<div class="htmlview paragraph">Refiners have developed a new class of motor oils to meet requirements imposed by the longer intervals between drains now recommended by carmakers. The long-life oil performs far better than the conventional MS oil and, ideally, retains its superior performance features throughout the long drain period. Development of the long-life oil is a milestone in motor-oil technology.</div> <div class="htmlview paragraph">A long-life oil can be designed by relying primarily on three field tests: one which promotes sludge; another rusts; and the third, oxidation. All three field tests provide an opportunity to evaluate antiwear properties. Conditions for laboratory engines can be chosen to simulate the field results.</div>