Direct from Royal Purple:

Can I put Royal Purple into my brand new car?
Yes. Royal Purple currently offers many viscosity grades of API Licensed Motor Oils. To allow for proper break in of the engine, Royal Purple recommends waiting until the manufacturer’s first scheduled oil change or a minimum of 2,000 miles in new gasoline engines. Allow 8,000 to 10,000 miles before using Royal Purple in diesel engines.

I have personally witnessed a bearing destruction test with different oils, and it was extremely difficult to damage a bearing with Royal Purple,even if trying. Any good engine builder knows you have to have a rough cylinder surface to make the rings seat properly.

I agree that the factory uses synthetics sometimes, but how do we know they were not actually bench ran with standard oil. However, based on the above mentioned bearing test, oils with these "super" friction modifiers, such as Royal Purple, have far less friction than just a standard base stock like Mobil 1.

 

Directly from Mobil 1 web site:

Myth: You should break in your engine with conventional oil, then switch to a synthetic oil like Mobil 1.
Reality: You can start using Mobil 1® in new vehicles at any time, even in brand new vehicles. In fact, Mobil 1 is original equipment (it is installed at the factory) in:
Mobil 1 is factory fill in:

Acura RDX
Aston Martin
All Bentley Vehicles
Cadillac CTS, CTS-V, Escalade, XLR, XLR-V, SRX and STS and STS-V
Chevrolet Corvette C6 and Z06
Chevrolet TrailBlazer SS
Chrysler 300C SRT-8
Cobalt SS S/C Coupe
Dodge Caliber SRT-4, Charger SRT-8, and Magnum SRT-8
Jeep Cherokee SRT-8
Mercedes-Benz AMG Vehicles
Mercedes SLR
Mitsubishi Evolution
Pontiac Solstice GXP
All Porsche Vehicles
Saturn Ion Red Line and Saturn Sky Red Line
Viper SRT-10
One of the myths surrounding synthetic oils is that new engines require a break-in period with conventional oil. The fact is, current engine manufacturing technology does not require this break-in period. As indicated by the decisions of the engineers who design the high-performance cars listed above, Mobil 1 can be used starting the day you drive the car off the showroom floor.

 

I personally use Mobil One
and have on and off since 1977
and change it much more often.

But if I had a job
like chief of trucking for Walmart's fleet
and had to look my boss in the eye each quarter
and tell him truthfully that we are using
the most effective "total lifecycle cost"
lubricants available
I would probably be doing what Cummins advises.

For those that missed it in the newspapers
Walmart has made a big deal of publicly pledging
that their 18 wheeler trucks are going to improve from
6 MPG to 12 MPG
as a way of combatting 'Global Warming'

That is a stunning promise.

 

Whatever you put in yuor HEMI, make sure you use only 5W-20 grade, any thicker than that and you could start hearing tack tact tack from the MDS.

Here is a interestign thread..read it completly. CHeck my post so you can get the idea about the grade oil that is very important in these HEMI's and get your own conclusion.

http://www.jeepsunlimited.com/forums...d.php?t=806129

 

wouldnt suggest the use of synthetci in older engines if they didnt start early with it.

otherwise, why not???????

 

I've run mobil1 in my hemi since 1000 miles. No problems whatsoever (not that there should be). I did a lot of research on engine break in, and the majority of new engines seem to have their rings seated in the first 100 miles or so (wish I still had the links so I don't sound like I'm blowing smoke).

 

hehe, the break in period it's s myth nowdays. You just need to let it warm up fully, and then WOT sessions not exactly until red line, but 3/4 way of your red line to "polish" and "break in" your rings almost perfect.

-Diego

 

-exactly the info I found for best break in

 

This stuff is what makes Dealers look STUPID. Guess what, there is no break inand the 5-20 factory fill is a semi-synthetic. Synthetic is better!

 

I've been using nothing but Penzoil Synthetic in my 2003 Ram 4.7L since the day I first changed oil 4 years ago and every time since. I now have75,000+ miles registered. I've done a lot of Interstate driving(80+mph) and a lot of local driving(stop-n-go). IT STILL RUNS PERFECT!