Can't get up the moutain

There is a city called "Dunedin", 400km south of me, that has a street called Baldwin Street. This is recorded in the Guinness Book of Records as the steepest street in the world (see: Steepest Street)

The steepest part has a gradient of 1m in 2.86m, so it is actually quite frightening to drive up - the houses on either side give you the impression that you are about to flip over backwards.

Next time I am in this city, I will try different things (standing starts, normal driving etc) to see what happens with my Prius.

 

Yeah, that's about a 35 percent gradient, 19.3 degrees. That's steeper than what I predict the Prius can climb with MG2 alone. I know it also has the ICE to provide torque, so it *should* be able to climb, just barely.

 

By design, front-drive vehicles cannot climb as steep slopes as rear drive one can (shift of weight to the rear tires). Given the skinny tires and low torque of Prii, they won't be very impressive in climbing hills, but they would be sufficient on vast majority of mountain roads.

 

Hmmm, it has become a bit of a challenge now. There are steeper areas where you could take a car, but not a properly formed public road, so I look forward to seeing how my little baby will go.

I will try pure EV mode as well, just to see what happens. It is only a short street about 30 or so metres (who would want it to be longer - lol) but it should be enough to gauge how the Prius handles it.

Watch this space in a couple of weeks ...

 

I suspect the issue with the steep mountain climb in Asheville is the dirty road. As everyone knows, Prius won't "spin" the wheels due to the Traction Control. It will simply not move.

I wouldn't be suprised if that was the case - I was unable to get up my icy driveway twice this winter.

 

<div class='quotetop'>QUOTE(rickdm\";p=\"73967)</div>

Rick:

I think this may be true, but not for the reason you stated - lack of torque.

The Prius has a *very* aggressive standard Traction Control system, not to be confused with the optional VSC. The Trac appears to be there to protect the hybrid system, as it can generate enormous torque.

In conditions like gravel, a little wheelspin is actually beneficial. As long as the tires can dig in a bit and you don't totally floor it, you should be able to keep going. There is no way to even temporarily disable the Trac, sorry.

I had a similar situation happen here in Winnipeg last winter, before my snow tires arrived. I still had on the Michelin Harmony "all-season" tires after the 2nd or 3rd blizzard of November.

I went to a local mall and wanted to park on the upper deck area, which is more convenient to one of the stores I wanted to visit. The parking ramp is fully exposed to the elements and had a nice sheen of ice from where cars were spinning going up it.

An older s*** box of a car didn't appear to have any trouble going up the ramp, so I proceeded as well. You have to make a 90 degree turn before entering the ramp, so a run-up was impossible.

I got about 2 car lengths up the ramp and the car just stopped. I kept pushing on the pedal until it was buried in the mat. The VSC was flashing (It does that when Trac is engaged) and the car was stationary.

Nobody was behind, so I was able to carefully back down the ramp. I ended up parking what seemed like 4 miles from the mall entrance. After that little adventure, I drove to an empty truck stop lot to try out the Trac, and I can confirm it also engages in Reverse too. If you get stuck, you will *not* be able to rock.

When my Dunlop Graspic DS-2 tires finally arrived, I immediately drove to that evil parking ramp to try them out. No problem at all, the car easily went up the ramp. I had to really floor it to engage the Trac.

I would say in the vast majority of operating situations, the Trac is good. However, by not having a temporary disable button (Even to just make the Trac less aggressive) there are some situations where you will just completely stop.

 

<div class='quotetop'>QUOTE(pepa\";p=\"74040)</div>

Pepa:

Say, you posted sometime last fall worrying about that very steep driveway of yours, right?

There has to be a way for Toyota to temporarily reduce the sensitivity of the Trac.

 

<div class='quotetop'>QUOTE(ceric\";p=\"74003)</div>

A poster on another topic (and possibly on another forum) wrote that, in snow, he went backwards up his driveway because the traction was superior.

"Low torque of Prii" is incorrect. The torque is actually in the Ferrari zone:

2005 Ferrari F430: 343 lb-ft
2005 Prius, adding electric and ICE: 377 lb-ft

Of course, some of the ICE's power is used to charge the battery, making this measurement misleading.

Like Jayman and pepa, I think the problem lies with the traction control. There IS a way to disable it by going into diagnostic mode - the procedure is probably in the archive here - but apparently it's highly un-recommended.

 

Isn't the rims 15" diameter alone, the OR of the whole tire being even greater?

