Diesel Engine Oils & Fuel Additives
Shop Schaeffer diesel engine oils and fuel treatments for pickups, working trucks and equipment. Compare heavy-duty CK-4 oils, light-duty diesel formulations and seasonal additives.
Help choosing a product · Shipping and bulk orders
Buying guide and frequently asked questions
How to choose
Start with the engine’s required viscosity and OEM specification. Heavy-duty CK-4 oil and light-duty dexos D oil serve different applications. For fuel treatment, choose routine fuel care, preventive winter protection or emergency de-gel according to the job; follow the exact product’s dose.
Can every diesel use the same oil?
No. Engine design, emissions equipment and manufacturer requirements determine the right oil. A pickup and a heavy-duty truck may need different specifications.
Are prices per bottle or per case?
Prices apply to the selected package. A 12-quart case contains twelve 1-quart bottles; other packages are labeled separately. Review the package selector on the product page.
Eligible standard orders over $300 ship free to one address in the lower 48 states; orders of $300 or less have a $75 shipping charge. Freight exclusions apply. See our shipping page for pails, bulk packages and quote requirements.
