I used one of the old fashioned pen looking tire gauges. I learned about the better mpg trick from eco modders. works great. I drive 70-120 miles a day so every few gallons count. I run normal psi in winter and rainy seasons and properly rotate my tires. Wear on tread is always pretty even.

 

Whatever floats your boat, im glad i found the reason why i was riding so rough, doubt i'll loose much mpg. So many other factors contribute, like traffic i sit in and how i drive.