If you’re looking to get the most out of your fleet’s performance, LE’s Monolec Ultra Engine Oil is CK-4-rated, heavy-duty oil that provides exceptional all-season performance for diesel engines. Used by small and large fleets all over the world, it contains shear-resistant viscosity index improvers that provide good viscosity properties at both high and low temperatures and are designed for extended drain intervals. Available in 10W-30 and 15W-40 SAE grades, it increases engine life and provides improved fuel efficiency, rust protection, and wear reduction. Extended drain service can be achieved with periodic filter changes and when using LE’s Xamine Oil Analysis Program. Monolec Ultra Engine Oil exceeds Mack, Cummins, John Deere, Allis-Chalmers, Detroit Diesel, Ford, GM, Chrysler, Caterpillar, and other manufacturers’ requirements; and it is backward compatible for use in older diesel engines.