billyfe390
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- Aug 18, 2003
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Here at work our trucks to include a couple 5.4L's run all day long and never leave the city most of the time it is stop and go traffic with just as much idle time. I run convoy parasynthetic 5w30 made by conklin we change the filters at 2500 miles and the oil at 15000 in gas motors and the diesels run 4000 on the filter and 30000 on the oil. We have been using this for 4 years and havent lost a motor yet. We have periodic oil samples taken and the oil retains 96-99% of its additive qualities.
The main reason you can put extended miles on synthetic/parasynthetic oil is that it doesnt loose its additive/detergent properties like conventional oil does. As long as you change the filter every 2500 or 3000 miles you should be able to run 10k or more on the oil. You can change from conventional to synthetic and back again without harm to the engine or seals. But if you have a new car do not run anything other than conventional oil during the break in period otherwise the rings will not get a chance to seat correctly.
The main reason you can put extended miles on synthetic/parasynthetic oil is that it doesnt loose its additive/detergent properties like conventional oil does. As long as you change the filter every 2500 or 3000 miles you should be able to run 10k or more on the oil. You can change from conventional to synthetic and back again without harm to the engine or seals. But if you have a new car do not run anything other than conventional oil during the break in period otherwise the rings will not get a chance to seat correctly.
Purple Synthetic oil, but after only 1,500 miles I had oil leaking so bad out of the passenger side valve cover...that oil was actually puddling up on my catalytic converter. I changed BACK to Motorcraft 5w30 conventional oil...and ordered a set of valve cover gaskets (thinking I'd replace them at the next oil change), but during the last 1,000 miles the leak has slowed to just a tiny sweat. By my next oil change, I figure the leak will have sealed itself completely. 

So far I've only changed the oil twice at 500 and 3000 miles. I'll be changing every 3K from here on out.