Extended driving on an incline

as i posted last summer .we had taken a cross country trip of over 6000miles, and had climbed through the sierras and rockies as well as into some climbing in and near sedona az...as we were climbing out of carson city and into tahoe country...we never lost our 2 last pink bars on the SOC...it seemed the prius protected the battery as we climbed...we had plenty of torque and power...we were passing trucks and smaller cars and i had plenty of pedal left...never did floor it...speed were 65-85 depending ...addtionally, the same thing occurred in the rockies as well...never lost the last 2 bars of charge...granted the engine kept spinning at a good rate...but it was working in tandum and and the MFD showed both batt and ICE working together the whole way up...

 

Prius has 110HP if you have enough juice in battery.
It is 76HP vehicle if you used up the battery.

Ken@Japan

 

In reading boards and magazines for over a year, I have only heard of one instance where this "drained battery slowdown" actually occured, and that was (if I remember correctly) in the Motor Trend magazine test over Cajon Pass, where they admitted to running flat out (speeding) all the way up the hill and found the battery depleted and they had to slow to 50-60mph. I have not heard of anyone driving legally and encountering this condition. I tried up Gaviota Pass and could not deplete the battery, despite driving 75+ up the grade (not higher for fear of CHP, not because it wouldn't). I was surprised, but I couldn't do it!

 

I've heard that a sustained incline will evetually deplete the battery and leave you with ICE only. In my experience driving here in Utah's Rocky Mountains I can tell you that such an incline dosen't exsist here in this State. Nor does it in Wyoming unless it's Teton Pass which is one of the few highways there I haven't been on in my 05. In my experience this car is a mountain goat and has yet to meet a hill it dosent like. I live on the west bench of the Wasatch Front and drive up and down steep hills alot. The battery charge/discharge evens out. Ive been on I-70 going west out of Denver in other cars and know if there is anywhere that will drain your battery it's there but havent had my Prius there yet. Also the road up to Sequioa Natl. Park is very hairy and would be hard on the battery charge. Outside of the three inclines I've mentioned above I don't know of a road (maybe Rocky Mountain Natl. Park also?) that the Prius won't gobble up. Thats a very small percentage of the roads in the western US and chances are you wont be alone crawling up those.

 

Standard yellow advisory signs warn of percent grade in western states. It is not unusual to see signs warning of a 5% to 12% grade ahead.

I regularly drive long steep inclines (I-5 over the Transition Range between California's Great Central Valley and Los Angeles Basin) as well as I-80 (Donner Pass, Sierra Nevada; Hwy 168, western slope Central Sierra Nevada). Our Prius performs wonderfully. Yes, the battery drops with increase in elevation, but the battery maxes out to full green plus going down hill. Fuel economy range averages about 45 to 50 mpg on long trips involving steep inclines. The B-mode works well in retarding the vehicle on long steep inclines - minimizing the use of brakes, except on the steepest grades.

 

On a trip to Yosemite I took our Prius with three adults and provisions up and down the Old Priest Grade shortcut on Highway 120. Many people refuse to drive it because Old Priest Grade is a 1500 foot elevation change in 2 miles - for an average grade of 14+%. There are a couple of steep sections bordering on 20%. The Prius made it with no problems and with plenty of power to spare. It's really fun taking passengers who have never been on Old Priest Grade. It scares the hell out of lots of people.

On the way down Old Priest Grade, you had better be in “B†. . . even then you will have very shiny and hot front brake rotors at the bottom.

As of January 1, 2004 vehicles exceeding 7,500 pounds are prohibit on Old Priest Grade.
http://www.dmv.ca.gov/pubs/vctop/d15/vc35715_1.htm

Back in the old days, stage passengers often had to get out and walk as the grade was so steep the horses couldn’t pull a loaded stage up the road.
http://malakoff.com/goldcountry/bigoakfl.htm

Mystery Jugs.
http://www.yosemitegold.com/mysteryjugs/jugs2.html

http://virtualguidebooks.com/CentralCalif/...stGrade_FS.html
http://en.wikipedia.org/wiki/Moccasin,_California

 

In the west is quite common to see the % grade on a down hill to warn the truckers. Also have you seen runaway truck pull outs? A pull off the road with an uphill the surface with increasingly deeper gravel to slow the truck down. Not uncommon in the Rockies, Cascades and Sierra Nevada's! Come on out we will instruct you in mountain driving. Scenery, spectacular!

 

I've driven the I-70 Eisenhower route both ways on a camping trip, no issues doing 70 MPH. I've driven the pass outside of Jackson Hole (is that Teton Pass?), no issues doing 50-60 MPH (depending on curves and traffic!). Granted the engine is running faster and louder and the battery depletes to 2 pink bars, but you get it all back on the other side.

