I wrote that last reply at work, so it was short and I would like to clear it up a bit
we usually change oil every 3000 miles.
that is based on 2 things, the limit of oils in the 40s and 50s, and how much contamination a engine puts out.
I realise that they now say change oil every 5000 now, but that is not for vehicles worked in dirty areas, areas where the ambient temperature is over 85 degrees or vehicles doing a lot of stop and go traffic, basically that is 80 percent of vehicles out there. So it is back to the 3000 mile range.
As far as dirt goes, even with modern detergent oils, we ask more and more out of a modern engine than ever before, so an engine putting out 2 to 3 times the HP that a engine made when our CJs were really need those detergents just to last the 3000 miles between oil changes.
So we can improve the Dino oil with a additive. I think we all have read and chosen a brand of additive, and most are good products. Marvel has been mentioned in this thread, And I also like Lucas, both do as claimed, improve the Dyno oil and help to extend the life of the vehicle, a side benefit is it does not work as hard with the extra polymers. But then we are also
Limited to Dyno oils.
Enter the area of synthetic oils, and here it really gets complicated as there are so many really fantastic synths out there. Two of the big companies are Royal Purple and Amsol, both spoken well of in this thread. If you were to call a SALESMAN from either of these companies they could go through a mured of information expounding the benefits of their product, and recomending different products for different applications till we are amassed and overcome.
So we buy, paying the super premium price for a superior product that we change in 3000 miles.
All that time there is a product that such as Mobile 1 (not the only one, just one I am using as an example) that is as competent as any other for the life of the oil change.
Yes change that oil every 3000 miles, especially if you actually wheel that vehicle, you need to remove all particulates getting into the oil.
but now do we fall under the spell of the super premiums, or go with one of the standards?
I guess it is up to your pocket book. But remember when reading that brochure, or talking to the trained SALESPERSON, that they are spitting out info designed to sell their product over every product they are in competition with.
I invite the other side of the coin to be debated now.