Recently drove from lovell wyoming to sheridan over highway 14a. The total altitude gain is about 6000 ft in 30 miles with the last 10 miles up a 10% grade. The Prius finally ran out of battery power on the 10% grade but was still able to maintain 35 to 40 mph on the gasoline engine alone. It was 90 degrees in lovell when we left and had no heating problem. Was quite pleased with the performance. 2004 Prius with 27,000 miles.
What do you mean when you say the battery ran out? I thought the system never let the battery run out and it just taps power off of the engine to recharge. If it really did limit your speed why did you not just pull over for a few minutes and let the engine idle and recharge the battery?
pulling over doesn't get you where you're going any faster and doesn't do anything to help the system. The battery will essentially stop contributing power when it drains to the 1 pink bar (40% SOC) level...you're powered by ICE only at that point (for all intents and purposes for those techies who wanna split hairs). Pulling over may let you charge the battery, and then it'll let you go a bit faster when you start again for a while, but on a steep grade it'll drain fast and you'll have wasted time sitting.
I've run the battery totally down on I70 heading towards Eisenhower tunnel many times. It's really not a big deal. The car can still climb at 65/70 mph, although if you get behind a slow moving car it takes a while to get back to speed with no battery. The downhill fully charges the battery in about 10 minutes. (It's the only time I've seen full green bars). It takes a continuous climb of about 5 minutes at close to full throttle to fully discharge the battery. Any rolling hills will allow the system some recharge time.
I've had exactly the same experience....daily up and down Parley's canyon...a 20 mile ride up...one pink bar for the last two miles...but 65-70 and if slowed down....it takes time to recover.... back down the moutain to all green bars...
This forum has been enormously helpful to me, since I just moved to Denver from Chicago, where in the 5 years that I've had my Prius (2005) I never had an experience of the battery running close to empty. I was terrified that the car was going to die when driving up into the mountains recently--not knowing that this wasn't going to be an issue. Thanks everyone for your notes.
I agree with Evan. Whenever I go from Sacramento to Reno over the Sierra Nevada range (160ft. to 7,227ft.) in colder temps I will often see the battery run down to 1 pink bar (40%) and power drops but maintaining the speed limit is easy enough.
I had a strange experience while going West to East over the continental divide (I-70 from Dillon to the Eisenhauer Tunnel). For those unfamiliar with this pass, it's quite a bit steeper going West to East and offers no opportunities to recharge. I had it at 65 (IIIRC) on cruise control. Suddenly cruise control quit, the engine raced and the car slowed dramatically. I got into the slow lane right away and it was all I could do to keep it at 55. The battery must have consumed the last of its available energy. I wonder if the Echo's engine races like that to go up the same pass?
It's also possible to run the battery down to zero without going over the mountains. Stuck on the highway for about 30 minutes, just inching along for about 3 miles of a slight uphill. Finally, when I got past the accident, trying to get up to speed (55 mph), it was clear there was no help from the battery.
Good to know. Never really took the Gen 2 out to any steep grades (just climbing the local ski hills but even then, I've never seen the battery drain), only the Gen 3 has seen the Rockies but it didn't break a sweat. You guys must have steeper and longer grades than those around here.
I do that pass all the time, both directions. Definately is worse West-East, but I never have this problem. I do not use cruise control, I just floor it, which you dont need to be afraid of. I have a GenII, so I have less power than you. However, I can maintain speed at 75mph no problem. Battery drops to low and quits contributing, but the ICE is more than powerful enough. This is with me and sometimes 300-400 lbs of cargo. Are you afraid to put the accelerator "pedal to the metal", or does the GenIII really limit output power that severely?
Thanks for this info, I am going to do this soon. How is the Prius in the cold and snow? Any pit stop after Sacto that you can recommend?
What does this do to MPG? Whenever I was in SF with 3 adults in the car, I hate going up the hills, the engine has to work so hard.
While going up the hill the MPGs read in the single digits. There is no way around it. The only technique is to go slower and even then you reach a point where it is less efficient, and the best you can do is maybe in the high teens. Average for the high speed highways with mountain passes generally stays around 42mpg to 44mpg. Once I get back to the city, I can get 55mpg-60mpg driving around. But then when I go home, it is a jumbo incline that squashed mpg averages to low 50's and sometimes 48. No other car could do it better.
I also have a Gen II (2 fo them). I don't experience that problem when I start that climb with an all green battery but the last time I had only blue bars. I like to use cruise control because I've always believed, maybe incorrectly, that the cruise control's continuous input will get better mileage than my on-again-off-again personal attention. I wouldn't say I'm afraid to put the petal to the metal. I'm not sure how it would have handled if I had done that from the beginning. I do know that, once the battery is depleted (or just low), it takes forever to gain velocity on those steep mountain passes. Going East to West over that pass, a truck going about 55 pulled out ahead of me (in the left lane) to pass another truck that was going even slower. It took a loooong time to get the Prius back up to 75.
