2016 Floor Model

In March my wife and I purchased our first Prius, a 2016 Four Touring. It was one of two 2016 models left on the lot, and we got an amazing deal on it. Came with only 152 miles on it. From Day 1 we have loved it; loved it so much that I did the math and some searching and found another 2016 Four Touring sitting on a car lot not too ridiculously far away. Plus, we were getting the second one at an even better deal than the first!

Long story short, we now have two Prii(?). We love them dearly. However, we are noticing some relatively "significant" differences in mileage between the two. Prius #1 easily clocks 54 mpg on a regular basis and maintains a fairly predictable MPG flow over our commutes and errands. On a day warmer than 55 degrees, we will usually clock 56+ MPG.

Prius #2 was a floor model with only 35 miles on it when I picked it up at the dealership. It was in tip top shape. The salesman let me know that he had the mechanics "charge" the battery to make sure it was ready to go, etc., since it had basically arrived at the dealership a year ago and just sat in the building up until recently. After finishing the paperwork I hopped in and started the drive home. About 200 feet from the dealership the engine kicked into what I could tell was a "get the battery charged" mode. Not totally unexpected. Over the 7 hour ride home, 98% on the interstate at about 75mph, I was happy with the 50mpg that my new little buddy gave me. About what I expected, really. Now, having had the new one for 5 days we have noticed that its MPG readings seem to go all over the place, 54+ one moment to 48 the next. Just this morning my wife averaged 58mpg driving to her workout, then 48 on the way back. Yes, it averaged out to 54mpg, but we both seem to feel like this new Prius is all over the place in terms of MPG at times.

I told her we would keep an eye on it as we settle back into our normal routines after the holiday weekend. If this trend of wildly fluctuating MPGs continues, does anybody have a suggestion as to what it could be? My guess is that the battery maybe isn't holding its charge very well? Maybe the car just needs some seasoning? Did sitting for that long make the battery "stale?" It just seems odd the P1 has no issue sitting over the 50mpg level on a daily basis, and P2 seems to struggle to get there. Any thoughts/suggestions would be great!

 

Thank you to all who replied.

As @alanclarkeau suggested, I will try to fill it up and hope that kind of gets the computer back on track. That sounds kind of along the lines of what I was thinking.

I also snagged an app to help me start tracking the fuel for both Prii, much like @bisco suggested, as well.

Again, thank you for the suggestions. I'll update as my results start to build. Needless to say, it did not take long to fall in love with these cars. It's a wonder that hybrids aren't even more prolific than they already are!