I have been a Mobil 1 oil user for years. I belong to a couple of car clubs and at tech sessions I have heard all of the reasons from experts on why a synthetic oil is better for an engine.  But it wasn't until I bought a new turbo charged Audi that I found out that the right oil is vital to the longevity of your engine and the all important turbo charger.Since I do my own oil changes, I always read the owner's manual for maintenance tips. Because my Audi was the first car I have ever owned with a turbo, I made sure to read the oil section carefully. Audi (and parent VW) are so big that they can specify the characteristics their engines require to oil manufacturers. Almost always, this spec is spelled out in the manual and Mobil 1 will place it right on the bottle (in my case, the spec is VW 502.00).Modern engines are very high tech with tight clearances and technology that delivers, compared to just a few years ago, superior performance. And yet they are relatively non-polluting. Also, they are engineered to deliver good fuel mileage. This oil makes it on all counts.I urge you to crack the owner's manual and look at what your car's manufacturer recommends in terms of viscosity (that's the 0W-40 part), what type of oil works best (e.g., synthetic or not) and the proper drain intervals.I always follow the first two recommendations (viscosity, type) and "half" the last (drain interval). For various reasons (many of which are not based on pure technical analysis) the drain intervals on new cars have extended way beyond what I consider prudent. Me, since I own, not lease, my cars, I always reduce their recommendations by cutting them at least in half.  That, however is my habit. Since I can do an oil change whenever I want - no appointment necessary - and the labor is free, it's really not that expensive.Buy the best oil filter you can find, warm the engine to get all of the dirty oil mixed together and the water evaporated and go change your oil! (But always wear rubber gloves, dispose of the oil properly and wash your hands very well (used oil is a bad thing.)