You still need to change the filter at the 3000 mark. Oil filters can't hold 5000 miles worth of foreign matter.

 

I used an ac filter, and quaker state 5-30 synthetic. with roslone quart to replace the 6th quart. I have never heard of replacing the filter and not the oil. How do the new units that recomen 5k replacement of filter and oil do it?

 

I use synthetic, and I still change both the oil and filter at roughly 3500 miles. Not going to hurt it by changing the oil too often. Also, it keeps all of the crap out of the engine=longer lasting and better performance.

 

Here we go again. I was under the impression synthetic oil was the justification for extended oil changes. While I'm personally experimenting with a different type of filter(Fram and many others got slammed badly in laboratory testing recently.) and the possibility of extending my oil change to 5k or maybe even 7k, I don't tend towards high revs, muddin, or hard running.

 

I know a guy with a 85' Chevy K10 that he has never once changed the oil in. He bought it new and adds oil when it needs it and changes the filter, but never changes the oil...

It's creeping up on 190k

 

Really? Then I must be out of my mind doing 15 000 on Amsoil. Which is guaranteed to 25 000 miles, btw.

 

I use AMSOIL 0w-30 (severe duty) in all my vehicles with an extended interval AMSOIL filter. Change oil and filter every 20,000.
I work for a police department and we do this with all of our department vehicles as well. Texas Highway Patrol does the same with ALL their vehicles, as a matter of fact we stole the idea from them.
WE nor the THP have ever had an engine failure with this process.

Now be prepared for the price tag, as AMSOIL is not cheap. Bout $110 for an oil change, but it replaces 6 regular oil changes. Use the AMSOIL bypass filter system and you can extend those change intervals a lot longer than 20k.

BTW, I am not an AMSOIL dealer, just sold on the product based on the hundreds of cars I see it work in on a daily basis.

 

I had a 2001 Dodge that I used 10W30 Syntec in and changed oil and filter every 10000 mi. Took that truck to 284000 mi. with no problems. Currently have a 2007 NBS Chevrolet and use the new edge motor oil in it (also 10000 mi. oil & filter changes). I have and will continue to use fram oil filters since I have not had any oil related or any other engine failures in the last 4 years. I usually drive app. 80000 mi. per year.

The Dodge had no engine problems at the time of trade-in.