Issue link: https://read.dmtmag.com/i/53591
SHOPTALK By Tom Jackson If you've purchased a diesel truck anytime since 2007 you need to read your owner's manual very carefully about oil changes B ack in the good old days you changed engine oil every 3,000 miles and that was that. Boy, have times changed. Now most diesel pickups have extended the oil changes out to 5,000 miles in normal service. The caveat is manufacturers have added so much towing and handling capacity to today's pickups that some of them now have stipulations about "severe service." I f your jobs or driving style meet these severe-service criteria – as detailed in the owner's manual – those extended service intervals may not apply. There's also a new layer of technology on diesels manufactured after 2007 that require a new type of engine oil. DON'T BE A SAP The new emissions-compliant diesels since 2007 require lube oils that are low in sulfated ash, phosphorous and sulfur. These are called 6 PROPICKUP February 2012 "low SAPS" oils. Failure to use low SAPS oils will cause your diesel particulate fi lter to fi ll with ash sooner, and cleaning the DPF can be an expensive maintenance item (See "DPF Cleaning" on Propickupmag.com.) Thanks to increased turbocharging and EGR rates, the new engines also run hotter and put more soot into the combustion chamber. To combat this the oil companies developed a new and more robust oil formulation, the American Petroleum Institute's CJ-4 standard. In addition to being low SAPS, CJ-4 oils of- fer better heat and oxidative stability. It's criti- cal you only use oil that has the CJ-4 or higher rating or the engine warranty goes down the drain with the used oil. SYNTHETICS EXTEND SERVICE Better oils and better engines are the reason oil-drain intervals now sit comfortably at 5,000 miles in some situations. But does that mean you can go further than that on full- synthetic or partial-synthetic oils? The moment the automotive OEMs say "yes," we'll say "yes." But for now, they say "no." Synthetics and partial synthetics are supe- rior oils in many ways. The base oil molecules are more uniform in size, thus reducing fric- tion inside the engine. They're also great for lower viscosity for- mulations (such as 5W30), which is essential