"Our Detriot diesel was using a gallon of oil every three days after a rebuild. The mechanics tore it down and engineers from Detroit Diesel couldn't figure it out. They put it back together - same problem. I went to Eco-Tek and put 1 L of your Super Lubricant and1 L of HD oil stabilizer in the oil and had the driver check it three days later. Oil was right up. I couldn't believe it so I sent my father to verify it. It was true, problem solved! They couldn't believe it. Eco-Tek is going on all my trucks.