Base stocks are just a tool for lubricant formulators, X B Cox, ExxonMobils global base stocks and specialties planning manager told the ICIS Asian Base Oils & Lubricants Conference in Singapore in late June. We live in a period of unprecedented change in the base stock business, with new capacity, rationalization, new players entering the business, changing supply routes and increasing lubricant performance requirements.

ExxonMobil is the worlds largest Group I supplier with nearly 1.8 million metric tons per year of Group I capacity in Western Europe alone. It recently announced changes mirroring industry trends. By 2015 it expects to complete significant expansions of Group II capacity at its Baytown, Texas, U.S. and Singapore refineries.

Base oils make up about 50 percent of direct engine oil production costs, and 75 percent of industrial oils production costs, so a smart base stock choice improves your bottom line, Cox said. In selecting base stocks, blenders must identify limiting technical requirements. They must maximize cost effectiveness by minimizing the number of stocks and tankage, leverage existing product formulations, and select base stock slates for base oil interchange and viscosity grade read across. Finally, they must assess supplier capability.

Engine oils tend to frame the dialogue about base oil selection, Cox continued, but other lubricants are equally important. At present. Group I can be used in about 90 percent of all applications, while Group II can be used in close to 97 percent. Thus a majority of lubricant applications can be blended with Group I or Group II. Group IIIs role is limited to high viscosity index, light viscosity applications, and its still a small segment, despite its oversupply.

Looking at evolving base stock demand through 2030, Cox noted that marine and some industrial formulations will continue to prefer Group I. Premium automotive lubes are moving to Groups II/II+ and III, but there will be very limited use of III+ or polyalphaolefins. The majority of applications can use either Group I or II. On the demand side, the pace of change is expected to be consistent but slow.

Cox cited ExxonMobils base stock slate to show how approved base oil interchange within the slate allows blending the same product with a different base stock mix, without extra testing. Likewise, approved viscosity grade read across within the slate allows blending a range of viscosity grades without extra testing. A well designed slate means you can cover all these products – from 0W to monogrades on the passenger car engine oil side and from 5W to SAE 40 on the heavy duty side – with a slate of four base stocks.

Cox recommended a strategic approach to base stocks. Group I has a long and useful life, and is suitable for most applications. Use it as long as youve got it, and work with your supplier to evaluate long-term supply security. Group II is growing in availability and use. Its important to work with your supplier on when and how to increase Group II use to assure reliable supply and minimize conversion costs.

Group III is in oversupply, Cox noted, with limited applications as trim stock and for low-viscosity engine oils. Group IV continues to be an important niche product; secure long-term supply as needed.

Involve your base stock suppliers in strategic discussions, Cox concluded. You may regret it if you dont.