I'm no expert, but as far as running the synthetic about 10k-15k, even if the oil lasts that long but the filter wont, you can change the filter with out changing your oil i think. You can just punch a hole in the filter, drain the little bit of oil out that was in the filter, put the new filter on and check your level. Filters are cheap and easy to change, so run the oil as long as you feel good about runnin it.

 

When you buy synthetic oil you also get a filter that is designed to past as long as the oil. That way you don't have that problem of the filter not lasting enough.

 

Yeah, i'm not sure the best filters out there can last anywhere near 10-15k tho or i wouldn't leave an oil filter on anywhere past 5000k, even with synthetic at the longest. I was just saying it isn't difficult to change your filter in between the oil changes. Maybe it's overkill, idk, but i sure would feel better.

 

amsoil eao is -182k trouble free miles changing 1x 25k intervals, just changed for 7th time at 175k- zero issues-on my van, do this on all my company vans-10-[04-10's] over 1 million documnented trouble free miles, i put that money from 3k mile oil changes towards my employees eoy bonuses

 

Thanks openclass...I can't believe this thread made it this far with no mention of Amsoil!! As stated, Amsoil EaO filters are the only filters I know of fully rated and guaranteed for the 25,000 mile life of the oil. They are the best constructed quality filter I've ever seen too. Mobil 1 filters are pretty awesome as well, but I don't know the recommended mileage on those. I will give you my personal input on this for what it's worth...If I were going to exceed 5,000 on an oil change, it would absolutely only be with a M1 or Amsoil filter. Up to or over 10,000, nothing but the Amsoil.

Synthetic benefits also include a significant increase in heat capabilities and viscosity stability. Towing, high RPMs, etc, really drive up the temp. Synthetics hold up much much better. And then there's the significant cost savings that a lot of people refuse to take advantage of.

(I lack the technical terminology mumbo-jumbo to transferr this data, so bear with me...) The big thing with changing conventional oil (and even some blends) so often is viscosity breakdown (not sure if breakdown is the proper word, but??), and not so much the dirt. In simple terms, after X amount of miles, your 5W20 just isn't a 20 weight any longer. With a true synthetic, and especially a PAO like Amsoil (and most likely RP) that doesn't happen near as often. Thus the main reason you can extend out the change intervals so long.

 

As long as trucks roam the earth, the oil debate will continue! Good info here. I have been using Royal Purple for some time and recently have gone all-Amsoil. If you become a preferred customer (I think it's $20/yr for this) you can get their products for a GREAT price. I just had my tranny flushed with Amsoil ATF yesterday and I immediately noticed a difference. Shifting was tighter, acceleration improved... I'm sold that their products really are a step ahead of the rest & worth the price, especially when you consider how much longer they last.

 

I'm going to emphasize - if you plan on extending your oil change interval past factory recommendation by using synthetic oil designed for that, use a premium filter designed for extended intervals too. I use Mobil 1 EP and a Mobil 1 filter, and run it to between 8 and 10k.

 

I'm def going with the amsoil filter when it's time then!

 

Really no need to change to these higher cost oils.
They won't buy you anything over Motorcraft 5w20 blend that is the original spec oil.
Changed at about 7500 miles along with the filter gets you the same protection or better just from the change interval at about a cost of $15 including the filter from a WalMart.
The 5 weight is the fast cold temperature startup protection and the 20 weight is the hot running protection.
No matter what you decide to do, do not use heavier oil weights thinking it is good for a high mileage motor.
Remember that these motors use oil pressure operated hydraulic cam chain tensioners.
They will wear faster under cold starts with heavier oil weights due to higher pressures during cold starts and warm up of the cold oil.
This is where the 5 weight becomes of value.
Also consider that extending oil change intervals will allow the oil to get heavier in weight.
It dosen't stay in new condition for very long especially in an older motor with more contamination products getting by the rings.
Extending the change interval only make it worse.
The filter does not change this issue.

 

Ah man, you were doing so good right up until this point. Oil viscosity does not increase over the course of mileage. Quite the contrary, viscosity (weight) decreases with time/mileage. These "high mileage" oils that you say offer no benefit are designed to provide the viscosity stability over the long haul that conventional oils can't. Especially PAO and other extended interval oils have additive packages that enable them to maintain their viscosity over these longer durations where conventional and non-PAO synthetics can't. No benefit to expensive, extended interval oils like Amsoil?? True, if you're gonna change the oil every 5,000 miles anyways and not take advantage of the oils capabilities.

 

extending oil interval makes it worse?,lol,c my earlier post

 

There isn't an oil out there that will last 3000 miles if you don't give it time to cook properly, - period. Funny how know one bothers to post anything about that. Short trips can contaminate oil pretty fast in cold climate situations, not one of them can magically transform moisture/water into anything good for your engine if it isn't given the time it takes to rid itself of said contaminants.

So I can't cook...

 

I just do Motorcraft 5W-20 Full Synthetic and the FL-400S filter every 5K miles

 

10-15K on royal purple? what in the world?


i change my rp every 3000. i dont trust anything longer than that.

granted i only drive like 4000 a year

 

If you change every 3k, you are wasting your $$$ on RP. I'd use the cheapest 5W20 oil that meets specs and a Motorcraft filter.