Convetional 15w40 vs Synthetic?

If the samples are showing get the oil out at 10K, that is what it is. Each motor, the conditions it is operated in, etc determines what is prudent to do. Some get the idea that one size fits all. Even the OEM's adjust their oil change interval recommendations on a number of different factors. Do what works and gives results that you can live with.

 

I would disagree with your contention somewhat. The base oil, be it synthetic or conventional, is not what is capturing anything. It is the additive package that is part of the mix, at least 20%. And they don't necessarily "capture" it so much as it neutralizes it. Those are acidic compounds and the additive package of an oil is what tackles acid build up. And sulfur based acidic compounds are lower anyway as a result of ULSD diesel compared to LSD version, and that also CJ-4 oils have a lower SAPS than CI-4+ and other oils. It takes sulfur to make a sulfuric based acidic component. Even the pre-EGR engines being used today are getting a reduced amount of sulfur thru the fuel and the motor oil. These facts alone have caused some OEM's to extend the recommended drain intervals even on their pre-EGR motors.

And seal longevity is a function of the seal conditioners that are also part of the motor oil additive package, and cleanliness, which is also a function of the add pack. I get the distinct presumption from this and posts from some others, that they really have no appreciation for what makes up a quality motor oil. The base oil is relevant, from a cold flow, required viscosity improvers, and NOACK (burn off rate) standpoint, but it is just a fraction of what is needed to keep a motor running. A motor oil is a team effort from a lot of stuff. All current base oils are bright and clear, conventional or synthetic. Almost like water. The color you see in any motor oil is purely from the additive package. It is an appreciation of what all is going on that has caused me to leave the conventional vs synthetic debate behind me. I am much more concerned with the makeup of the additive package of any oil. Zinc, Phosphorous, Potassium, Moly, Antimony, Calcium, Sodium, Boron and the list goes on of essential components that make up a motor oil. How they are balanced and in what concentrations concerns me more than if the oil is a conventional or synthetic. I just get a blend and get the best of both worlds. Yes, each type of base oil has certain characteristics that are good. Might as well invite everyone to the party.

 

Shell t6 1000 hr drain interval with new oil filter every 500 hrs and samples say I could go longer with my old cat. Cold starting capabilities of this oil are well worth it for me here in northern ontario

 

Well said cowpie1 and right on the money.

 

Where did you get this information? I looked in the book for my DD16 and it RECOMMENDS 10W30, I called Detroit in Altoona and asked if it needed conventional or synthetic blend. They said that either one is fine, and would have no adverse affect on the engine or warranty.

 

Fantastic! Seems like you hit on a great combination!

 

I think you are right. I haven't seen a requirement for syn blend 10w30. Everything I have seen is that they factory fill with 10w30 and then only demand that any oil meet the Detroit 93K218 spec. And there are some 10w30 conventionals that achieve that I think. Safety Kleen is recycled oil and meets the spec for both 10w30 and 15w40 varieties and is on the approved list from Detroit. One could use a 15w40 or 5w40 that would meet the spec. I am sold on syn blends, and Detroit might be also, but I haven't seen anything in their lube manual that states 10w30 syn blend is required. And they list a wide range of oils that meet the 93K218 spec from 15w40, 5w40, 10w30, and 5w30. Since they factory fill with 10w30, and it is recommended, and there are some benefits for cold weather and fuel economy by using a 10w30, I would use one until something proves it is not a good choice.

Here is the DDC 93K218 approved oil list. There are several conventional 10w30's on the list.

http://extranet.detroitdiesel.com/s...lants/Power_Guard_Oils/index4print_93K218.asp

 

Some engine OEMs have different change intervals based on the the oil specs. For example Mercedes had a 500hr change interval for oils that meet MB 228.3 spec if it didn't meet that but met the next lower spec your interval was 250hrs.. At that time most conventional oils didn't meet the spec. and some blended oils barley met it.
So to meet mercedes warrenty requirements you almost had to run synthetic.

 

member: 50844"]Well said cowpie1 and right on the money.[/QUOTE]

Also the additive package spoken of is greatly altered. When on adds some good old Lucas!

 

Also the additive package spoken of is greatly altered. When on adds some good old Lucas![/QUOTE]
If using good quality oil there should be no need for additives. Regardless of being Mineral, synthetic or blend