By utilizing high quality performance additives, DURAFLOW Heavy Duty CJ-4/SN 15W-40 Motor Oil has received formal API CJ-4 licensing. The product excels when compared to lower grade diesel engine oil offerings in the following ways:

  • Excellent TBN retention when compared to alternative detergent chemistries. This is demonstrated by a lab simulation using sulfuric acid which mimics contamination formed in an engine during a drain cycle. With this simulation it can been seen that calcium based detergent packages control more acidic by products than similar TBN values using magnesium based chemistries.


  • Excellent oxidative and thermal stability.
  • Superior protection against sludge and varnish formation.