quote:

a little known secret of many of the quickie lube places – they use recycled oil for the ‘base price’ oil changes.

Didn't know that, scary!

Does anyone know if it is worthwhile getting my diesel oil analyzed and how/where? I hate to just replace it without knowing if it is still very serviceable. any thoughts?

Check with a Cat/Freightliner/Kenworth, etc. dealer. They have kits for pulling any fluid samples that you want tested. Cost is usually $25 or less. First time gives you a baseline to compare the next samples to.

quote:

Originally posted by Shadow man:
Danny, any oil that you put in a filter is better than no oil. The filter on my jeep goes on upside down but i still put some oil in it to fill the baffles so that it takes less time to fill once i fire the engine up. On all of my other rigs i fill the filters as full as i can get them.

You betcha. Any air in an oil filter means a delay to build up to full lubrication.

All filters should be filled before installation. If the filter is upside down, or even sideways, it is best to use a filter that has an anti-drainback valve. All do not. The NAPA Gold filters are made by Wix and the web listing tells if they have the ADB valve or not. Not only does the ADB valve aid pre-filling, but, as the term indicates, it prevents oil from draining out of the filter when the car sits. I had several Slant Sixes with inverted oil filters, and you could really tell the difference. All ADB valves are not created equal, either.

I tested different ones by loosening the filter to check for oil in the filter. Back then, Baldwin had the best one. It held the most oil for the longest time. I don't know if that applies today or not.

Our ancient Toyota has a horizontal aftermarket filter, so ADB is an issue. I am happy with the Mobil 1 filter, so have not checked any others.

quote:

BTW – a little known secret of many of the quickie lube places – they use recycled oil for the ‘base price’ oil changes. Recycled oil can be as good as new if done correctly….but I just don’t have then level of trust with a quickie lube!

It's "re-refined" - and the resulting base stock is generally excellent due to the impurities having been removed. The important element, however in any lubricant is the additive package, and that's a question mark.

quote:

Does anyone know if it is worthwhile getting my diesel oil analyzed and how/where? I hate to just replace it without knowing if it is still very serviceable. any thoughts?

It's not just the analysis, but its interpretation. Frankly, for privately-owned vehicles, it's a waste of money (worse, it could give false assurances). When I was a field rep for Shell, we did (or the customers did) analyses on line-haul tractors. No one bothered with local cartage; they were changed on regular, fairly short, intervals. "Oil's cheaper than metal," I heard somewhere...

Some time ago, a motorcycle magazine did some oil tests. As a joke, they included "re-refined" oil from Pep Boys. To everyone's surprise, it did very well.

I usually change my oil in the bus once a year or every 3000 miles or so. This year i did an oil sample mainly to establish a baseline so i can see how much and what kind of wear i am getting on my engine. Also i can see how my oil is holding up and maybe extend the mileage on it. Some folks say 8-10 thousand miles is no problem. Only thing is for me that would be 2-3 years so i will probably still change on a yearly basis, but if i do happen to go 5-6 thousand miles in one year i will not be so concerned with the amount of miles.

P.S. i have always believed that oil is cheaper than metal.

8-10K miles is reasonable with ULSD. Annually is the maximum interval, assuming that the coach gets a few thousand miles a year.