Best way to traverse a mountain in a Prius?

That sounds more like a 4% grade to me. h/x = 930/25000 = 3.7%

 

3051 ft in 15.5 miles (This is like a climb to a ski area in AZ or NM)
? ~1kW per minute per mile?
If this was a Prime its EV range up hill would be?

Longest grade but not the steepest in my parts is in western MD. I-68@ Vocke Rd bridge (La Vale, MD) up to ridge west of Frostburg, MD. ~1750 ft in 9.1 miles

 

Misread earlier post. on EV kWh

The ICE going high output right before you get to the top of Murphy's Law Hill is about the only thing I don't like about the regular Prius HVs

If the OP slowed down to <25mph or? as he reached the crown of the hill could EV then be used?

FYI: Highway grades given by Google Earth include the ripple errors so they're not accurate.
http://media.galaxant.com/000/080/544/desktop-1412354778.jpg

 

There's not much upside in seeking EV on upgrades: you will burn through all the available charge really fast. We used to regularly park in the 4th level of a parking garage downtown. The relentless up-spiral at low speed always ran us down to two bars. I would try to avoid it by punching the gas pedal to intentionally run the engine, then coast to the next corner. But even with that it was difficult to avoid depletion to two bars.

I gave up worrying about it, but yeah: you will not make much headway up a steep grade in EV.

 

Why would you use B mode with disc brakes and dynamic braking? As I understand it B mode uses the engine to brake which uses gas. Yes, when the engine is on even in B mode it uses gas! My dealer tells me that they seldom have to do brake work on prius.

Just drive it and enjoy the ride!!!

 

The main use for B mode is to avoid, or at least postpone, a fully charged battery on a protracted downhill run, a hill long enough that the (fully charged) car is only using the friction brakes, and you still have miles of downhill grade to go.

This scenario can lead to burnt brakes, maybe even brake failure.

But yeah, only on long downhill runs, coming down mountains. England you're probably ok.

 

My Gen3 doesn't use gas when descending the mountains where I normally use it B mode. But if I forget to revert to D on the flats, then it does start using some fuel in cases where D mode would not.

I'll bet that your dealer never services brakes used in the Colorado mountain areas where FuelMiser drives.

 

I agree that this would add more value in the Prime, as I said in my post.
If we assume rather than one long hill, a series of shorter hills, then then benefits are much greater. That.s what I have in my part of the world.
Bottom line in my thinking is this. The hybrid system and it's regen braking either significantly helps the car's efficiency or it doesn't. As I assume we think it does, despite the battery size, then some software to help it do this better has to help.
Each individual instance of energy recovery is very small, but lots of instances of these small gains add up to a significant overall benefit.
Every time the car fails to recover energy because the battery is already full reduces this benefit and if that can be avoided more often it has to help.
What's the downside apart from development cost? And slightly increased battery use?
Each New Gen Prius is much more efficient than the last, and the overall increase is made up of many small increases. Added together they make a big difference.

Posted via the PriusChat mobile app.

 

Should that be labeled as the extra consumption to climb up that mountain, on top of the energy needed to travel the same distance at the same speed on a flat road?

A Gen1 PiP would empty its battery in that distance on level road, without any climb at all.

 

To the best of my knowledge, no one has done a temperature vs charge test with the LiON battery. Certainly this is a big NO with the NiMH battery.

Charging the NiMH battery is exothermic, it generates heat. So we always try to go up the mountain with minimal drain on the NiMH battery. Because once at the top, the car will put a charge back into the NiMH battery and heat it up. But I don't know the charge/discharge thermal characteristics of the LiON battery.

Until someone gathers some metrics, I would recommend going up the hill on the wonderful, 40% efficient engine even if it means taking a truck, climb lane. You won't stress the battery and that great engine will be doing exactly what it does best. But of course, it is your car.

GOOD LUCK!
Bob Wilson

 

I'm with you, RoadNoise. I too dwell on mileage minutia. I have a mountain pass to cross every day, and it pains me to have to use the hydraulic brakes so much. Plus there is very little compression braking from the engine, even when in B mode. I think one of the challenges of having a Prius is trying to wring as much mileage from each gallon of fuel possible.