31's to 225's MPH decrease but MPG increase ??

When I bought the tacoma it had 31's on it. I just recently put 225's on and I have noticed a decrease in my MPH. I have a 5+/- MPH decrease. I used GPS MPH apps and google map to verify and I was correct. But, I did notice a increase in my MPG. 31's I got 250+/- and the 225's 300+/-. The only thing I can think is that it has been re-geared at some point.

I went with 225's, because that is what the factory sticker says.

Any other suggestion or am I crazy (LOL)?

 

225's are only 29" maybe ?

so you dropped 2" in tire height....

your speedometer will be that much off

Truck is geared for 225's & speedometer is calibrated for them

 

Also less weight. My tacoma had 31's and I went back to 235s. The 31s that were on it had kevlar in them also.