Mountain Passes

I took a trip over the mountains in Colorado and got 55.5 mpg (the best so far). Long uphills mean long downhills

 

Climbing up the west and east sides of the Sierra Nevada last Halloween was no problem. Your battery will essentially be drained and the milage up will be terrible but like stated above, the downhill slope will fix that.

 

I've driven up and down several long, steep passes between the Pacific coast and the Rockies, with no trouble. Most trips were fully laden with camping gear and people, and the overall mileage was surprisingly good. As long as you don't expect to break the sound barrier on the way up, Albertus, your car should be fine.

 

I always like to see what a vehicle new to me will do going up the Bozeman Pass- not real long or steep but enough to communicate what cajones are involved. Prius went up it at 95, never seemed to labor.

 

<div class='quotetop'>QUOTE(hyo silver @ Oct 21 2007, 04:52 PM) [snapback]528536[/snapback]</div>

We also crossed the Rockies this summer-- two adults, two teens, roof rack, all the camping gear. Ditto on hyo silver's response. We chose to not use cruise control on the longer steeper climbs because it tended to send the engine screaming. If you are interested in the details of our trip you can go to--

http://www.priusonline.com/viewtopic.php?t=11065

PA P

 

That's a nice account, PA, I don't think I'd read that before. We kept all of our stuff inside, with no roof rack, though 'stuff' was the operative word. I didn't use cruise control much at all, but I came to regard air conditioning as a safety feature on long, hot days behind the wheel. I kept to the speed limit as much as I could, at least up the big hills, but down the mountains and on the Prairies was a different story.

I think the Prius is a great family car, and makes a quiet and comfortable cross-country cruiser.

 

I've driven up multiple mountain passes with no worries. Left it in cruise control. People think the car is always using the battery, it doesn't always use it for propulsion. Often times the engine will charge the battery even while going up a hill!

Don't think you're going to go 95mph up a mountain pass. That's just stupid. Set your cruise control to 68-70mph and enjoy the view

I drove 257 miles up and down three mountain passes last weekend and got 51.9mpg.

-Dave

 

I heard a few years ago (I don't remember where, and I don't have any reference to back it up, sorry :mellow: ) that the first-generation Prius would gradually lose power on mountain passes. Long uphills would drain the traction battery, then ICE would spend more of it's energy charging the battery and less on the wheels. And that this problem was fixed in the current generation Prius.

Does this ring a bell with any of our resident experts (Galaxee, Hobbit etc...)

 

I did I-80 from San Francisco to Salt Lake City in August. No problems. I wanted to average 75mph, so I was letting the engine rev pretty high, but I never experienced any loss of power problems. I did see the battery bottom out a few times, though.

The interesting thing is that my overall mileage (reset when I left SF) actually increased between Sacramento and Reno. The next day saw me going from SLC to Calgary, which is a really long trip, so to cut down on drive time I was holding 85 for large sections of Idaho and Montana, resulting in a lot of high revving (many were the times I saw the engine shift into high-load mode and rev around the limiter at 5000). As far as I can tell the car still runs fine.

 

Go ahead and floor it on the way up. The engine *will* roar, but this is completely normal: it's just providing the power required, and the computers will not let it harm itself.

At the other extreme, the nature of the Prius drive system makes it impossible to stall the engine. You can crawl up a 10% grade at 1 MPH if you want.

 

Somewhere north of 3000 RPM is around where assist starts being
drawn from the battery. If you're patient and think like a loaded
semi instead, you won't pull the battery down as much but then of
course that leaves you less headroom for regen on the backside.
I've recently been doing a little playing in some hills too --
nothing like 9000 feet, but managing to keep reasonably high MPG
over some significant, battery-bashin' ups and downs regardless.
.
Oh, and the assist threshold *does* drift up and down depending on
vehicle speed. Nothing is really hard-threshold in the Prius except
those various transition speeds we all know about; that's one of its
best aspects.
.
_H*