I change my oil every 3000 miles irregardless of the manual or what my driver information center tells me. I called a dealer to ask if the 5.3L had hydralic lifters due to a slight ticking when I start my engine. Ticking was no biggie, but in the conversation I mentioned I use Lucas to the mechanic, and he was a mechanic not a service writer. He commented that Lucas tends to gum up engines over time. Now I know this stuff is goowie as hell, and sticks to everything, so it makes sense it could do that, but...... I use half a quart only per oil change, and like I said I change my oil every 3000 on the dot. My oil at 75K still come out looking pretty damn clean. For those experienced GM mechanics, self proclaimed experts,and fellow Lucas users, what do you think? By the way, don't spill that **** in your truck. I had half a bottle leak in my rear door pocket. I still can't get it all from behind the door panel!

 

I'm giving this one a bump

 

I used to use that stuff all the time but I used it sparingly on a 5.0 tbi with 135,000 miles on it. I use an entire bottle in my girlfriend beater (escort) because the engine is pretty worn down. Anyway, I heard horror stories about that stuff gumming up the works (mostly small lines and passages where oil needs to pass). My advice would be to use the synthetic Lucas until your up over 150K and then consider the standard duty Lucas. I still wouldn't use an entire bottle even then unless the engine started feeling tired. Im my 99 i just use Mobil 1 and I'll maybe turn to synthetic Lucas after 100K.

 

The only documentation I have seen on Lucas is it can be so thick that the crank can't pick it up and in large amounts, during high RPM, it will imbed itself with air.

 

Oil frothing/aeration, yeah i can believe that. But it prob isn't as common if mixed correctly. I would difinately ease up on that stuff during winter tho.

 

I'm only using half a bottle, which works out to 1 part lucas to 9 parts oil. Souldn't that mix pretty well into the oil and eventually be thinned out enough to pass through anything. I had half a remaining bottle in a plastic bag sitting in the door pocket of my rear door leak out of the bottle, out of the bag, between the joints of the door panal and down the side of my truck. surely mixed 1 to 9 parts it will go through an engine without issue don't you guy's think? Not to mention I'm religiuos about changing my oil.

 

That stuff sticks to everything. How many miles on your truck?

 

75K. 3000 mile oil comes out pretty freekin clean too. I used 1 quart to 15 in a powerstroke with oil changes every 6k or more, with 225K and no problems.

 

lol, lucky about the clean oil at 3K. I do mine on the nose every 3K with Mobil 1 and it comes out pretty dirty. I have 77K on mine. I guess age? Maybe the difference in blocks? rings? Where I live?

 

Oil all by itself is more than adequate. Full synthetic is best because it maintains it's viscosity over a broad temperature range. If you are changing every 3000 miles and are not generating a lot of heat (pulling heavy loads, racing, etc.), you might consider saving money and use regular old fashioned mineral oil (non-synthetic). Full synthetic is good for 4000 or even 5000. The ads say 7000, but I don't go that far with it. You really don't need any additives, just good clean oil. Any engine that is worn and has a lot of blowby won't last long no matter what kind of magic additive you pour into it, because the oil carbon will eventually build up in the rings and cause them to break. The color of the oil that drains out is not terribly important. It normally means that the detergent feature is working. Of course anytime you overheat the engine (busted radiator hose and all the coolant leaks out, etc.)you should change the oil because the heat breaks it down.