One of my neighbors has 90 vette with 103,000 miles on it and claims he has only changed oil 4 times... Amsoil... I understand molecular bonds and lubrication/synthetics oil etc. Need guru input.. during normal combustion process, hydrocarbon burn off and standards of gasoline and hundreds of variables affect oil in the form of acidic reaction on engine parts..His engine has faint rod noise and lifter/valve train noise. Has anyone out their ever gone that far on an oil change???

I have heard that Amsoil can last... but 25k? I wouldn't...

I go about 5k on Mobil 1.

Totally agree Andy! Is Amsoil that good?

I remember a loooooong time ago synthetic oils used to claim 25,000 mile intervals. They don't do that anymore. I think the most I see now is 10-15,000. I think he's asking for trouble.

Matthew

omg wtf

I used Amsoil products in my engine for a long time before my engine rebuild. If I'm not mistaken they recommend changing out the filter every 5,000 miles of the 25k mile interval and topping off the oil by the amount you lost in the filter.
Its been a while since I did that, but think that's the interval I used. Now I'm back to Mobile 1 every 5k like Andy said.

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Only the stupid, Ron. Sounds like something Camero Guy would be up for too.
"Is Amsoil that good?" No. Is Amsoil a good oil, yes, but no better that the other good oils.

That the guys lifters and possibilly rods are a little noisy is not a supprise.

I had a job interview, right after college at Mobil to work in their dyno lab. Didn't get the job but came away impressed with their product. I've used M1 ever since but I don't think it's significantly better than the synthetics from Castrol, Amsoil,etc.

I bought a Chevy van, new, with a 350. I ran M1 with 4.5 - 5k changes for 250,000 miles. It didn't use any oil until it hit 200k and then used only one qt. between changes.

My current p/u, a 2000 Silverado, 5.3 Vortec, has 130k, M1 always at 5,000, uses no oil, no leaks, no noise.

My 92 C4 only has 85k but zero oil usuage, leaks, noise with 4.5k changes of M1.

I also run M1 in the racecar but change it at 8 hours run time (and I build the engines).

Your buddy's running oil a long time is the old "Pay me now or pay me later" thing.

It depends as much on your driving habits and environment as much as the brand. All oils have to pass the ASE certification, even the generic store brands. Synthetics now go for more than they used to, but like everyone else said, not 25K miles. Even factory vehicles are recommending every 10K now. 3,000 mile oil changes are a thing of the past.

I wouldn't necessarily say this guy is lucky, he probably drives like a pansy. Low temps and low revs don't do anythhing to break down the oil, and unless you live on a dirt road it's not getting contaminated very quickly, either.

Of course, all that said, I change the oil in the truck every 3 - 5,000 (she tows 9700 lbs) and the vette about every 100 miles

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One trailer, one racecar and one parts car????

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Come on, Bill, you know the trailer is full of pit babes! 10 slims at 100 lb each = an extra 1,000 lbs.

Plus the kegs, the margarita machine, fireworks, blackjack table...it adds up.

Sometimes I even bring the race car! And 100 lbs of optispark parts.

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The best parties are at the racetrack.

We now return to the origional theme of this thread.

My old pickup has 136K, running Amsoil, at 9K the oil is actually still amber colored and fairly clear. Drive it daily, I think its pretty good. Didn't get Amsoil this time, and put Mobil 1 in, will watch it closely.

AMSOIL stock is Shell oil. They put their magic into it to make it clean etc to last. Regardless, do a Oil Analsys to see if your oil is breaking down after 5k, then 10k. Start with fresh oil, send it off, then after prescribed miles, send some oil in for analysys.
That way you kow what your engine needs are, as everyones are different, especially after a rebuild and the way its used.
My original LT1, from my 93 still had hone marks on it after 110 kmiles or so, forgot the actuall. But the engine was clean and bearings were still good with little marks. So, it was put into another Vette, still running and using no oil.
I used AMSOIL and Mobil only, and changed it every 3500-5000 miles.
Now in my 396, I will change it every 10 kmiles. I also use a quart every 1000-1500 miles now, so it will be close to fresh by change, and the oil wont actually be 10kmiles of use.
Now, My filter ( 1 quart PH8/5?) will be changed every 5 kmiles.