What is the best oil (synthetic or conventional) that works best in the cummins. the last owner used syntec and FRAM filters is there any thing better? (Rotella, royal pruple etc) what filters work best? is an extra filtration bypass filter a good idea?

 

Everything is better than Fram, if you believe what they tell you Valvoline Premium Blue is factory fill for Cummins, so it's good enough for me Fleetguard filters are the most popular. I run Baldwin fuel and oil filters and have no complaints.

 

I think any of the good quality diesel oils are ok, but all the bad articles I have read about Fram oil filters, I don't see how they are still in business !

 

Definatly fleetguard filters. Oil is personal preference. I would stay away from pennzoil, kinda has the same rap as fram filters, not too good!
ez

 

how about synthetic vs conventional? and what viscosity( I live near Death Valley, our temp range hear is 70F low - 120F high in the summer and 20F low - 85F high in the winter

 

The past two issues of TDR had a really interesting article on various oils.

They took most of the popular brands and assigned them a number. They then anylized them chemically for the level of desirable and not desirable chemicals, compounds, etc.

The end results were not what you would have expected, especially if you believe all the commercials!

Check out those articles.

 

I have a friend who has 850K in his big rig using nothing but Rotella and a Gulf Coast Filter.No oil changes only the filter and add oil lost due to filter change.

 

Any of the big name conventional oils will do fine for Death Valley, they all can handle plenty of heat without coking. Buy on price, they are all good. Sure, some are marginally better in one area or another, but they are all much better than the oil that was originally specified for our engines.

Synthetics really shine when the temp is in the negative range, I only recommend them to folks on the frozen tundra.

 

I use whatever wally world has on sale, Delvac,Rotella, or Delo. Filters are either Wix or Napa (one in the same I believe).

 

Thanks again for the info. Is anyone using remote filter or engine oil coolers? if s what variety?

 

The Cummins has an oil to water oil cooler built in, no need for an external unit.

Several members have bypass systems on their trucks.

 

850k miles and never an oil change? just filter changes?? now come on that's not very believable. that oil in the motor wouldn't be oil it would have the cosistency of mollases in january.

 

The Gulf Coast filter uses a roll of paper towels as the element. Takes about a gallon of make-up oil every filter change. Filter changes are done at 3-5k, so the oil has been changed many times - it's just never been drained.

 

Do I need to do anything speacial to change from synthetic to conv.? (ie castrol syntech 5-50 to rotella 15-40)??

 

Just my personal opinion, but I won't switch any more higher mileage engines over to synth. I always run into some type of problem.

Leaks, loosened deposits getting stuck in hydraulic lifters, ect...

I run Delo or John Deere oil and baldwin filters.

Andy