Amazing that with so many responses NO ONE has indicated oil analysis.
Changing oil every 3K is a waste of good money. Here's a few facts I've experienced.
Why NOT to change oil every 3K3K oil change mythI bought a VW and the manual said change every 3K, the European manual of the same car, same engine, same year, same color, same seats, same tires, said to change every 10K miles. Now that if proof right there that the 3K thing " per manufacturer" is a myth. Why does a car sold in Europe get to change at 10K while in the USA it's 3K. Later VW changed that and I think it's 10K now for USA models also.
Now for some fun facts that I personally experience not internet here say. I purchased a lemon from a manufacturer and my case was solid, I knew I would get a new vehicle from them so I vowed NEVER to change the oil on the lemon they sold me. Well, the case wet three years and I drove that vehicle 60K in that three years, and I never changed the fluids. Same original oil filter, obviously I put oil in if it went down, but only 3-4 quarts over that period. She still ran great when I finally turned her back in ( the lemon part had nothing to do with the engine )
I have a Kubota tractor that the last oil change was 15 years ago, and I plough fields with her which is a lot harder than any MH will ever endure.
Lastly there a oil manufacturers that will warranty their oil for 25K.
So my point is, no one on the planet can tell by looking at the oil, or by the miles or hours run on any oil if it's good or not.
If you're skeptical send in an oil sample have it tested, and see how far you can go with the oil you use on that vehicle. You only need to sample it twice. Once at let's say 10K, and if it comes back - good to use, test again at 15K, then you know at least you can go to 15K or back it down to the 10K.
My wife car has 130K miles on it and I've changed the oil 4 times and the car runs as good as the day we bought it, but I do put the best oil they make in it.