[77newell]

Chester: to the best of my knowledge you are correct.

Clarke: Normal multigrade oils do not meet the specifications defined by Detroit Diesel and there is experience that shows ash buildup in the ring grooves and accelerated wear attributed to inadequate shear viscosity. Since every manufacturer using the same sealing and gasket materials I'm at a loss to explain high leakage rates; high consumption certainly due to the breakdown of the oil's viscosity under shear stress, but not leakage.

My plan is to test the synthetic at the end of the season and once I have the results I suspect it will show that the oil has plenty of life left and I run it for another year. If this turns out to be the case, and I'll report whatever happens, it will cost me less than using single weight oil and there will be less oil to recycle.

I realize that conventional wisdom is that using any oil other than single weight will quickly kill a DD two stroke. Oil technology has changed and unless someone checks it out we will never know what we could have done. So far I'm not seeing the predicted jump in oil consumption, it may even be lower. Still, I'm going to proceed with monitoring and caution.