I change mine every 3k, so unless you want to pay for synthetic every 3k, I think the benefits of synthetic are minimal due to the filter's limitations.

There is no doubt that the synthetics are better, a primary reason is because the way it handles heat. Petroleum based oils burn and cause the oil to get that nice dark look. This causes oil coking which is an abrasive and tends to stick to your engine causing the familiar sludge.

Bottom line is you can use regular oils and change every 3k which will work fine, but I run synthetics in everything I own, including my lawn mowers and have never had an oil related problem yet. And if I want to run to 5k on my oil there's no concern of the oil being able to handle it, right along with my motorcraft oil filter which will last longer if the oil stays cleaner.

------------------
69 351W Sportsroof Deluxe

[This message has been edited by Clark (edited 05-11-2001).]

quote:

---

Originally posted by GTRocks:
I read an opinion on this here one time that I have never forgotten: No matter how good the oil that you use is, the impurities are still captured by the filter, and it will need changing.

I change mine every 3k, so unless you want to pay for synthetic every 3k, I think the benefits of synthetic are minimal due to the filter's limitations.

My $.02

---

That was another thing that bothered me; if you leave the oil in for extended periods, you are building up lots of grit and acids. {a byproduct of combustion}

If I switch to synthetic, I will still change the oil at the same intervals.

Just yesterday, I got the part number to a silicone sealer that supposedly holds up to synthetic oils. An engine builder in my area that builds lots of stock car engines had a real hard time getting his motors to seal until a GM engineer told him to use GE RTV100 sealer. He claims this stuff stopped the leaking problem 100% Unfortunately, he says this stuff is hard to come by and you have to buy it by the case in caulking tubes. I'm going to see if that's true.

quote:

---

Originally posted by kid vishus:
I change the Mobil 1 synthetic in my wife's T-bird every 5 miles. I would go a little longer but it sees a lot of town driving.

---

quote:

---

Originally posted by 74merc:
alot of hard runs in those [b]5 miles?
mind sending me some of the $$ you spend on oil? lol[/B]

---

OK, just my $.02, but, the reason I don't use synthetic is, it's pretty much worthless when the engine is cold. The good thing about petrolium based oil is it sticks to everything in the engine, weather or not it is hot or cold. Synthetic on the otherhand is attracted to heat, and will only stick to parts when they're hot. That's the only reason I avoid it, I've tryed it in a couple of cars, including my 84 F-150 and 79 LeSaber bracketracer, both of which ended up NOT liking the synthetic. Switched back to 20-40 in the truck and 10-30 in the car, and never had a problem. You could head ticking and sometimes a nice grinding before the car warmed up :\ So I'm really not a but fan of synthetic personally.

I recommend a blend, or petro, not a big fan of straigh synthetics. I could see for racing purposes running synthetic would be better due to high stress high heat situations, but if you're going to stay on the street, go for a blend or a straight petro

http://members.nbci.com/_XOOM/minimopar/

then click on: "Tech Data"
then scrowl down to: "Engine"
then click on: "Oil Filter Study"
or "Oil Choices"

quote:

---

Originally posted by seaweed:
I would like to here what Alex says about this topic.---What does he use in his engines on the drag strip---street??

---

This was done before in December. Check it out,
https://mustangsandmore.com/ubb/Archives/Archive-000022/HTML/20001224-1-002880.html

quote:

---

Originally posted by horseballz:
Hey Guys,
What about the concept of using synthetic, but spinning on a new filter every 2K or 3K miles? This seems that it would be a good way to take advantage of the longer life of the synth. oil while getting rid of the contaminants.
Alex, what do you think?
((((((((((((((((
Gene

---

Before I get started I use both, 10-30 in the 68, change at 3000 and Mobile 1 in the 98, and change it at 7500.

but...

I used to work in a heavy equipment shop and we maintained, among other things, a fleet of 20 or so stretch vans. They used AMSOIL and the neat filter that they make. That combo is fantastic if you have the under hood room.

We would put 100,000 a year on those vans and the only oil that ever got changed was the stuff you had to replace when you changed the filter. We changed the primary filter every 7500 to 10,000 and the secondary filter every 20,000. After 100,000 miles the stuff still looked brand new. We did have a guy over heat one on the way back from New Orleans after loosing a hose and when we tore the motor down it was spotless. As apposed to the boss who had a olds "cut-less" company car and he swore by Quaker State. We change that junk every 3000 miles and at 60,000 he broke a timing chain. When we took it apart I could not believe the amount of black tar like sludge. You couldn't tell what was what that crap was so thick!

We also used one of those industrial oil analyzer companies for everything, let me tell you, worth every penny. (You don't want to tear down a 15,000 cubic inch diesel unless you have to, trust me on this)

Those vans never had problems. We didn't use the Amsoil in the diesels cause the boss made us use diesel stuff, I believe Rotella T, but I bet they would have lasted a lot longer if we had.

Like I said, I use both, but I have seen many cases where heavily used motors looked brand new inside after over 100,000 miles without EVER changing the oil, except for what you lost when you did a filter change.