I have 17500 miles on my 05 KR and am thinking of using a synthetic oil on my next change. I live on TX gulf coast (85-100+ degrees), no heavy hauling,routine driving. I plan on changing oil and both filters at 10,000 mile intervals and both oil filters (factory and oilgaurd) at 5000mile intervals. I would appreciate anyone with experience with these two products ( RP 15W40 or Rotella T 5W40 SYN ) to reply. Thanks, Larry

 

Have been using Rotella synthetic in my 6.0 for two oil changes now. (about 17000 miles on truck total) No problems...best milage lately 19.69 MPG hand calc., empty about 70 mph highway. A little spendy but I figure with this kind of investment it's worth a bit more for synthetic.

Good luck.

JB

 

I switched from Mobil Delvac 1300 to Rotella T, mostly due to availability. Personally, I wouldn't even look at RP.

 

I am running RP and have no complaints. I ran 10,000 the first time and just had it changed and am planning on running 20,000 miles on it. I change the filters every 5,000 miles. The truck doesn't burn any oil between changes.

 

I have researched the Rotella T Synth. and have visited their website and the "bob is the oil guy" website and it is a great oil.

Rotella T - Synth. is CI4+ rated and very well made. It is readily available at Walmart and gives you all the synth protection you need and then some.

Royal Purple may not be CI4+ rated for diesel motors (latest rating) and is pricy.

Good luck on whatever you decide and I would not exceed the 7,500 mile interval for oil & filter changes due to your warranty.

Jeff

 

I've had great luck with plain old Rotella T dino. Cheaper than the synthetic (I run a 2500 mile change interval for other reasons, so I don't really need synthetic) and is also CI4+.

Doesn't help with the wallowed out main bearings though. Oh, wait....thats probably not the oil's fault.