5w-20 vs. 5w-30

[ZSHO]

Lately been using Redline a little bit more expensive but worth it at 46.95 a gallon.The polyol ester basestocks provide excellent high temp stability,much better than petroleums and other synthetics,and keeps upper ring and turbo bearings clean,basically redline oil is for turbo vehicles in mind,together with the motorcraft fl500s oil filter,for warranty purposes the car has been running smoooth and not to many oils out there can be fortified as a true synthetic oil.

[SHOdded]

Do I have to drain some oil out before I put zmax in so I don't overfill the crankcase?

ZMAX claims "it won't overfill the crankcase as it soaks into the metal".  So unless the dealer overfilled at the OC, putting in the ZMAX without draining oil should be ok.
http://www.zmax.com/why/how_to/

[Lanson]

Do I have to drain some oil out before I put zmax in so I don't overfill the crankcase?

ZMAX claims "it won't overfill the crankcase as it soaks into the metal".  So unless the dealer overfilled at the OC, putting in the ZMAX without draining oil should be ok.
http://www.zmax.com/why/how_to/

Yep, it will also not be all that much to start with, we're just talking some ounces not a whole quart.

And yep it does eventually soak into the metal.

I don't like the idea of using it every 6k like it suggests, because clearly that's expensive.  I like doing it once a year or so.  Just a nice way to know carbon buildup and sludge, etc isn't going to be a problem.  Its a very effective "metal cleaner".

I also like using that Royal Purple maxlube in the gas, when its on sale at Walmart or other.  Good value for money for an occasional use product.