Originally Posted By: JAG
The market is mostly driven by the oil specifications and many of them can be met with little or no Groups IV and V, so that's what is often chosen for profit reasons.
Bingo!
Generally the marketing folks determine what is needed to maximize sales (approvals. specifications, performance claims, price, etc.), and R&D's job is to meet those marketing targets at minimum cost. There are exceptions, such as when R&D discoveries influence marketing and allow product distinction - then the marketing claims revolve around the new discovery.
Esters are expensive and their use is usually restricted to an "as needed" basis when cost is the primary driver. When performance is the primary driver, esters are used at higher quantities and the oil price is often higher.
The most common "needed" qualities of esters are seal compatibility and additive solubility. These benefits are often not needed in Group III products as the Group III base oils have sufficient polarity to do the job. Other ester benefits like cleanliness, lubricity, and oxidative stability, require higher quantities of the expensive esters, and are reserved for higher priced performance driven oils. For cost driven oils, additives can achieve these attributes to an acceptable degree and at a lower cost without esters.
Esters are produced in high volumes. The high cost comes from the raw materials.
Tom NJ
ps - I am traveling so participation may be limited.