Good stuff here, lots of oil data. I am going to switch my 00 tahoe 5.3 from a every 3k valvoline and fram life to AMSOIL 0W-30 . Truck has 100k. any thoughts to if this makes since. Any suggestions for the flush?

 

That a lot of miles, the engine can accumulate residue from other oils.

I would recommend using an engine flush or the oil will clean up the residue and be used up to soon. Engine and Transmission Flush

 

Another less invasive method to flush is to use SYN oil for 3K, then change it with a new filter. Removing too much crud too fast with a flush on a high mileage engine could uncover small cracks or deficient gasket seals, which could then potentially leak.

Bear in mind, DYNO oil and SYN oil are compatible, and can be mixed in a pinch.

I would be more concerned with using a top of the line oil-filter, such as K & N. Amsoil filters have all slick surfaces, and no grips for tightening them; and tend to back off, causing a massive oil leak, and all sorts of problems. The K&N oil filter has a six point head on it, which simplifies successful installation and removal.

 

I would not worry about filters backing off, that would only happen if it was installed carelessly. You should never install an oil filter more than hand tight. Using any kind of tool to install an oil filter is a bad idea. You can damage the seal, distort the can and make it very hard to remove later.

Never, never use any tool to tighten a new oil filter, to do so is asking for trouble.

Asbeing concerned with too much crud being removed with a flush, that is not a concern either. If the engine were loaded with too much crud you would likely know about as the engine would be in sorry condition already. If you read the directions for use you see you only run it with the engine idling for 10-15 min, then immediately drain the oil. Let the oil system drain completely then install new oil and filter. That AMSOIL flush is safe to use with every oil change in you were inclined to want to. It does not even require you to use a new oil filter but you could do that if you wanted. It dissolves and disperse all the crud so it is removed easily. Its safe to use as its detergent based, not solvent based.

 

Yeah, well isn't it amazing that the only filter which I installed improperly in 35 years just happened to be the AMSOIL filter?

I find it quite co-incidental that the AMSOIL reps I talked to also seemed very aware of the problem.

And now, of course, that I'm back to using a filter which has a way to properly grip it, the problem has NEVER recurred?

Don't let me stop you, use whatever filter you want. If you are going to use an AMSOIL filter, or any other oil filter with completely smooth, round, slick sides; I would heartily advise you to be sure to GRIP IT TIGHT with a clean, dry, rag or glove while installing it. Also watch it carefully for a few days to make sure it doesn't start spewing oil all over the driveway and the road.

I personally am not going to court disaster by using the only filter which failed me EVER again.

As to engine flushes, there's differing opinions on their effectiveness and usefulness. Not only are DINO and SYN oils compatible,
making a flush unnecessary in the event of a changeover, I've never seen a case where an engine which got regular oil changes benefited from a flush, anyway.

 

Synthetic Oil Update:

The same truck, my venerable 2004- 2500HD-CCLB.

155,000 miles. I've long since switched to Mobil1. Amsoil is OK, but

IME Mobil1 is just as good, easier to find, and about the same price.

I estimate I've easily saved 60% on my oil change costs, overall.

Engine runs like a sewing machine. Generally switch the oil filter at 6000 mile

intervals, topping off with a quart to make up for lost oil in the filter.

Run the engine 24000 miles, with top-offs and 6K filter switches.

Then, at 24K, a complete oil change.

But 2013 was a rough year, and I had a lot of running around, missed

many filter changes, finally when I addressed the oil change,

17000 miles had elapsed, with no filter changes, or anything.

Performed a complete oil change, and back on the road, again.

Some years ago, I was a skeptic about Synthetic Oil. Now, I wish

I had started using it sooner.

I change the oil and filter in my daughter's ION once a year, and it's

done.