I personally run a mixture of 80% trans and 20% diesel in the summer and more diesel in the winter(50/50). Have been doing this for 3 years now at about 34 gallons of the mix a week. To date ZERO problems a quieter engine and not quiet as good milage. However, if you do the math with what I use, and how much it would cost with just diesel and no mix I am saving a huge chunk of money! Infact we figured it out, and in one year I save enough to pay for a new motor and still have money left over! That is by using the tranny mix though. I know I'm crazy and an idiot to some, but my wallet, a little fatter and happier, just smiles at you!