Related: Answers to 3 Key Questions on the 2 New Oil Categories
Mack CK-4 Engine Oil Offers Extended Drain Intervals
Mack Trucks has announced that its newly formulated genuine Mack Engine Oil EOS-4.5 will extend engine oil drain intervals for customers.

Photo: Mack Trucks

Mack Trucks announced that its newly formulated genuine Mack Engine Oil EOS-4.5 will extend engine oil drain intervals for customers.
The oil is API CK-4 compliant and is also backward-compatible with all API CJ-4 applications. Mack EOS-4.5 can extend drain intervals by up to 15,000 miles compared with previous formulations, reducing regular customer maintenance costs, accorfing to the OEM.
The oil is factory-fill in Mack 2017 engines, but Mack says that EOS-4.5 also extends drain intervals for all 2011 and newer Mack engines.
“There is a misconception that Mack Engine Oil EOS-4.5 is simply a rebranded version of the other engine oils on the shelf, and nothing could be further from the truth,” said Scott Barraclough, Mack technology product manager. “Mack Engine Oil EOS-4.5 is a proprietary formula that is tested and approved with Mack equipment, which allows us to extend drain intervals.”
With Mack Engine Oil EOS-4.5, drain intervals have been extended to 60,000, 50,000, and 40,000 miles for long-haul, regional-haul, and heavy-haul applications, respectively. During the life of a Mack truck, these extensions allow customers to skip between four and 16 oil drains, according to Mack.
Mack Engine Oil EOS-4.5 is available in 10W30 and 15W40 weights and meets Mack’s stringent EOS-4.5 engine oil standard, which offers protection above and beyond the new API CK-4 specification by requiring enhanced performance for oil oxidation and oil aeration control. It is also formulated with a lower viscosity, helping improve fuel efficiency, said Mack, even under high loads and high ambient temperatures.
More Fuel Smarts

Cummins Adjusts 2027 Engine Rollout After EPA Proposal
The engine maker will gradually introduce its new Model Year 2027 diesel engines while continuing to offer current models during the transition, citing the EPA's proposed emissions rule changes.
Read More →
EPA Proposal Could Ease 2027 Truck Costs and Buying Uncertainty
The proposal doesn't change the tougher NOx standard, but it would revise key implementation requirements that manufacturers say have driven up costs and complicated fleet purchasing decisions.
Read More →
Cummins, Paccar Ease DEF Derates After EPA Guidance
Updated diesel engine software gives truck operators more time to address emissions-system issues while staying compliant with EPA emissions standards.
Read More →
Maintenance in the Messy Middle Part 3: Biodiesel
Biodiesel can reduce emissions, improve fuel-system lubricity and use existing diesel infrastructure. But NACFE’s Messy Middle maintenance report says fleets must actively manage storage, cold-weather operation, filters and oil drain intervals to avoid problems.
Read More →
Enhance Fleet Performance with High-Efficiency Auxiliary Power Units
Drive sustainable cost savings while increasing driver comfort during short- and long-haul logistics operations.
Read More →
Maintenance in the ‘Messy Middle’ Part 2: Renewable Diesel Fuel
NACFE's latest Messy Middle Powertrain Service & Maintenance report says renewable diesel gives fleets an opportunity to reduce carbon emissions without changing trucks, fueling infrastructure or maintenance practices. But technicians still need to understand several important operational differences.
Read More →
The Diesel Engine Enters NACFE’s ‘Messy Middle’
NACFE’s new Messy Middle Powertrain Service & Maintenance report says keeping modern diesel engines running now depends as much on software, diagnostics and data as traditional mechanical service.
Read More →
DTNA Software Update Gives Truckers More Time Before DEF Derates Take Effect
The changes reflect EPA guidance aimed at reducing downtime caused by emissions-system faults while maintaining compliance requirements.
Read More →
New Agentic Predictive Maintenance Report Demonstrates How Degraded Aftertreatment Systems Waste Fuel
Questar analyzed a large mixed-class fleet and discovered it was wasting as much as $30 in fuel per vehicle, per day, because of mechanically degraded aftertreatment systems.
Read More →
New York City's Microhub Project is Delivering Results
Trucking, last-mile delivery companies, and environmental advocates like what they are seeing so far with New York's microhub program.
Read More →
