Since the temps have gone down a bit from the 105°F its been here for the past 4 months, the MPG increased a bit in the Prius.
Its probably a bit optimistic but this is what MPG the computer in my car showed before I filled up this morning. I still had over an 1/8 of a tank left, but I don't like to get too close to empty.

 

When its colder the air is more dense, you get more air per square inch, that means more power and the engine doesn't have to compensate with fuel

 

also, less A/C is used....

 

Also, I think batteries run more efficient when cooler. So you're getting tons of benefits!

 

64.5 MPG? Must be nice

 

double positive with the increase in air density and the lack of AC. Now all you have to do is make sure that you tire pressure doesnt drop and decrease efficiency

 

Damn, so jealous, 64.5 MPG? I get 20... you get ~3x better mileage than me. That's 3x more money in your pocket...... Oh well.

 

Hopefully it helps my mileage. 11 mpg is just not cutting it. If this doesn't change soon, this car is going away.

 

That is not true for modern EFI cars. The computer knows that the colder air is denser and adds more fuel to compensate. If it didn't do so, the car would be running extremely rich at warmer temperatures and dangerously lean in the cold.

 

It's actually the opposite. Batteries are more efficient when it's warmer.

http://chemistry.about.com/od/howthi...oldbattery.htm

 

Yep.....the oxygen-sensor in the exhaust manifold constantly checks the exhaust gas for the proper air-fuel ratio and sends a signal to the engine-computer computer to compensate the injector-flow as needed.

Running too-lean in the cold, BTW, is probably not as harmful as running too-lean in hot weather. Lean mixtures generally add engine heat by raising the combustion temperature (which also increases the possiblity of spark knock/ping). Cold weather, of course, is more forgiving of too-hot engine conditions than warm weather. Too-lean conditions in hot air-temperatures can do much more harm than in the winter.

 

yes warmer temps help the batteries, but not 105°F

 

these are perfect times for good mpg.... soon winter will come, and they will go down drastically. Luckily you do have G3 Prius, its exhaust recirculation system is very good. I wonder how much Sonata Hybrid guys will complain in winter... or leaf/volt guys.