From 5W-20 to 10W-30......

So I am wanting to run the high-zinc oils (Non-Enegry conserving) in my 01 silverado 5.3.

Trouble is, I can only find synthetic 10W-30 (Mobil1 High Mileage) that still has the Zinc wear compounds.

What kind of MPG hit will I take if I go to 10W-30? Have any of you done this? Or does anyone know of a good synthetic 5W-20 that is NOT energy COnserving? :banghead:

just fyi the zinc oil problem only applies to the 1996 and older motors with flat tappet cams! does the 5.3 have roller lifters/cam? i know the 91 4.3 i just sold had a roller cam! you might be worrying about nothing? mike

I have a 1977 Ford 409cid, as well as this chevy 327.....but I dont think the only thing affected is roller cams. The entire rotating assembly needs proper protection. I understand why cars dont last like they used to now :(

I have some advice: DO NOT DO THIS!Put in what is recomended or the lifters will rattle.My neighbor Becky did this and the lifters rattled in a S10 she once had.She did switch back and the lifter quieted right up.Most newer engines are picky what you put in for oil.

here is a link only older flat tappet cams are effected! seems to be rounding some cam lobes on new or reground cams, during breakin. if you are really worried try rotella 5w-40 diesel oil. it has all the additves you need. of course i don't know how 40wt will effect the 5.3, but gm dealers still sell the zinc additive in the bottle to add to energy conserving oil! mike

you have to scroll down! the meat is after all the bull crap!!
http://www.naaaccc.ca/oil_additives_.htm







thnaks mike

Just a heads up, use of anything but energy conserving oils will ruin the cats on your truck due to phosphorus/zinc contamination from non energy conserving oils. This happens from vapors being brought in from the pcv system into the combustion chambers and onwards to the cats. Then it throws all kinds of engine codes.

who needs cats? I am calling local GM dealer, for some additive :)

i like to use royal purple in my 93 silveado with a 350 in it so i would give that a try

Who needs cat converters!!.... With that attitude, no wonder we have global warming from carbon emmisions destroying the planet.

Who needs cat converters!!.... With that attitude, no wonder we have global warming from carbon emmisions destroying the planet.
if you believe in global warming? their are scientists on both sides of the argument! it is a matter of political perspective! i remember when we had global cooling in early 80's. but just for the record my cats are still on! mike

p.s. i don't see what this has to do with silverados?

If they are taking out the additives that the cats were designed to remove, then whats the use?

I just think that no matter what type of cam you have, you bneed to have the ENTIRE rotating assembly proper ly lubricated. Cam lobes are not the only thing to take a beating inside an engine.There is the crank journals, which take a brunt of the energy during combustion.

I want my ZINC!!! LOL

Regardles of the "zinc" thing, stick with the 5-30. About a year after I switched to 10-30 I developed a rod knock that I am sure was caused by not enough oil flow when cold.

I dunno, i just started running Royal Purple in my 04 5.3

Who needs cat converters!!.... With that attitude, no wonder we have global warming from carbon emmisions destroying the planet.

Hate to tell you, but the cats have little effect on global warming, and a 1998 EPA report said they made it worse (not sure what has come of that and don't feel like looking it up). They convert toxic gases to less toxic forms to reduce smog and ground level ozone.

They also decrease the engine efficiency, leading to more fuel being burned, though the effeciancy is far higher than it once was I hear. I don't mean this as a knock on the use of a cat, because they serve a purpose, but like most things there is a trade off and I'm not sure which choice is better personally.