synthetic oil, effect gas econ?

Mine is strictly a non-scientific response, so don't ask me for empirical data. That said, I switched to Mobil 1 about a year ago (for no apparent reason) and have consistently observed a 1-2 mile per gallon increase in my fuel economy. I have always favored fuel economy over other performance parameters in choosing my vehicles and driving them since owning my very first car in 1970, so even though I do not keep detailed records the way someone like IRV does, I am highly conscious of day-to-day fuel economy.

I doubt that saving one or two miles per gallon on fuel recoups the additional cost of synthetic motor oil versus conventional motor oil, but it probably makes me feel better, anyway. I knowingly lost those same few miles per gallon when I installed ridiculously oversized tires on my Element three years ago, so at least perhaps I've regained the original fuel economy specs my Element was capable of in the first place. For me, the tires were worth the fuel economy trade-off I knew they'd produce.

Someone like MikeQBF or Dom.five could reasonably prove many other benefits of using synthetic motor oil, so I humbly defer to them on those points. Perhaps, because I like my Element so much (and fear Elements will cease to be produced in the near future) I seriously do intend to keep mine "forever", and doing all the best things for it seems to be a reasonable means of achieving that goal. That, and I'm old, so "forever" is certainly a relative term here.

Personally, my brain tells me that synthetic oil is overpriced overkill for an ordinary passenger car engine, but now I've confessed that even strictly logical old me actually uses it, why would anyone else resist using it? ;-)