About the only thing i can think of is to make sure your air filter is really clean as there is simply less air in higher altitudes. Some people have found that using one grade higher octane gasoline reduces the chance of detonation in internal combustion engines as the 02 sensors somes "lean out" too much in high altitude scenarios.

I have no direct knowledge of how this would impact the drivability of the prius but I do seem to remember some vehicles models in the past that have specific tuning parameters for Colorado which basically compensate for less air...

Wouldn't worry about it too much. just use common sense and maybe keep an extra blanket, flashlight, and some snacks/water in the car if you do have an issue and get stuck waiting for help to arrive.

My wife and I drove from Nanaimo, BC to Erie, Colorado to visit our Granddaughter last fall. Never has a car handled better than the Prius. Mountains offer no obstacle at all. Many cars with much larger engines than ours were passed on the steep climbs. Most of the time in cruise control. With the ECVT transmission there is no shifting, thus it is smooth traveling with a very large smile on our faces.
We have also traveled to North Carolina from here with the same smooth, quiet results. Our mileage always averaged over the 50 plus mark even when calculated.
Enjoy and let us know your feelings about your trip.
Bob

I live in the mountains and am currently getting on avg 57 to 64 mpg. I am very pleased. Plus my Prius has alot of power to get up steep climbs too.

The car will do fine in the Rockies. I've taken mine up into the mountains many times and haven't had any issues. Round trip I've ranged between 47 to 50 mpg on these trips.

I don't have a Prius... but today, me and my SUV were passed on a very long steep climb by a Prius with four adult occupants. :huh: I was left behind wondering why am I driving a heavy guzzling beast. So, I would assume you would be just fine.

Something else to keep in mind is if you don't use the cruise control, make sure you start giving the car a little more gas at the beginning of the grade you're driving up, and keep the engine's RPM up as you climb the grade. The car will do fine holding speed, but she don't like to accelerate up a grade, especially a steep one.

Maintaining speed is the key.

My experience with the Prius is that its great in the mountains in terms of handling so long as you dont have to deal with snow - which shouldnt be a problem this time of year. The only thing to watch is the battery charge level when you are climbing for an extended period of time (Related to the point made earlier about Prius not liking to accelerate up hill). My experience is that when the charge gets down to low levels (i.e., red bars) that performance is less impressive. The only time this happens is extended climb. Truthfully, not much you can do about that other than try and conserve battery on downhills.

<div class='quotetop'>QUOTE(maine12 @ May 15 2007, 03:21 PM) [snapback]442822[/snapback]</div>

In some high elevation areas, 85 octane is sold as 'regular' instead of 87. I have used this in 2001 Prius and the car seemed to drive normally.

Its highest climb (I think) was to 10000 feet, Bristlecone pine forest, CA. Other Prius have been over 14000 feet on Mt Evans,CO.

Remember to shift into "B" on long downgrades that would otherwise require you to ride the brakes. And then remember to shift back to "D" when you leave the mountains ("B" will reduce fuel economy in normal driving).

Don't be afraid to floor the gas pedal as needed. The engine will roar, but that is completely normal when high power is required. The computers will not allow the engine to redline.

<div class='quotetop'>QUOTE(maine12 @ May 15 2007, 04:21 PM) [snapback]442822[/snapback]</div>

FYI,

This item seems inappropriate in this section (Prius and Hybrid News), it should have been listed in "Prius Main Forum".

Regards,

Drives great in the Sierra Nevada and Coast Ranges, summer and winter. Love the VSC control. Handles very well.

<div class='quotetop'>QUOTE(maine12 @ May 15 2007, 08:21 PM) [snapback]442822[/snapback]</div>

Have had a few trips through the mountains of Colorado and didn't have any problem. I remember one extended climb led to losing some speed as I was nearing the top, but only got down to around 60mph I think.

We use B a lot on the downward portions and for the uphill climbs just kept it on cruise control. The engine gets louder, but never overheated or anything. The averages for the trips were around 48-50 mpg.

<div class='quotetop'>QUOTE(richard schumacher @ May 16 2007, 07:39 AM) [snapback]443304[/snapback]</div>

Why wouldn't you ride the brakes? You would get the re-generative braking function to charge the battery much quicker by using the brakes. If you are concerned about the brakes over-heating and fading, I would switch to ceramic pads and put in some high temp brake fluid. Brakes cost much less to repair/replace than the drivetrain (which takes the stress of coasting when you select the B setting). Also, if you switch to ceramic pads, you will get a shorter stopping distance....

Regarding Octane. When driving at higher altitude, the air is less dense which means that it becomes more difficult to ignite the fuel. Thus, your vehicle will run better with a LOWER octane fuel, not higher octane. That is why high altitude communities generally sell fuel which is 2 octane points lower at each fuel grade level.

Re: regenerative braking. The prius uses regenerative braking whether you put the gear shift lever in "B" or you use the brake pedal. The only benefit to the "B" setting is that it consistantly uses some regenerative braking, so you dont need to manually modulate the brake pedal.