Hey everyone, I am encountering a strange problem in my 2007 Prius. 179K miles, fresh oil change, fresh trans fluid, well maintained and always driven with care. Here is my issue: I just drove back from NYC to Oregon. When I was in the mountains near Mt. Shasta, California (3000ft elevation) it seemed like I was losing the ability to coast downhill. I was coasting down a 6% grade going 65mph and would slowly lose speed. Even on the steep grade I would lose 1mph every couple seconds which seemed very odd. I could start a half mile steep grade at 70 and end at around 50... Then when it would flatten out and I would start a VERY mild acceleration, from 55mph to 60mph, my instant mileage on the display was dropping to 17mpg. After about 30 min of driving the problem went away, but this has happened to me very intermittently and is somewhat worrisome. Also, I was not in "B" mode and even when I tried switching to neutral I would still lose speed. Just felt as if the brakes or trans were holding the car back from a "freefall" down the steep grade. On a steep grade in Arizona I was increasing speed by 1mph every couple seconds so I know how it should feel. Sorry for the lengthy post, I just don't know what in the heck is going on! Thanks! B
Problems have been documented about brakes dragging and it's not limited to the Prius. I would definitely get them checked immediately. If that's the problem the friction heat can cause a wheel to catch fire.
I had the same thought as srellim. If your emergency brake isn't working right and you accidentally left it on, then that could account for inexplicable decelerating.
Ah ok. It really does seem like it could be the brakes. I will have it checked as soon as I can. Thank you both!
