First, AMSOIL INC. works closely with major additive companies to select the top-performing, and usually most expensive, passenger car and heavy-duty diesel motor oil additives. These additives have already passed all of the API licensing requirements in a petroleum- or synthetic-based formulation. Then, AMSOIL works with the additive company to maximize the amount of additive used and to boost the additive package in selected performance areas to achieve an optimum performing additive package for the intended application. This is unlike many other oil companies that, because additives are expensive, use the minimum amount of the least expensive additives required to meet the minimum API requirements.
AMSOIL then uses a combination of synthetic base stocks with known performance characteristics as replacements for the petroleum base stocks to optimize performance in areas of lubricity, volatility, viscosity index, oxidation and nitration resistance, pour point, flash point, deposit control, soot handling, emissions and many other areas as well. AMSOIL also uses a high-quality viscosity-index improver with outstanding viscosity and cleanliness properties. This replaces the inexpensive, low-quality viscosity-index improver used in standard API-licensed petroleum formulas. AMSOIL does laboratory bench tests and runs field tests to verify the superiority of the synthetic formula. AMSOIL continues to monitor the performance of the oil through close scrutiny of tens of thousands of oil analysis tests per year across a wide variety of vehicles all around North America and the world. AMSOIL INC. has been collecting used synthetic oil samples from passenger cars since 1982. No other oil company has such a vast database of the performance of synthetic lubricants over extended drain intervals. AMSOIL products and formulations outperform API-licensed oils because they are engineered for top performance from the very beginning.