Reading the AMSOIL website it states that one can go 25k miles before an oil change. My question is how long are FILTERS supposed to last? Would it matter that you can wait 10, 15, or even 20k miles on the oil if the filter still needs to be replaced every 3k miles? Anyone that uses AMSOIL actually not change their oil for this period of time?

 

That is the most retarted thing for an oil manufacturer to say. For two reasons:

1) A lot of what you are getting rid of when you change oil is buildups of fuel vapor and condesation in your crankcase. No matter what oil you use, this does not change.

2) The whole point of using synthetic oil is to keep your engine cleaner and in better shape, running it until it is just as broken down as normal oil defeats the whole purpose

I am a strong proponent of synthetic, and it is all I use. I personally will not go over 4500 - 5000 miles, and that is pushing it, between oil changes. It is better to over do than under do.

Don't get me wrong, I am not arguing with you one bit, just warning you about the oil makers claims. And I know that I am opening a can of worms, cause a lot of guys will start yelling back about "these are new engines, new oil, new technology ", but my engines last incredibly long, and my oil always looks suprisingly clean with the way I change it. I have worked on the inside of some sludged up motors due to not changing oil until every 10,000 miles like the oil bottle said to. And the same oil company will tell you to still change the filter every 5000. Now if the engine is still producing enough crap to need to change the filter that early then the same crap is elsewhere in your oil. So they are pretty much telling you they are full of it. And hey, I am still getting more mileage between changes than if I used regular oil, so the cost is no big deal. I feel that it is very very cheap insurance to my engine.

Anyway, thats my speel... sorry to make it so long...... just wear it out due to driving like a bat outta hell instead of sludgey oil

 

Well, I only ask because I DO drive heavily. My last car before I wrecked her was at 127k and it was only 4 years and some change. I already put 3.5k on my tC in one month. On the TT I would get my oil changed every 5k or so like Audi asked...have no clue what oil they used. I plan to do my own changes so I know my car better so I had questions. I am using Mobil 1 synthetic, but curious about others. At least I hear Toyota engines go high miles!

 

I use full synthetic, and change it every 2.5-3K miles.
But I dog the hell out of my engine and feel better safe than sorry.

I refuse to use the dealer after they A> scratched both my drivers and passengers side rear doors (and they never fixed it). and B> they used 10W40 oil instead of 5W30.

 

Amsoil does state you can go up to 25k w/out an oil change. It is a good oil, but no matter how good the oil, I would still change it between 3-5k miles.(3k for me) At my shop I have a customer who uses Amsoil in allll of his cars. He actually is freinds of the owner/founder and current owner of Amsoil, and gets the oil wholesale shipped to our shop. For those of who want to know, its around $75 for 12 quarts.

Its funny how oil change threads get sooo long, and at the same time its funny how many people do not take it seriously. I heard from my VW buddy that Audi/VW have sludge problems, so they strongly recommend to change the oil around 3-5k miles. Toyota also has sludge problems, as from what I hear some dealers tell there customers to change at 7500 mile intervals.

 

Amsoil does SAY that you can go 25K, BUT, that is after changing the filter at 12,500 and topping off the oil. ALSO, they highly reccomend that you send a sample of your crankcase oil every few thousand miles for analysis. Then they will tell you whether to keep going or change. Oh yes, they also require you to use their full bypass filtration system (aLOT of extra plumbing and new filter cartridges!)
This system/approach is used quite frequently by over the road truckers and some claim 100's of thousands of miles between changes. Of course, these guys are used to putting a million miles or more on them big diesels before overhaul!!
I for one will be changing my Amsoil every 4-6K. Oil is CHEAP, even at 6.00 per qt!!

Walt

 

Exactly! The main reason for changing oil is to get rid of all those combustion byproducts building up in your crank case and oil pan. Whether you use conventional or synthetic oil makes no difference. Synthetic oil may take longer to break down but that doesn't matter since crap is still building up in the oil. Change your oil every 3k miles, period.

 

Castrol Syntec 5W30 with Fram Tough Guard filter.