So I do not pretent to be the expert nor have I read every post in this forum. So these will only go down as observations. I bought my car recently (on the entry to winter here in Southern Texas). I watch the Cons. gauge like a hawk to see if I am going up or down. Currently our weather is stringing between 50's and the 80's in the same day. My car is still new and I just put my new springs on...so I am looking for a reason to drive it any time I can. I see that early in the morning (8am while it is in the 50's)...it is a bit challenging to get the const. value to rise after a considerable drive. And no heater, etc in use. However at mid day (around 1-2pm ) and the temps are pushing 80....I was able to drive the same general path and time frame, but much to my amazement....the MPG const. kept going up and up. Same tank of gas, same driving techniques. Just raw temperature seems to be making a huge impact. I am not saving any money with this damn car...I drive it more than needed just to see if I can improve my mileage. I am using the Cons. gauge to keep myself in check...I assume others are doing the same? I still have a lot to learn about this car.
Welcome to the wintertime blues. Imagine if you will temps down in the teens. This morning it is 1F outside. I average 43-46mpg in the winter (do have studded snowtires on as well). It is tough, but I got to remind myself that it is getting better than anything else out on the road. Relax and enjoy the ride.
I have had my Prius Five about 3 months so I have not had any hot weather in Kentucky to drive in yet. The best I have gotten is 48.3 (calculated). I hope I can get in the 50's next summer. I knew I was sacrificing MPG with the Five but it's hard to read about other's 50's and 60's MPG.
That's so true - it's easily to forget the car you came from has the same issue, but no way to tell you!
Today's high was -20°C/-2°F. I'm struggling to hold 48mpg indicated (which is probably 45 or lower calculated)
I've kept years of data that show the temperature and mpg correlation. It's posted on my website - Paul's Prius Home.
Make sure you're not returning to an already warmed up engine when doing the testing at 1-2 pm. It's much easier for it retain heat from the previous warm up cycle later in the day as opposed to letting it sit overnight.
After being parked this long, my Prius still retains 13 to 16 degrees from the morning warmup cycle, when parked in an underground garage. Any outside sun could add more.
So a valid comparison would be to park overnight in an underground garage (with consistent temperature over 24h period) and test first thing in the morning vs. 1-2 pm.