Curious behavior

I have had my first Prius for about 2 weeks, and am continuing to learn things, sometimes the hard way. I was driving my wife to a doctor's appointment today. Dear thing, she is so tolerant, I was showing off my "pulse and glide" skills that have been getting me upwards of 70 mpg under appropriate conditions. There is a brief section of the 25 mile drive that is on freeway (higher speed required), so I punched the cruise control button to hold speed at 55 mph. No response. Hmm. That's interesting. The first time that has happened. Repeated attempts to activate cruise control were to no avail.

We exited the freeway onto a 45 mph, 4 lane road (perfect for pulse and glide). I checked the cumulative trip mpg and was shocked to see 50 mpg and under. This was despite rather serious pulse and glide segments that usually give me 70-75 mpg. Odd, I thought. I dropped my wife off in town and made my way the few blocks over to my work, where I was going to stay for a while, and further things seemed wrong. First, the ICE wouldn't turn off when I stopped. Second, it seemed like releasing the accelerator pedal resulted in more deceleration than usual. What the heck is going on, I thought.

When I finished my work and headed out to the car, I thought about the persistent ICE and the exaggerated deceleration and I realized I must somehow have gotten the car in "B," but I couldn't figure out how. (It was definitely in "D" when I started out from home.) Could there be a software bug?

Then I realized what must have happened. In our enthusiasm for protecting the beautiful, new carpeting, we had purchased some cheap plastic mats for the front of the car. My wife had spent some time on our way today cutting a piece to go over the middle between the driver and passenger seats, and in the process had leaned over toward me to get the plastic material in position. She must have inadvertently bumped the shift knob downward, shifting the car into from "D" to "B."

I have looked in the manual to see what it said about the "B" mode, and I find very little except that it is designed as an engine break for prolonged, steep downhills. Here on the gulf coast we have no such hills (Alas!), so I had not tried out the "B" driving mode. Apparently cruise control cannot be activated in that mode. Keeping the ICE on (for braking) and greater deceleration make perfect sense for that situation, but it certainly can surprise you with low mileage if you don't notice your using it on the flat! (In desperation for a hill, we sometimes drive back and forth over the freeway overpasses just for excitement, but this gets old after a while!)

Cheers!

 

Yes, I was definitely in D when it must have happened. (We were driving along on our way.)

No mystery here, just interesting how easy it is to bump the shift lever without realizing it.

 

I suspected that others might have accidently bumped the car into "B," considering the design of the shift lever. Perhaps it would be a good idea to have the B mode position in a downward position but in an additional, vertical notch to the right of the rest position. Moving the lever to the right and down (and having it spring back to the middle position) would be less likely to achieve by accident, but no more difficult to negotiate than putting the car in "D" (to the left and down).

Admittedly a minor issue. Just a thought.