I'll say royal purple again. I use it because out of all the different oils i've tried, it has been the only one that even LOOKED ready for more than 15,000+ when i changed it. Everybody has their #1's, it's all a preference. I use synthetic because its one step closer to our future and with the way oil reserves have been plummeting, alternatives will have to be made eventually.

 

Mine has always been on Mobil Delvac until I found Schaeffers. Changed over and found 1.5-2 mpg!!! Schaeffers is a premium base oil that seals the rings better, so no extra filters are needed, the oil analysis shows you what is going on. It is less expensive that anything close to it in quality. It can be run longer ( with the analysis), withstands more heat, and runs cooler because of the reduced friction.
Anyone should be able to buy it for less than $4.00 a quart. Cheaper in voluume-- by the drum.

 

My Calif owners manual says oil change with filter every 3750 miles. Why so short? I change every 4-5k with stratopore filter, useing delo dino, no problems. I would use a syn type but at this short intervels i don't think I need to. You think MPG would go up with 5-40 syn? I never tow over 8500 lbs.

 

I would say that is their "emmisions excuse". If you go with syn you can go for longer intervals. I can't say about the 5-40, I never tried it.

 

The Dodge manual that came with my new 04,said to change the oil synthetic or dino at the same intervals.Having synthetic does not mean you can go longer between changes.

 

Yeah, if you go strictly by the owners manual. Synthetic oils have been proving themselves capable of longer intervals than dino oil( I say this as per my truck running the comparison; I can see and actually feel the difference when I run my fingers with the used oil). I have found that following the owners manuals strict maintenance schedule cost more money than doing it myself and getting a piece of mind and knowledge. I've also caught ENOUGH ppl ragging on my truck when i get someone else to service it. They just don't respect a persons vehicle anymore.

 

How good is Mobile Delvac it is rated C1-4 and cummins cert!

 

Go over to www.turbodieselregister.com home page and read the results of their oil brand challenge. It's an interesting read.

 

Lookslike I'm changing oils! Thanks for the info!