viscosity index improver for engine oils: an experimental study

Engine oils are widely used for lubrication purposes in automobile and related industries. viscosity index (vi) improver has found its largest commercial applications as additives to engine oils. examples are power steering fluid, aircraft piston engine oils, modern internalcombustion engines, turbine engine oils (stationary and aircraft), and industrial gear oils. viscosity index improvers are added in the lube oils to reach the desired viscosity index (vi). the enhancement of vi of lube oils (servoneum 100, servopress 68, servomesh sp 220, and servocut 335) by the addition of viscosity index improvers (methylmethacrylate (mma), polybutadiene rubber (pbr), and polyisoprenecis) has been studied. vi of blended oils, made from the lube oils (servoneum 100, servopress 68, servomesh sp 220, and servocut 335) by the addition of mma, pbr, and polyisoprenecis, has shown the potential to reach the maximum value. it has been found that the occurrence of maximum vi depends on the lube oil used and the type and concentration of viscosity index improver.