Do you recall what the issue was with Mobil1? Seems to me that if it was just dirtier and not causing bushing wear, then it was just doing it's job. Think about it like this, the detergents in the Mobil1 were more effective in getting the inside of the engine cleaner thus dirtier oil. I rather get dirty oil out than clean oil. If the oil comes out clean, then how is it getting rid of the gunk?

 

I would agree. If one brand of oil gets darker faster then another that only proves that the oil has more detergents then then another brand. What makes oil dark is soot from the combustion process as well as any dirt that is making it past the air filter. Normal engine wear from bearings and rings are not going to darken oil alone to notice between normal oil changes. If internal components wear wearing down so quickly they could darken oil in less then 10k miles you would be adding oil monthly to keep up with leaks and burning off oil. If oil sample testing is showing that Mobil 1 needs changing sooner that is not necessarily a bad thing. Again, it might be doing a better job of cleaning out deposits in your engine. What materials were present in the test result at a high enough level to warrant a sooner change?
The harder you drive and/or the more wear the engine has will equate to more blowby and in turn darker oil faster. It is a complete fallacy to claim that you can tell an oil is not protecting your engine as well as another brand by looking at the shade of the oil between oil changes.

It's a proven fact that low detergent oils stay cleaner looking longer because they don't clean the engine as well. It's also a proven fact that just because oil gets dark does not mean it NEEDS to be changed. Anybody who ever owned a diesel can vouch for this.

Mobil 1 is a very well respected oil and is the most common brand recommended by car makers. They would not recommend an inferior product. If Royal Purple or Amsoil truly made a better product why are jet engine manufacturers spec'ing Mobil products for million dollar engines where a failure could kill hundreds of people and cost millions in legal fees?.

At the end of the day ANY name brand oil will work fine in your truck and most likely will never be the cause of the engines final demise. Splitting hairs over which brand of over priced synthetic oil is "better" for a Dodge Ram when conventional oil works just fine only further proves the point of how we as truck guys simply love to be passionate about things that at the end of the day are a waste of time and money. But we do it because it's fun. And that's fine.

If anybody wants to read an unbiased report on oil in general, check this out:

http://www.consumersdigest.com/automotive/motor-oil

 

Nah, the Mobil wasn't any blacker per say, at least that I can remember. It was losing some of it's properties at 5000 miles and some of the contaminants were getting close to the recommended limits where the other two oils showed numbers more consistent with "newer" oil. Not that the Mobil was out of spec, just closer to being out of spec at 5000 miles than the other two, hence the recommendation to change Mobil 1 at 5k and re-test the other two at 7k.


I still have the reports somewhere, will try to find them. Seems to me viscosity was a bit thinner in the Mobil 1 sample and I'm thinking phosphorous, iron and a couple other elements were approaching the upper limits of where they should be where they were pretty much center of the chart on the Royal Purple and Valvoline samples...