Q. Why can’t I use a CI-4 Plus truck engine oil in an engine that calls for CJ-4?
A. CJ-4 oils are formulated to provide optimum durability and compatibility for diesel particulate filters. Using CI-4 shortens the service life of the diesel particulate filter. Expect to replace the DPF or a budget for higher maintenance costs and engines manufactured after 2007 require using of CJ-4 oils because they come with DPFs.
Q. If a truck engine oil meets the API category and any other standards set by my engine maker, what’s the difference between that and a premium oil?
This is a complex question, so we’ll give some detail around our answer. Many of the truck engine oil brands have several products in their line that carry the same API credentials as well as engine manufacturer approvals.
Differentiating each performance advantage is confusing.
Here are some things to consider:
- While listed result show an oil with good performance in a particular engine, testing produces different performance results. Qualifying tests of CJ-4 oil vary as much as a fifty percent in allowed vs. the ‘headroom’ performance that a premium additive oil technology get. If the truck owner is concerned about getting a greater service life and optimizing engine life, they might want to get the premium truck engine oil.
- Doing truck fleet testing in true operating conditions is another way to test compliant oil vs. the premium heavy oil. After a series of tests, dismantle and inspect engines at different mileage points.. Tests have shown that the premium oil has much better results.
- Truck owners, ask your supplier what level of performance to expect from the oil you are thinking of buying.