Mobil Delvac 1300 vs Shell Rotella version 10000

[n5ifi]

I know this has probably been discussed hundreds of times here but I have some observations that I just have to get out of my system. I have been using Diesels since 1983. I've always used Shell Rotella except for a year or so with the first truck where I ran Motorcraft oil. When I purchased my Dodge I found that it too had been run on Rotella. I decided to switch to Mobil Delvac 1300 because I had very successfully run Mobile 1 in my Supercharged Pontiac, Junior Dragsters, Racecars so on and so forth. What I noticed when I switched was that the new oil was as dark as if it had been run 5000 miles after only a few hundred miles of use. I changed the filter. It cleaned up a little and then got dark again after a short time. I changed the oil again. (all this in about 1500 miles) It ran for about 500 miles before it started turning black. I changed the oil again. It has about 1500 miles on it now and it's still clean looking. There has been no noticeable difference in the operation of the truck. (fuel mileage,power ect ect) Has anyone else noticed this? Whats up? Think I'll switch to Delo... ... ... ...

 

[MLee]

This of course is my opinon. (like arm pits , every one has one) you used an other oil, an those additives started to clean your engine of crap that was left behind from the other oil. (Make sence)? I don't think that it would do any harm, just do some cleaning.

Marv.

 

[klenger]

I agree, the new oil is cleaning out the old junk.

 

[n5ifi]

Thats exactly what I thought too. Just wanted to hear it from someone else. This must be why they didn't want people to change brands of oil back in the 70's. I think it was Texaco Havoline or maybe Quaker State that was really bad about solidifying in the engine. When you changed brands to a better oil or oil with lots of detergent it would cause a lot of problems in the engine. (oil pumps ect ect) I've seen engines with drain backs in the heads blocked with sludge from some of those oils solidifying.

 

[Pawpaw]

Originally posted by n5ifi

Thats exactly what I thought too. Just wanted to hear it from someone else. This must be why they didn't want people to change brands of oil back in the 70's. I think it was Texaco Havoline or maybe Quaker State that was really bad about solidifying in the engine. When you changed brands to a better oil or oil with lots of detergent it would cause a lot of problems in the engine. (oil pumps ect ect) I've seen engines with drain backs in the heads blocked with sludge from some of those oils solidifying.

That was Havoline.

 

[RFrisch]

Soooooo..... should i switch from Rotella to Delvac?

 

[n5ifi]

It wasn't my intention to prove one oil superior to the other. I just noticed this strange phenomenon and wondered if anyone else had noticed it too. I wonder what additives Delvac has that Rotella doesn't? One thing I don't like about Rotella is the smell for the first few hundred miles. I haven't missed that at all.