I know Amsoil people will throw stones at me, but...
I was thinking of using Amsoil for some time. Fortunately, I didn't use it. Why? Because API not only sets minimum requirements but limits excessive amount of additives in oils. Take a look at Amsoil spec sheet. What do you see? A3/B3 rated? No. Even though HTHS satisfies ACEA A3/B3 none of Amsoil XXW-30 oils have this rating (except series 3000). Even 10W-40 does not pass it. I don't even understand how they can market 10w-40 at all for gasoline cars. It doesn't have any friction modifiers. It's like putting motorcycle oil in your car engine. What can we see with Mobil at least 5w-30 and 10w-30 have A5/B5 approval which means that they are long drain capable oil. Amsoil doesn’t even claim A5/B5 capability. So in theory Mobil 1 should last as long as Amsoil if not even longer. I'm not sure if it’s also true in reality. Very high VI in many of Amsoil oils might indicate that they contain more VI-improvers compared to other oils. This can lead to a problem later with ring sticking. If you think that they protect very good as they say on paper read on.
What about Mobil? It seems to satisfy many standards and often taken for industry benchmark. If an oil company wants to compare their oils they always compare them to Mobil. Mobil doesn't need to do so. I think that it indicates that their corporate moral standards are quite high, they don't throw sh*t at other companies. Also it might be an indication that their oils are really the best out there.
This information is gathered from Mobil websites (See references below):
" Red Line Oil talks about "four-ball wear," "load wear," "Falex wear" and "Timken psi load" for their synthetic oil. Are these valid tests?
These tests are low-cost tests generally used to determine the performance properties of grease. They do not correlate with engine performance tests. For example, the use of an additive such as lead naphthenate would yield excellent results in these bench (or lab) tests, but would cause excessive oxidation of an oil in an engine and would cause a motor oil to fail the industry standard oxidation test known as the Sequence III test.
None of the tests referenced are used by API in determining gasoline engine motor oil performance (SL is the current, most severe oil classification), nor are they used by engine manufacturers. The API approval requires the following tests:
L-38 for bearing corrosion.
Sequence IIIF for oxidation, deposits and wear.
Sequence VG for sludge, wear and varnish.
Sequence II for rust.
This slate of tests can cost over $75,000 to run – considerably more than the simple bench tests mentioned.
Red Line Oil claims to have 100 percent polyolester base stocks. Are these different or better than the base stocks used in Mobil 1 with SuperSyn™?
We are very familiar with polyolesters. In fact, we manufacture them and use them in our aviation jet engine oils such as Mobil Jet Oil II® and Mobil Jet Oil 254® and in our refrigeration compressor lubricants, where the polyolesters are utilized for their compatibility with new HFC refrigerants. Polyolesters are indeed excellent at high-temperature oxidation stability and low volatility.
However, our work on automobile engines and jet engine designs has shown that polyalphaolefins (PAOs) offer the best all-around performance for gasoline engines due to their:
Being completely compatible with conventional oils and gasoline engine seals.
Providing both low- and high-temperature performance.
Providing a stable oil in the presence of water and moisture.
Having anti-rust capabilities."
And from Mobil's motorcycle oil website:
" Can I use Mobil 1 15W-50 in my bike, just like I use in my car? Mobil 1 is Mobil 1, right?
Mobil 1 for cars and Mobil 1 for motorcycles are markedly different. Every oil is a balance of benefits. Mobil 1 Tri-Synthetic™ Formula for cars has been developed specifically to satisfy car manufacturers' needs for increased fuel economy and low emissions. That's why new cars come with friction-modified, low-phosphorus 5W-30 motor oil. The low viscosity and the friction modifiers help fuel economy. The low phosphorus levels help protect catalytic converters.
So how is Mobil 1 for passenger cars different from Mobil 1 for motorcycles?
... It's a little hard to generalize about the difference between Mobil 1 passenger-car motor oils and Mobil 1 motorcycle oils. That's because not all viscosities of Mobil 1 passenger-car oils have the same levels of zinc and phosphorus, and there are even greater differences among the three Mobil 1 motorcycle oils. In general, Mobil 1 motorcycle oils have:
Different base stock systems.
Different additive packages.
Different formulations to meet very specific engine requirements.
Okay. Let's start with Mobil 1 MX4T. What does it offer that Mobil 1 for cars doesn't?
Mobil 1 MX4T is designed for sport bikes. Most of these bikes have multi-cylinder/multi-valve engines and use a common sump, which means the engine oil lubricates the engine, transmission and wet clutch. So unlike Mobil 1 for cars, Mobil 1 MX4T has no friction modifiers, which could lead to clutch slippage.
The motorcycle oil also has more phosphorus/zinc for enhanced wear protection at high engine speeds and high loads. Remember, most bikes don’t have catalytic converters, so higher levels of phosphorus are not a problem.
In addition, Mobil 1 MX4T uses different dispersant/detergent technology for better high-temperature performance and engine cleanliness. Mobil 1 MX4T is also offered in a different viscosity grade than Mobil 1 for passenger cars.
[Hmmm... High levels of zinc and phosphorus, no friction modifiers? Seems like Amsoil oil...]
And do you really think that such industry giant as Mobil has less knowledge about motor oils than some basement blenders like Amsoil, Redline, and Royal Purple?
By the way Formula Shell Synthetic motor oil 10w-30 has ACEA A3/B3 rating. If only I could find it here...