Completely blows away ANY notion that a larger engine is needed...just better technology in the HSD system. HSD is just the right for size and output for what it was designed to do: move people comfortably and safely and efficiently. Not too much for those slow, flat trips, quite enough when asked to get you over a mountain.

 

That is not entirely true. When I got my Prius I purchased it out of State in Montana and drove home to Washington. On the 4th of July Pass I got stuck behind a series of trucks climbing at about 40-45 mph and when I could I easily accelerated to 65 mph and passed them on the up hill. I had 2-3 bars at the top of the pass and preceded to go all green on the down hill with stealth at 65 mph. No problem, and that was a fair grade with warnings on the down hill. Next time I drive the other way I will try to remember to look at the grade signs. Another pass with runaway truck pull outs and signs at the top for trucks to stop and check their brakes. The worse uphill down hill I know is on I84 just east outside of Pendelton Oregon. That is a hill.

 

Last summer we went on a 3-week road trip in our Prius. We traveled from the San Francisco Bay area through the Sierra, across Utah and Devils Gulch and Colorado. We went up to 12000' above sea level in Rocky Mountain National Park. We had no problem making it up the mountains - we actually did it twice. We saw pink bars on the battery level but more that made it up on the way back down. We hit a lot of other places on our way back through Arizona and Utah again and Nevada, Death Valley, Yosemite and home. Great trip and couldn't have asked for a better car to do it in.

 

What SOC did you have during the passs ?
Remember, we are talking about depleted battery, ICE only, steep incline conditions.

A safe passing depends a lot on the road, but you probably do not want to be in the opposing lane *too* long

 

This thread is pretty timely, as I just returned Thursday from a trip to the bay area.

I now have just over 20k miles on the odo, and at almost 1500 miles this is the longest trip I've taken in the Prius. I drove through grapevine both ways and took Hwy 17 down to Santa Cruz twice. I also did some hilly driving in San Francisco and some extended 85-90 mph cruising through the central valley. Mosty though, I was putting around between Palo Alto and Redwood City.

I have to say that the Prius really shined on this trip. It handled all the mountain passes just fine. For the long grinds going up Grapevine I could leave the cruise on 65 or 70 and the Prius had no problems maintaining speed, and a few times when people cut me off and I had to slow down, it regained speed easily. I haven't made this drive in over 10 years, but the Prius handed it much more easily than my old 4-banger Toyota truck ever did. For whatever reason, I did not feel the need to use B mode at all on this trip.

The thing pretty much kicks nice person for long trips. I only wish the seats were more comfortable.

 

The maximum outputs occur at different RPM's

 

Went LA to Vegas in February, and had no problem with Baker grade. It climbed as well as our Outback did last time, and got over 48 mpg, which the Outback never came close to. The only slowdowns were due to slowmoving trucks and Suvs, and no problem doing 70+ up the hill. Two people, full trunk.

 

Really long continuous grades are actually pretty rare. Usually you have a few miles of up, then some relatively flat, or down, then more up. Driving from LA to Mammoth (sea level to 8,000 ft.) I had no problem with power anywhere along the way. The Sherwin Grade, just outside Bishop climbs from 4000 to 7000 in four or five miles of continuous steep grade. I had no lack of power anywhere on the grade. This week I have to go to Las Vegas. I'll let you know if there is any problem with the notorious Baker grade.

 

"They can't climb hills" is another Prius myth. Climbing the Canadian Rockies, even loaded with 4 people and a month's worth of camping gear, was no problem.

 

My biggest problem was trying to get the battery to drain, so I could charge it up on the way back down. It kept charging the battery as I was going up with 5 people in the car, leaving other cars in the dust.

And I totally agree with Stairman, it's surprising to me how much downhill is involved in going up a mountain.

 

I got to take the Prius on its first roadtrip last weekend, up the I-5 thru the Grapevine to San Jose and then back thru the Santa Cruz mountains on CA17, then south along the coast (CA1 and 101). The Prius handled like a dream on all the uphills and downhills. I did put it into "B" on some of the twisty downhills on the 17 to keep from getting up too much speed, and it did spectacularly. Coming home, we went thru the Sepulveda Pass and again it handled like a pro at 70+ mph in the righthand lane.

This weekend we're taking it to Mammoth for another roadtrip, this one involving snowboarding. There's a long steep incline just north of Bishop along the 395. I can't remember the grade %, but it's pretty steep. Steep and straight enough that when you're coming back down it on the southbound side, one does not need to use the accellerator to maintain speed at ~65-70mph and "B" and braking aren't necessary unless a vehicle going slower than the speed limit is in the left/passing lane. And this incline goes on for a good 10-mile stretch.

Can't wait to test it out some more!