Sounds like you'd benefit from a synthetic. Stretch the change interval, and it may not be a huge price difference.
-Todd
a frantz filter and a good quality synthetic lube you'd probably be able to run a brand new engine for unlimited miles.
Synthetic oils are not all that "awesome". Synthetics break down just like dino does when repeatedly heated and cooled. This prolonged change interval almost seems like B.S to me sometimes lol.
It's all about proper filtration. Diesel locomotives never change the oil, they just change filters and top up the oil. They are meticulous about oil testing and making sure that it is clean and the additives are OK. Not sure if they even run synthetic.
It's all about the cost:benefit ratio. We have such small oil pans it's not worth the $40 lab fee to check and see the condition when the vehicle only uses $30 worth of Rotella. If you've got a locomotive then the $40 lab fee is peanuts compared to the cost to do a change. Once you're getting in to the 10-15L class the cost of the lab fees and getting another 5000km from the oil versus the cost of a change starts to become economically beneficial.
The Scheaffers oil I run comes with a postage paid container to send your 4 oz sample back to them. If you run their oil the oil analysis is free of charge. No matter how much you want to take a sample. I have sampled mine every 4,000 miles as I was having a soot issue and wanted to track it better. If you run another brand of oil they will do the analysis but they will charge you.
So the cost of the sample for my oil is 0.00 USD shipping included.