"Where does the advice to change oil every 3,000 miles or 3 months come from? It doesn't make sense to me why people would still being changing oil so frequently when there are options out there that are rated for 25,000 miles (or 1 year)."The number 3,000 is one that has been associated with oil changes for decades and decades, back when you could change your own oil and not have to worry about resetting some computer so it stops giving you a digital message.
Engines are made of metal which must move in a beautifully orchestrated fashion to work efficiently. Metal rubbing against metal causes friction which results in heat. Heat expands metal causing the pieces to not fit quite right and therefore not work quite right. Lubrication in engines -- like so many other parts of life -- is essential to the system remaining functional. Over time, the oil becomes contaminated with impurities it picks up and it breaks down chemically, making it less effective at eliminating friction, so it and its corresponding filter need to be changed. 3,000 miles was the generally accepted number for engines and oil as they were manufactured before modern innovation. Now, we have better lubricants that resist heat better. We have engines that are made tighter and are self-monitoring for some of the issues you were looking to avoid. As such, 3,000 miles is unnecessary.
Why is it still automotive gospel? First, once a belief is widespread, it is accepted and difficult to change even when change is rational. Second, the more often you change the oil, the more oil is sold. I know it is hard to believe that oil companies and car dealerships would be less than honest and open, but...
"What is an objective assessment of the risk/reward of the fracking process as in North East PA?"This is a hard fracking question. When we need information that is more technical than we ourselves can determine, we have to rely on authorities. a legitimate argument from authority has to satisfy three criteria: (1) the authority must have actual material existence in this universe (no "I read somewhere that..."), (2) the authority must be a person whom we have good reason to believe knows the answer (the person is an actual authority in the field), and (3) the person must not have a personal interest in getting me to believe one way or the other. The worries in the fracking case is with both (2) and (3).
Consider them in opposite order. There is A LOT of money at stake here and powerful corporate interests that want access to the shale. They know that environmental concerns are real and playing off of the tobacco and industrial chemical industries' experiences, they know how to buy scientists and infiltrate the literature to plant information they can use in court and in public relations efforts to sell the project. They've bought, for example, the geology department at Penn State which is now an arm of their marketing departments. An objective assessment would have to be one that is not paid for by the industry. It would have to be transparent in its assumptions and methodology and have its findings replicated by other independent sources. The problem is that those producing the studies want to keep that information hidden. Case in point,
A New York Post editorial advocated for New Yorkers to "frack, baby, frack!" citing a "new study out of Penn State" claiming ample economic rewards of natural gas drilling in Pennsylvania. However, the editorial failed to note that the study was sponsored by a lobbying group representing gas companies.Then we have the problems with (2). Who are the experts here? It is what we call an interdisciplinary problem. There is no one set of experts to turn to and working across intellectual boundaries in a way that allows a unified account is difficult.
But it is even trickier in this case because we are dealing with a process whose real effects are as of yet unknown. There have been an unusual number of earthquakes in regions of Arkansas and Virginia where fracking has been taking place. Are they related? Maybe. We don't know. The unintended unforeseen consequences of something like this cannot be predicted -- that's the unforeseen part -- so a cost/benefit analysis could be way off should there be huge unforeseen costs.
The answer then, is "heck if I know." Issues like this require rational decisions based on our best models of the costs and benefits and these models are always and necessarily based on incomplete information. But in this case, we seem to have some glaringly big question marks and we have to hope the frack that the worst case scenario doesn't come to be.