the manufacturers intervals, or shorter.

Measuring TBN is next to useless. They provide no usable definition of it, and appear not to understand the base number. It is an esoteric measurement in any event.

Wear metals are not the only measure of an oils suitability for extended use. More important is the detergent dispersant behaviour at the drain point. If the oil is in service too long the d-d's are depleted, and the resultant piston ring deposits are very harmful to the life of the engine. Determining the amount of deposit requires dismantling the engine, something most people are unwilling to undertake, or unaware of.

The suitability of the additive package in preventing excessive deposit or contamination on the O2 sensor and the catalytic converter, and the amount of crankcase gases vented to the intake system, and their influence on engine emission performance, is not mentioned at all. Extended drain intervals are very harmfull in all of these performance indicators.

I will continue to trust the American Petroleum Institute, the Society of Automotive Engineers, and the International Lubrication Standardization Advisory Committee's testing and rating of engine oil performance, and not some backyarder's idea of what constitutes a good engine oil.

[99lsguy]

SRK,

What are your thoughts on Amsoils claims of 25K per interval with one filter change at 12.5K.

They usually cite Diesel Tractors and even give examples of 400,000 miles while using "bypass filters" ...........

[SRK]

I am not a fan of extended drain intervals at all. Consider how much money you will spend in gasoline to wear out the engine oil in 5-6k miles. Gasoline costs far more, and yet the oil determines the engines life. Saving the engine is more important to me, than saving money on the oil.

A pal of mine works for one of the biggest tanker truck fleets here in Canada. The engines in the Freightliners and other tractors cost $50-60k. To maintain the warranty, the oil is changed at the recommended interval. With the new cooled-EGR diesels, oil changes are essential because of the soot loading that occurs. The soot particles pass right through any filter, and will gel the oil at a certain concentration. The oil has to be changed.

The bottom line for me is that oil does much more than lubricate, and filters do only one thing - remove particles down to a certain size. Filters do not change the chemistry of the oil, and it is that chemistry which is so important to all of the functions that engine oil must provide.

[93LSOwner]

Well, since we are on the topic of synthetic oil. I will put what ever you guys suggest, then what a local machanic tells me too; since you guys are the experts of Lexus. What is the right oil to put in a 1993 LS400 with 146,000.

[99lsguy]

My opinion is a 5-30W synthetic. Best for cold starts in winter and keeps engine cooler in summer; superior in all aspects to dino oil. That being said, dino oil is still good enough .

Lots of guys with Gen I LS use Mobil One and change every 5K.

Some will argue that heavier weight is better for older LS's;

I think you can get 300K+ with dino oil....my 4 cylinder Hondas' always got to 225K before biting the dust......

[K9crew]

I have to admit that I'm not a big fan of extended oil change intervals either (for my personal vehicles that is) since oil is cheap and my labor is free. But if I owned or operated a fleet of 50 trucks, each of which required 30 QT oil changes every month I would certainly be looking at ways to extend the life of the oil. Bypass filters that filter down to around 3 microns in combination with a good synthetic oil like Amsoil that is less susceptible to thermal breakdown go a long way to reducing downtime and reducing costs. If my fleet is producing 1500 QTS of waste oil each month that needs to be properly disposed of then that's going to cost some money in addition to the cost of paying someone to change the oil. Extended oil changes certainly have their place but I don't think that our cars are in need of them. A good oil, dyno or synthetic in combination with a good filter are all that's needed.

:)

[SRK]

Interestingly enough, we are now seeing the beginning of the end for dino oils in automotive factory fill. Presently, all LS-1 and LS-4 Corvette engines are factory filled with 5W-30 Mobil 1 synthetic, and that viscosity, and an oil specifically approved, must be maintained to keep the warranty. I believe only Mobil 1 is presently approved. Jaguar, Aston Martin, Porsche, and AMG modified Mercedes Benz engines are also all filled with Mobil 1 0W-40 or 15W-50 to maintain warranty. BMW M-series engines are also factory filled with a German made synthetic, and no other oil can be substituted, or is approved.

Within a few more years most cars will have synthetic oils, or more highly refined and hydro-treated dino oils (which border on synthetic in quality) as a factory requirement. Meeting ever more stringent emissions specs, and dealing with increasing temperatures will demand synthetics.

Nonetheless, modern dino oils are outstanding, especially compared with oils of only ten years ago.