Synthetic oil. Does it increase gas mileage?

I have recently surfed the Internet trying to find out if using synthetic oil will increase gas mileage. After reading more material than I thought would be available about this subject, it is difficult to find any absolutes, since everyone has a difference of opinion.

The reason synthetic oil will probably help you achieve greater gas mileage is due to the fact it tends to lubricate your car’s engine better than conventional motor oil.  Because of the better lubrication, there tends to be less friction within the engine, which causes the engine to run more efficiently, helping you achieve greater gas mileage.  Source.

This makes sense. A slippery engine would in theory reduce friction and increase mileage.

Possibly, but only slightly. You will see less than 1 mpg difference and you may not see any negligible difference. Depends on how you drive and condition of the vehicle. Lots of factors come into play with your actual mileage.  Source.

Slightly? Depending on how you drive also makes sense.

I even read some say that tire pressure, tuneup and other engine maintenance makes more sense than slippery oil does.

So my question is. Does anyone here use synthetic oil? What’s your opinion?

Comments welcome.