Driving in the mountains - Any problems

<div class='quotetop'>QUOTE(Ronald56 @ Jul 18 2007, 11:27 PM) [snapback]481401[/snapback]</div>

No worries, buddy, I just did a similar trip! Going up steep Utah mountains, outside temp in the 100s, me and a passenger and luggage, A/C on to a more than comfortable level (kinda cold actually) and cruise control had no issues. No overheating issues either and I got exactly 50 mpg average on this 700 mile trip! I was driving a base 07 model.

 

No worries. The engine will roar, but that is completely normal as it generates the required power. The computers will not let the engine over-rev.

 

I had an driving experience last week with mountain driving. I had four adults in car at ~8000 ft. climbing a steep grade, down to one purple bar (or less) with A/C on, with temperature in 80's. Needless to say, the car didn't have a lot of power, and I didn't try the cruise control. The A/C seemed to do OK, car didn't overheat, but it was noticeably hot when we reached the top and stopped. I wouldn't like to drive under these conditions for long periods of time, fortunately it was an unusual situation. The average trip mph dropped to less than 40 going up, but recovered to about 50 coming back.

 

There is some pretty extensive discussion of mountain driving in the Prius in this thread. It won't climb like a V8, or even a V6, and your mileage will suffer. No surprises there. I've never yet found a mountain mine couldn't climb, though I have found some where I had to climb pretty slow.

 

<div class='quotetop'>QUOTE(Mad Hatter @ Jul 19 2007, 11:07 AM) [snapback]481609[/snapback]</div>

Mileage suffers going up, but it recovers going down! You can't just go up without eventually coming down, right.. My average was 50.2 going up and then down the mountain - close to 700 miles total in two days.

 

One other thing: if you find yourself riding the brakes while going down a long hill, shift to "B" to prevent the brakes from overheating. Remember to shift back to "D" when the danger of riding the brakes has passed.

 

<div class='quotetop'>QUOTE(richard schumacher @ Jul 19 2007, 04:09 PM) [snapback]481883[/snapback]</div>

I was under the impression that the physical brakes aren't used much on the prius. Especially when going down a long hill. I thought the brake pedal would either cause the generators to make more electricity, or use the engine to slow the car. With the physical brakes only being used under 7 mph, or in emergency stopping situations.

Is this not the case?

 

You're right, but engine braking will be used only if you shift to "B".

Once the traction battery is fully charged there's no other place for the energy to go, and the computers shift the braking effort to the mechanical brakes. On a long downgrade there is a danger of the mechanical brakes overheating. Shifting to "B" enables engine braking, which reduces the load on the mechanical brakes.

As to how steep a hill one can climb with the CC set to 70 MPH: try it and see. It cannot hurt anything except fuel economy.

 

<div class='quotetop'>QUOTE(Ronald56 @ Jul 19 2007, 09:39 PM) [snapback]482035[/snapback]</div>

Yes, it will maintain speed... the only cost will the the ICE being really loud, and your MPG will drop to like 9 sometimes, depending on the incline...

 

I've driven from Salt Lake City to Park City (up a canyon) several times - this is a pretty steep mountain road, on a typical summer day you'll see two or three older cars off the side of the road overheating.

Last time I had the cruise set at 66 and went up the whole way at that speed, no problem. Bad mileage, but the trip back down more than made up for it.

 

We returned from a 7,500 mile trip a week ago today. It included crossing the continental divide a few times as well as other mountain climbing. We chose not to just let the engine roar, so we got down to 35 mph at times. However we were fully loaded-- two adults, two teens, two tents, all camping gear, roof rack, etc. I've detailed more of our trip at
http://www.priusonline.com/viewtopic.php?t=11065
if you are interested. Not maintaining maximum speed on the steeper mountains was fine with us. Be patient and enjoy the beautiful scenery!

PA P

 

<div class='quotetop'>QUOTE(Ronald56 @ Jul 19 2007, 12:27 AM) [snapback]481401[/snapback]</div>

Ah, the diesel Rabbit! We loved that car in Indiana and then moved to the Hudson Highlands in New York. Barely getting 50mph going up the mountains with the accelerator pushed to the floor was a bit unnerving, we traded it in, a few months after moving here. It was downright dangerous on the inclines.
The Prius has no problems with the mountains here. I usually don't use cruise control in the mountains. Although it works fine, I find it a bit too aggressive for me. We had five adults in the Prius a few weeks ago, and it was great taking the mountains and that was in 95 degree heat. My mileage dropped to 46mpg for that week, but I'm back up in the 50mpg range with just me and the DH again. You will find the car handles differently with more weight, but no more than other cars do.
Have no fear, the Prius is no diesel Rabbit.

 

The last time I went to the Sierra's I intentionally tried to push the car on the Sherwin Grade just north of Bishop CA. This is a 6% grade which takes you from about 4400 feet in elevation to over 7000 ft. I set the cruise on 72mph at the bottom of the hill. This gives me an actual speed of 70mph according to my GPS. About 6 miles into the 8 mile grade the speed dropped to 68mph on the speedo. When I checked the battery screen the battery indicator was down to 0 bars. Once I leveled off at Tom's Place the battery began to charge up. I was alone in the car, but had ~250 pounds of stuff.

There are very few places in the country where you would find a hill this size. There are even fewer where you could drive up such a hill at 70 mph; usually such a steep grade would be on a winding road.

Unless you are a maniac, power is not an issue.

 

Most of our mountain passes include twisties so too high a speed isn't possible, but several passes allows fairly high speeds and the CC maintains 68-70 with roaring from the ICE to keep up the speed. Don't read your MFD for fuel economy as it is depressing. Generally, the Prius is passing other vehicles on the upgrades and the CC always is able to keep the set speed.

 

<div class='quotetop'>QUOTE(Ronald56 @ Jul 19 2007, 11:39 PM) [snapback]482035[/snapback]</div>

Yes it will.

 

<div class='quotetop'>QUOTE(Ronald56 @ Jul 19 2007, 11:39 PM) [snapback]482035[/snapback]</div>

Yes it will.