Synthetic Oil

Refer Hauler · Feb 23, 2003

What the general opinion of synthectic oil,
Extended drain intervals?
Have used Rotella for last 20+ years but have a new engine and thought about using synthectics.

Highly recommend the ROHO seat cushion, 3457 miles last week a much needed improvement

Regards

Weave · Feb 23, 2003

I have covered this topic before, and it seems like the folks at Detroit Diesel agree with my opinions on synthetics.
Yes, they have superior lubricating qualities, and much more stable viscosity than standard mineral based oils. However, they are not going to increase your drain intervals, even though the people who make them try to tell you they do.
Most of the stuff that contaminates your oil is from blow-by. It's unburned fuel, water condensate, carbon, etc. (combustion by-products) that get forced past the end gaps in the engine's piston rings. Some of this stuff is heated up and goes out the vent in the form of gasses, other particulates are picked up in the oil filters. But still, over time, things will build up in the oil that are going to just stay. An oil analysis can tell you what they are, even tiny particles of bearing material, for instance. There is NOTHING ANY OIL can do to remove this stuff! You just have to drain and change it. And for this reason, plus the high cost of synthetics, I'd stick with good ol' Rotella.
A good place for synthetics, you ask? Gearboxes! You want them to be lubed well, have stable viscosity, and the oil stays in them for a year or more. Most tranny manufacturers require synthetic lube now.
The higher cost there is worth it.
-Weave-

vernon946 · Feb 25, 2003

Synthetics can improve your cranking speed in real cold weather since they do provide a lower level of friction in your engine. They also help in cold cranking by keeping a thin film on the metal parts so you don't have metal to metal contact, extending engine life.

All that said, the most important factor for your engine is clean oil. If you are following a CAT 3126 around, it is even more important. Your best bet for any medium duty diesel is to add an auxiliary or bypass filter like the big trucks have as standard equipment. This will allow you to extend the drain intervals and keep clean oil to the moving parts.

Vernon

RichM · Feb 25, 2003

I have often wondered why the engine manufactures don!t offer a pre start auxillary oil pump foe medium duty engines.I have seen these pumps offered on the large Cummins engines but not the smaller ones.The way I understand that they work is you have a small 12 volt pump that you turn on and it runs for about a minute bringing oil pressure up and circulating the oil before you start the engine.Seems like this is a good idea to prevent wear. I do use Lucas Oil Stabilzer in my Cummins 8.3 and it seems to help,could be my imagination but the engine seems to be less noisy and the idle rpm is slightly higher,this to me indicates less internal friction.

Weave · Feb 26, 2003

The Lucas oil stabilizer, and others (STP oil treatment, for instance) are sustainers. That is they stick on to the internal engine components and stay there for a while. They have superb lubricating qualities, and eliminate dry start ups. I highly recommend them, esp. when starting in cold climates. But as they are thick, cranking speed will slow a bit, so keep the batteries well charged.
-Weave-

Irishjim · Feb 26, 2003

Weave, Speaking of batteries,what's the best application for deep cycle batteries on expediter trucks.
Thanks, Jim.

Irishjim

vernon946 · Feb 26, 2003

The type of bypass filter I spoke about are the ones that operate while the engine is running by running a small oil flow, usually 10% of the oil pump output, thru a bypass filter.

These are available from sources such as Amsoil and Filtration Solutions in Olathe, KS. They aren't cheap, and neither is a worn-out 3126.

Vernon

Weave · Mar 9, 2003

Unfortunately nobody makes a true "deep cycle" battery anymore. The good ones used to be made for marine applications, such as trolling motors. They were also poplular in big trucks in the 60's and 70's. They were big, heavy batteries that didn't need to be removed and charged all the time. Lots of lead and sulphuric acid, things the Lorax does not like. So the answer as far as trucks has been concerned is just to add more smaller batteries, to make up the difference. The trouble is these smaller batteries deteriorate faster, and are more of a disposal problem than the good deep cyclers of the past were. The smaller jobs are lighter and easier to handle,
and can pump out heaps of current, but they only last 2 to 3 years. A note to van drivers- NEVER keep a lead-acid battery inside the van. I see this has been a popular thing, but it is a dangerous thing.
-Weave-