I don't even put 1000 miles on my car in a month. If you are driving nearly 1800 miles a month I wouldn't change it every 3K either. I would probably change it every 7500. In my estimation (and it is just that) I think that regular oil changes with quality oil from 3-7500 (depending on what conditions you drive in and the amount of time is the way to go)are just a good idea.
I have a very specific experience with a car with excessive mileage and Mobil 1. But before I tell you that, here is my reasoning in general. Here's my reasoning - an oil change does more than just change the oil. It gives me (or the person changing the oil) the chance to check out everything else on the car. For example lets say I go 10,000 miles without changing the oil and without running a test. How will I know if something else dreadful has happened. What happens if my head gasket starts leaking and I discover coolant in my oil? You say you do the oil analysis and the soot level is still low enough to keep going. Are there other reasons to change the oil besides just soot, what about moisture content, what about tiny bits of metal which every car produces? What about the varnish that forms as a result of oil breaking down? I think of it as insurance. I probably will switch to Mobil 1. I won't change it as early as 3K miles, but for me and my car, that oil is never going close to 10,000 miles. I agree that your driving conditions are much different than mine and that may be a good reason for you to not change it. Ok, here's my story. I told my reasons in general because this is purely anecdotal evidence and the facts are easily distinguishable from your situation. I used to be a Service Manager at a large Oldsmobile/Honda dealership before I joined the dark side and became a lawyer. Anyway, this was 6 years ago. A good customer of mine came with his brand new Aurora. It had less than 500 miles on it. He wanted the oil changed and mobil 1 put in. He even brought the mobil 1 with him. He did this with all of his cars. He had a truck, a corvette, and an 86 300E. Within a few months he and his wife separated, and eventually got a divorce. He continued to come in, but never brought the Aurora. He said that was his wife's car and she could get her own oil changes. I figured she was going to jiffy lube. Anyway, months or maybe even a year later, she shows up at the dealership with her Aurora on the tow truck screaming and yelling about how she was going to sue us and couldn't believe that her Aurora had broken down. Well I had no idea what was wrong, but I started up the car and heard the most awful horrible crashing and banging I had ever heard an engine make. I knew it was bad, but it was under warranty, so I got her a rental car and told her we would figure out what happened. I got the heavy engine to take a look at it. I thought something had happened and crashed the engine. We checked the oil and it was the thickest black tar. It was like thick sorghum. I had the guy raise it up to change the oil. When we pulled the drain plug nothing came out. It was plugged with a gooey thick substance like hot asphalt. We used to screw driver to pry this plug out and the oil begin to clump out in sickening black clumps. I had no idea what happened. We put fresh oil in it and ran it and the engine was toast. The lower end was just gone. When we dismantled the engine everything was covered in this asphalt goop. The engine was not even salvageable. I checked the window sticker and saw that it was our oil change reminder. It said 35XX. The odometer read 23,9XX. She had driven over 20,000 miles on that oil. It cooked it and totaled the engine. I called her and asked if she had the oil changed and she said her husband had that done when she first got the car and she didn't think she had to change it again. Most people don't believe that there are people this stupid, but it is a true story. She never did change the oil. It cost her over $8000 to learn that lesson. Donald Snook 90 300D 2.5 246K Curt wrote: Donald, How much do you drive? I go at least 1650 miles a month just for commuting to work so on 3k oil changes I'd be doing them all the stinking time. My new commute will be at least 1800 miles a month. The other thing is that if the oil isn't worn out theres no point in changing it. If the oil analysis says that the oil is still good at 10k you'd be foolish to take it out just because its "old". There are those who use conventional oil and change it at 2,000 miles "just to be safe" which is foolish and just a waste of money. So tell me why its "Crazy to go 20K on any oil". -Curt