As for TC, you could try putting it in diagnostic mode and take it slow. I don't know if MG2 is used in diagnostic mode though.

 

One of the tricks to this road is that it is fairly rough and it has three switchbacks of at least 120 degrees. You really cannot get up much momentum. Once you get to the house the views are spectacular, but that drive is really something. These are also folks whose world view would be very sympathetic to the Prius, but it could have been an older model that failed to make it. I will find out this summer.

rickdm

 

<div class='quotetop'>QUOTE(Stocky\";p=\"74004)</div>

Hey Stocky,

Baldwin sounds like a fun street to drive up and down, but I have no doubt the Prius can do it just fine.

At the bottom of your link’s page it states:
“Baldwin is recorded in the Guinness Book of Records as the Steepest street in the world, (but there is some dispute over this as only 6m out of the total street length of 30m is at the steepest gradient). Baldwin Street has a maximum gradient of 1m in 2.86m . . .â€

20 feet is not a problem for the Prius at that angle. I have a friend who lives on the hill in Sausalito (just across the Golden Gate Bridge from San Francisco). Her driveway is longer than 20 feet and about the same grade as Baldwin. The Prius bumpers scrape at the bottom of her driveway. [what people won’t put up with for a great view on very expensive land!! :roll: ]

In San Francisco, the two steepest streets are downhill only! Darn!! I drove the steepest uphill road. The Prius did fine, even with three adults and heavy baggage.

Have fun on Baldwin . . . and take pictures for us.

 

I enjoyed reading about the concerns my fellow Prius owners have about climbing hills. Seems to me, another concern should be about the Prius' ability to back up on the various street grades we encounter here and there. For example, San Francisco. Now there's a place where curbside parking mandates, by law, the front wheels be turned into the curb when parked. Now the electric motor is the only power for the drive wheels when in reverse. Some hills in S.F. are pretty steep; awfully steep. What would happen if the Prius couldn't muster the necessary torque for the job. Guess we'd just have to jump the curb and then get a wheel alignment. :roll:

 

<div class='quotetop'>QUOTE(whatshisname\";p=\"74164)</div>

Since, at low rpm, electric motors have such vastly superior torque characteristics than gasoline engines (Prius electric motor: 295 lb-ft of torque at 0 rpm, i.e., at start-up), this isn't likely to be a problem.

However, I'd love to hear actual testimony.

 

<div class='quotetop'>QUOTE(rickdm\";p=\"74154)</div>

Rick:

I think most cars would have trouble with the gravel road you've described. I've seen similar steep gravel hills on logging roads in NorthWest Ontario, and you need a 4WD.

Hmmm Hybrid Highlander ...

 

<div class='quotetop'>QUOTE(coloradospringsprius\";p=\"74203)</div>

I agree. For kicks I have tried flooring it in R and that thing zooms. Yes, I was in a very safe area while doing so, the yard at my hobby farm. It has a gravel drive and the Trac was constantly engaging.

 

My mistake on the "low torque".
Still, any front drive cars, no matter how much torque the engine has, cannot go up a steep hill if the friction is not there. The vehicle would reach a velocity and not going faster. The terminal velocity depends on the degree of the slope.

 

<div class='quotetop'>QUOTE(ceric\";p=\"74224)</div>

Yes, I agree on that point.

In the vast majority of situations a front wheel drive car provides much better useable traction, as most of the weight is on the drive wheels. You'll notice this in deep snow especially.

Weight transfer on a very steep gravel hill is another matter.

When I was in high school I visited a cousin in NW Ontario and we went partridge hunting on a logging road with his Mom's 1982 Dodge Omni. As soon as we drove down this awfully steep hill I turned to Steve and said "we're f*****, we'll never make it up."

We got a few birds then headed out. Steve even tried to take a run at the hill, but we got stuck around 2/3 of the way up. I was about ready to walk the 10 miles back to the highway and hope I wouldn't be eaten by a bear, but Steve just turned the Omni around and we *backed* up the hill. We made it too.

Though I should point out the clutch was fried by then. That poor car was in tough shape by the time we made it back to his house. I hear his Mom tore him a new one over it too.

I think in situations like that, a 4WD will provide clear advantages.

 

<div class='quotetop'>QUOTE(jayman\";p=\"74237)</div>

Yes, I agree on that point.[/b][/quote]
Double agreed. We'll just have to agree to agree.