Hi Bob,

Good information. I wonder if you'd see such pronounced differences at lower speeds after warm-up? Harder to do, as finding a route you could run under the same conditions to simulate non-highway driving.

Living in a part of the U.S. that gets d*** cold (esp. this last winter where we went days wo/ seeing 0 F), the biggest hit is the time it takes to warm up. We only have a 5 minute commute, and our mileage goes into the crapper (I'm talking tanks in the mid-30 mpg when this is 75% of our travel) in the winter because we never get warm enough for the ICE to kick off or allow the electric engine to do more of the work.

Any FAQ on temperature affects has to discuss the problem of warm-ups and the much more detrimental affect of cold temperatures on short trips. There are a number of posts discussing this at length that could easily be adapted to serve the function.

'06 Prius w/ option pkg. #4 in Driftwood Pearl
Northeast Iowa