Anyone out there use Amsoil in their Power Stroke ? I was going to, and a mechanic at a local dealer told me that synthetic oil will cause leaks to develop on the Power Stroke, and is not recomended by Ford. I currently have 82,000 Miles on my 99 F350 CC DRW and have always used Mobile Delvac 1300.

 

Find a new mechanic. There is a grain of truth in what he says, but not much more than that. At one time, when tolerances were held in the thousandths of an inch, there were lots of little areas where oil could weep out of even a new engine, and run out of a well worn engine. But as luck would have it, the use of petroleum based oils in these engines, associated with heat which every engine produces, would develop a coat of "varnish which would keep the engines remarkably oil tight.
Synthetic oils, however, have detergent qualities that will dissolve that varnish and cause those engines to start losing oil, some of them dramatically so. But with todays machines and their ability to hold tolerances in the ten thousandths of an inch, along with selective assembly, and much higher quality finishes on all surfaces, engines tend to be and to stay oil tight. I would doubt (although I can't guarantee it) that 82,000 miles has put sufficient wear on your high quality engine to create this situation.
I have been using Amsoil full synthetic oil, along with their dual remote bypass filter since 5,000 miles. Now at 41,000 miles, I have only had one oil change since. I send a sample to Blackstone Laboratory every 5000 miles, but after the last sample they advised me that the readings were sufficiently stable that I should feel comfortable in only sending samples at 10,000 mile intervals.
Swithcing to synthetic will give your engine superior lubrication, especially on start up and superior thermal protection, as it offers adequate lubrication at temperatures that would have petroleum based oils turning to charcoal. This can be especially important in our turbos, as we all know, they get hot and shutting them down while they are too hot can lead to turbo bearing failure. Other than initial price, synthetics have nothing but advantages. And if you go to extended drain intervals with regular oil analysis, they can even compete in the price category as well.
So, as I said, find another mechanic that is up to date on his wives' tales.

 

There is truth to the fact that Amsoil is not recommended by Ford. It isn't API certified and Ford specifically states to use oil with a certain API certification label on the container. Amsoil skirts this issue with various answers, but the bottom line is that it is not API certified.

Using any synthetic oil on a higher mileage engine can cause leaks to develop. By this point the seals have deteriorated to some extent and the greater lubricating ability of synthetic oil will find the small openings that a dino oil won't. It doesn't cause leaks to form, it just finds existing leaks that dino oil won't go through.

 

i am not a big fan of amsoil its cost me to mush in parts at the track and burnt to many gears,rearends and many more parts its just cant hold up to the heat. i dont run it anymore

 

I have a lot of miles (over 100k) on synthetic engine oil, and no leaks... I have 6,000 on amsoil, with no problems.

Theo

 

that may be great but when it cost over 3200 bucks for a new rear end no counting ring gears,bearings,quick change gears,seals,pumps,filters,oil coolers and the braided lines it ruined. i dont think that it is a so called great product. it may be for street cars but not for what they would like it to be

 

So what does oil analysis cost?

I don't mind if a little oil leaks out of an engine. Heck the airplanes at work leak like a rusted out bucket but there just fine.