If you are going to be changing your oil every 3750 miles, synthetic is deffinately not worth the expense. One of the advantages of synthetic is the longer change interval.

 

I went to Rotella syn at 50,000. I'll do a change at 7500 mi.<br><br>Mike

 

It took awhile to convince myself to switch to synthetics, but after I have, it's one of those things that I wish I had done sooner. You'll find the biggest opponents to synthetics are the one's that have never used it. <br><br>The reason for the 3750 mile drain interval for conventional petroleum based oil is because it is more prone to breakdown, especially if worked hard. Too many impurities are left in after refining. Synthetics are designed for lubricity, resist degradation, and perform much better at temperature extremes. Drain intervals can be extended, so expense wise, you'll save in the long run. Not to mention, using less foreign, middle eastern crude. <br><br>I plan to performance modify my truck soon by adding larger injectors and a fueling box, and that's another reason why I wanted an advanced lube.

 

So, is oil sampling/testing usually only done with the synthetics because of its longer life?

 

[quote author=Bull Dog link=board=7;threadid=9164;start=15#91177 date=1042384621]<br>So, is oil sampling/testing usually only done with the synthetics because of its longer life?<br>[/quote]<br><br>Yes. It is also done to tell you what kind of wear is happening in the engine.<br><br>Mike