today i heard after i got my 6 quarts of royal purple 10w-30...for freethat if you havent used synthetic before and you put synthetic in now....and that i have 90k miles that if i have any rips/leaks that old crud is blocking from leaking...the synthetic will clean the crap and expose any problems that are being masked. is there truth to this? i know that you dont want any problems with the seals and want them to be fixed...but for me id rather not deal with it....let the crud block up leaks and other problems. input would be great.

 

yes, there is SOME truth to that....but more like 190k...not 90k. i'm not a mechanic, just going by what i've read about...not others opinions, oil study type crap. they claim u shouldn't use synthetic until after the initial break-in...the syn. is super slick and won't properly alow for components to seat in a natural way. and like you pointed out, late in an engines life, the syn won't stay built up in tiny cracks. at 90k i wouldn't hesitate switching to syn. then again...if you're happy w/ conventional, it is cheaper.

 

not worried about price really. i dont have to pay for it. when the truck comes in to unload our parts....whenever i need 6 quarts come off and into a bag and out the door into the back seat of my truck. free. i cant say im happy/ un happy with conventional....i would just like to run synthetic. the guy i know from the dealer also said he would recomend switching to synthetic to get some more life out of the parts. hes a friend not the *** hole at the desk trying to get you to spend more money lol. had a guy once tell me from the dealer that in order to fix my truck it would cost over 2 grand to get everything checked out and fixed....turned out it was fu*king spark plugs...

 

great...a f'ing theif.
$2k for plugs sounds about right....after all, they are copper.
i don't know which engine you have....but the hemi takes 7qts of oil.

 

well no....he didnt say it was directly the spark plugs but he wanted to go through all of the functioning parts to see what was wrong....it just so turned out to be the plugs. but i was just seeing what the tech had to say and use his knowledge...after i heard the price i just hung up and started doing things that i thought could be possible factors....started with the plugs and it fixed my problem.

i have a 4.7

 

I heard today... from a service manager.... not to do synthetic until 10K or so because although synthetic stays attached to walls of the engine (specifically if you only drive the truck onlyon weekends like I do) but that factory oil leaks, or perspective leaks... especially in the first few thousand miles.... can be more apparent.... so that in essence synthetics can cause premature leaks....

Thats still my direction...

this guy though has a car Hemi, drives it everyday... and appreciates the $30 oil change vers the $100 variety and only plans on keeping his car a few years

 

Like sa1765 said, full synthetics do tend to clean up some sludge...90k miles isn't that high though. If you really want a clean engine i'd use auto-rx http://www.auto-rx.com/index.htmlbefore putting in RP...auto-rx can only be used with dino oil.

 

well im just gonna drop in a mobil 1 oil filter with some royal purple this weekend. gonna do royal purple in the differential. i got royal purple in my anti freeze too and have noticed a pretty big difference.

 

I'd rather take a ride on the magic bus with marvel mystery oil.
About a 1000 miles before my 7500 mile oil change I'll drain out a quart of amsoil and then pour a quart of mystery oil in the crankcase. and if you got any left over just pour it in the gas tank.

 

what exactly does the marvel mystery oil do?
heard good things about it though