rrjorg

Is royal purple available at most auto parts? You used to have to order it. Also, whats the general feeling on Castrol Synthetic. Always had good luck with it and the conventional in my earllier years?
Thanks, Jorg

mudmaniac

I recently bought RP at my local AdvanceAuto store, and I also like Castrol.

Sirius018

All are good choices but myself I prefer Lucas Oil and thier HD Oil Stabilizer. The 6.0 in my truck runs better since I have been running it for the past 25,000 miles than it did when I drove it new off the lot in 2004.

mudmaniac

I combined th 2, RP with a bottle of Lucas stabilizer added in my Tahoe.

05silverado

i run royal purple in my 5.3 and i love it

Sirius018

I only started using Lucas Oil b/c my neighbor sells it wholesale and I get it at his cost, anything they make I get at wholesale price.

therewolf

I'm using AMSOIL, which is OK, but their oil filters SUCK.

I can't say for sure from personal experience which synthetic is best, but you shouldn't have a lot of problems changing over. I used to be a "religious 3K change" guy myself, and I'm enjoying not having to go through the mess so often.

Use a good filter you trust, however. Wix, Purolator,RP, K&N. I personally prefer the K&N.

maxxman04

rp is extremely popular in the racing world, as well as general performance. not cheap, but it's one of the best synthetics out there. lucas products are hard to beat. keep in mind tho, switching to synthetic almost requires a full motor flush, and once you start using, you must keep using. mixing conventional and synth. will cause oil to gum up and stick to parts, not good. personally, i run mobil 1, that's what gm quick lube uses, with a delco filter. 5k miles intervals for changing in my duramax and 'hoe, oil always comes out looking clean.

Sirius018

I also use the K&N oil filter.

Ever since I have been using the Lucas and the HD oil stabilizer the oil changes have gone from 3K to 5K and sometimes 7500k miles and the oil doesn't get all black and nasty like the conventional oil.