Not all oils are the same. The only way to distinguish them is by comparing data sheets and analyzing the areas listed in the Typical Properties Table (shown on bottom of page).
Viscosity is a measure of an oil's resistance to flow. In practical terms, viscosity is the property which governs oil thickness in an engine. If oil has too low a viscosity (is too thin) there will be increased oil consumption, oil leakage, engine noise, friction and wear. On the other hand, if the viscosity is too high (too thick an oil) there will be problems with starting, increased fuel consumption, reduced power output and impaired engine cooling.
Zinc content is a measure of the amount of zinc dithiophosphate, an anti-wear additive, in the oil. No. 1 is formulated with 100% high thermal stability zinc dithiophosphate, which is less susceptible to chemical breakdown than the zinc additives typically used in gasoline engine oils. All universal diesel/gasoline engine oils (API CF-4 or CE and SF or SG) contain low thermally stable zinc additive. Case IH engineering has determined that high thermally stable zinc is more effective in diesel engines. This change has enabled us to use slightly lower levels of zinc than in the past, and actually improved diesel engine performance.
Sulfated Ash content is an indication of the amount of additives in the oil for detergency, dispersion and acid neutralization. In a gasoline engine a lower ash content is preferable because it minimizes spark plug and valve deposits, and acid is less of a problem than in diesel engines. In most diesel engines, a high ash content is desirable for improved varnish control and acid neutralization. Case No. 1 oil has an ash content of 1.4%, while typical universal oils have ash contents of about 1%.
Viscosity Index (VI) is a measure of the rate of change in viscosity at different temperatures. For an engine oil, a VI of 95 or higher for a straight grade product indicates a quality base stock. A VI above 115 indicates a multigrade oil which contains a polymer to increase viscosity index for an "all seasons" oil.
Cold Crank, borderline pumping temperature, and pour point all relate to the ability of an oil to lubricate during the critical cold start period. The first few minutes can cause more wear than several hours of heavily loaded operation. The lower the numbers the better.
Total Base Number (TBN) is an indication of the acid neutralizing capability of an oil. This is especially important in diesel engines where the sulfur content of the fuel can lead to sulfuric acid corrosion. The higher the TBN, the more protection against acid. As a rule of thumb, TBN should be at least 20 times the sulfur content of the fuel.
