To go with, and not look back is the Q.

[Gray 5.9]

At the time when I went to look at the truck (that I have now) to buy, I ask the owner what kind of oil he had been running, and he said he couldn't remember. He said, whenever they got time to change the oil, his wife would just go to a quick lube change center ! the truck was only used for buisness at his wood work shop and every now and then he would pull his 32ft fishing boat. The day I drove the truck home down the Turnpike, It ran good. When I got home I looked at what needed maintance, and looked at the oil filter which had been on for some time with lots of dirt stains of all kinds. I rubbed off the dirt to see if it had a date on it and it said 103,000 on it!!! At the time It had 124,000 on the odometer. So I went down to Napa and got a wix filter and some Shell Rottela T 15w 40, along with a trans filter and atf+3 fluid. I got back home and pulled the oil plug on the engine and it was pretty nasty, blacker than black. After the I let the crude drain out for an hour, I put the fresh Shell oil in and filled up the new filter also before I put it on. I cranked up the Engine and It sounded even better than before. Ever since I started using Shell Rottela T oil from that day, It has ran better and smoother, no doubt the nasty oil that was in before might have had somthing to do with it running as smooth as it should have in the first place. About a month ago I changed oil in my 85' Honda ATC 250ES Big Red Three Wheeler from 20w50 Valvoline to 15w40 Amsoil for a good test to see a diffrence between mineral oil and synthetic, and noticed a big diffrence in how it starts, runs and I think I might have gained a little more power with it revving smoother, higher and quicker, also being quieter. I have been thinking about switching to Amsoil 15w40 in my Cummins motor, but what I don't like is the thought of not being able to go back to conventional oil. What do you guys think? Should I go for it or just stay where I'm at? Sorry for such a long winded post, THANKS

 

[illflem]

Who said you can't go back? You can switch as much as you want. Biggest advantage I see to syn oil is it's cold weather performance, something you needn't worry about in Florida. I'm using Delo 5-40 synthetic for the first time this winter, so far so good.

 

[Cooker]

Bill's right, you can switch back and forth as much as you wish. IMO, stick with the Rotella and change at max. every 5,000 and keep on trucking. For you next oil change, I would change it sooner than normal. There was probably some sludge built up in the engine from the old oil, and the new oil will help clean some of that off.



BTW - Let it drain for a few hours because the pump will hold oil for a while. This will also help you get absolutley all the dirty old oil out if the engine.



Bill,

I've been wanting to try the Delo 5w40, but I can't find it anywhere around here. How much was it per gallon?

 

[JohnE]

No doubt that fresh oil helped it run better. The injector pump is engine oil lubricated and cooled. Turbos need a good clean oil, too.



If you spend your winters in Florida, then AMSOIL 14W-40 will be great. It has better cold temperature properties than Rotella conventioanl 15W-40 and will better in the summer temps, too. Rotella is good oil. I used it in a Subaru many years ago. That was the only oil that would survive to 3,000 miles. I found later both heads were cracked and the gaskets leaking.



You do want to avoid switching brands frequently. The base stock and additives of different oils are not the same and usually not compatable. I've used a putty knife to scrape the sludge out of the pan of engines where the previous owner's have used the sale oil of the week at oil change time. Hopefully, the previous owners used the same lube shop and the same oil.



Bill;

I'm curious to see how you fare with the Delvac, too. Winter in the Bitterroots got you nervous? I think you've been reading those climate maps too much. Come over here for a visit in January & February for a winter test of the oil.



my 2 reale



-John