viscosity index

"Perhaps we should work on the viscosity index next," suggested Data.

The viscosity index can be calculated using the following formula:

Pennsylvania grade crude oil is thermally stable and has a high viscosity index.

Motor oils with higher viscosity indices thin less at these higher temperatures.

Viscosity index is a measure for the change of kinematic viscosity with temperature.

Viscosity Index This determines the change of viscosity with respect to temperature.

The viscosity index is a measure of how much the oil's viscosity changes as temperature changes.

Viscosity index or VI is measure of the temperature at which a lubricating oil works properly.

An advantage over other forms of brake fluid is that silicone has a more stable viscosity index over a wider temperature range.

Thus, although the viscosity still decreases as temperature increases, these synthetic motor oils have a higher viscosity index over the traditional petroleum base.

As stated above, the Viscosity Index highlights how a lubricant's viscosity changes with variations in temperature.

To bring the difference in viscosities closer together, special polymer additives called viscosity index improvers, or VIIs are added to the oil.

Viscosity modifiers make an oil's viscosity higher at elevated temperatures, improving its viscosity index (VI).

A higher viscosity index indicates the viscosity changes less with temperature than a lower viscosity index.

Additives deliver reduced friction and wear, increased viscosity, improved viscosity index, resistance to corrosion and oxidation, aging or contamination, etc.

Viscosity index (VI) marks viscosity change with temperature, with higher VI numbers being more temperature stable.

After a series of processes in order to improve properties of the lubricants, such as viscosity index, pour point, cloud point, the final base lubes are produced and stored.

It's rare, however, that engine oil can do these things without the addition of extra chemicals and the most important of these engine oil additives are viscosity index improvers (VIIs).

A single-grade engine oil, as defined by SAE J300, cannot use a polymeric Viscosity Index Improver (also referred to as Viscosity Modifier) additive.

Group III base stocks have similar characteristics to Group II base stocks, except that Group III base stocks have higher viscosity indexes.

Vegetable oils are attractive alternative base oils for the production of functional fluids due to its high viscosity index, high lubricity, high flash point, low evaporative loss, excellent biodegradability, low toxicity and renewability.

In addition to the viscosity index improvers, motor oil manufacturers often include other additives such as detergents and dispersants to help keep the engine clean by minimizing sludge buildup, corrosion inhibitors, and alkaline additives to neutralize acidic oxidation products of the oil.

It needs to work when the engine is first started and is cold, and keep working when the engine gets very hot, perhaps as much as 200 C. The best oils, with a high viscosity index score, will keep their viscosity the same across the temperature range.

With their improved viscosity index, synthetic oils need lower levels of viscosity index improvers, which are the oil components most vulnerable to thermal and mechanical degradation as the oil ages, and thus they do not degrade as quickly as traditional motor oils.