LightMan, I have never had any oil checked by a lab... how does that work in terms of YOU... do you run the oil , lets say, 3/4 ths of the distance you think it should last,,, and send in the sample ? or half the distance...? If you wait the full distance... and if it checks out still "good" whatever criteria you choose for that....do you keep driving it and send in another test sample ?

Seems to me that $ 14 would go a long way towards just changing out the oil.... always the safe bet... ?? particularly if it might include two checks on one batch... Enlighten me LightMan.. Thanks, Greg