2017 Prius Prime PHEV

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Looks like the AWD version will be non-plug-in and return to having a NiMH pack. Interesting. We haven't had any trouble with our Lithium pack in frigid weather.
 
LeftieBiker said:
Looks like the AWD version will be non-plug-in and return to having a NiMH pack. Interesting. We haven't had any trouble with our Lithium pack in frigid weather.
I wonder if there's no room for AWD on the Prime, because otherwise it would make no sense to not offer AWD on it. Or maybe they just haven't revealed it yet.
 
IIRC, the "new" NiMH battery will be under the rear seatback again, so they must have needed the space below the cargo compartment for the rear drive motor. Between the change in chemistry* and that, it seems a Prime with AWD will have to wait until the next version.


* NiMH packs do best if kept between 20% and 80%, and Toyota had great success with them by sticking to that. A smaller battery with less capacity per pound just isn't compatible with a PHEV - it would have EV range in the single digits.
 
Prius AWD-e, via GCR:
. . . But the system isn’t nearly as capable as the one you might encounter in Toyota’s utility vehicles, such as the Toyota RAV4 Hybrid or Highlander Hybrid, because its all-wheel drive system was conceived for getting out of snowy driveways, not necessarily for hauling the family up the mountain for a ski weekend.

The layout of the system—which adds a tiny 7-hp (5.3-kw) electric motor that can deliver 41 pound-feet of torque to the rear wheels—and the rationale behind it is mostly carried over from the Prius E-four, a model that has been sold in Japan for many years.

As Prius chief engineer Shoichi Kaneko explained to us last week at the LA Auto Show, it snows a lot in Japan. For snowy roads, front-wheel-drive vehicles have the hardest time with launch on an incline. So the first priority was to support a confident launch in stop-and-go traffic, uphill, on slippery roads.. . . .

Maintaining that 50-mpg mileage was a priority. Kaneko underscored that if you make it more of a full-time system, the amount of energy consumption increases. After going through some thorough optimization tests, Toyota found that the Prius got the best all-around efficiency by going with a lightweight, magnet-less (wound) motor—claimed to be a Toyota first—and skipping regeneration from the back wheels entirely.

The benefits of having a true “coast mode” for the rear motor when it wasn’t being used outweighed any brake-regeneration gains that might have potentially been made with a rear permanent-magnet motor, Kaneko said. . . .

Toyota has no plans to offer the AWD-e system on the Prius Prime, said Kaneko. Although when asked about the Subaru Crosstrek Hybrid, which uses Toyota’s hybrid transmission, fitted to a fully capable, even off-road capable all-wheel-drive system, Kaneko said that it reflects Subaru’s development priorities—and some efficiency decisions Toyota wouldn’t have mad.

But with Toyota continuing its work on electric vehicles, it’s likely that the automaker soon will find a way to show that full-time all-wheel drive and top efficiency aren’t mutually exclusive.
Shame about the Prime not offering it. I don't know that anyone thinks it needs to be full-time AWD, just have it kick in when needed.
 
^^^ agree. For me it would be nice to have AWD for the just half a dozen times/year I'd need it to make it up the moderate incline on our street. I mean I'm only talking about 500 feet but that 500 feet keeps both our Prius and Leaf(although the Leaf has a better chance) from making it to the top, and thus we have to wait the hours until the city comes by and plows and salts the road :(
As the article said, it doesn't have to have much power, just something and regen on the rear wheels wouldn't be needed at all, just something simple that provides power when needed and freewheels when not needed. Very disappointing they aren't talking about it for the Prime as when it comes time to replace our 10-year-old regular Prius, it would be a Prime or something totally different, maybe the Outlander PHEV, for sure our next ICE vehicle would have to have the ability to at least have a limited range on battery(20 miles min., 30+ would be nicer and would be willing to pay more for the option).
 
I thought about paying for AWD for my Tesla but I eventually realized that it was not a substitute for winter tyres; and with winter tyres it was a waste of money.
 
SageBrush said:
I thought about paying for AWD for my Tesla but I eventually realized that it was not a substitute for winter tyres; and with winter tyres it was a waste of money.
In Colorado you get R1 chain controls because people are used to driving on snowy/icy roads all winter and winter tires make sense, but as I've mentioned it's either R2 or R3 in California, and unless you're part of the tiny % of the population that lives above the snowline, no one has winter tires (just M+S all-season on the typical AWD car like my Subie). In short, for most people here AWD is primarily for convenience with regulatory compliance, not a performance need (bar the occasional use such as jjeff mentions).
 
I think you have your "R"s backwards; but more to the point you are mixing up regulatory compliance with actual safety.
 
SageBrush said:
I think you have your "R"s backwards; but more to the point you are mixing up regulatory compliance with actual safety.
No, R1 is chains or 2WD with snow tires or 4/AWD. R2 is chains or 4/AWD with snow tires (which includes M+S), and R3 is chains w/no exceptions. And no, I'm not mixing regulatory compliance with safety, I'm pointing out that the reason most people have 4/AWD here (assuming they ever drive in snow) is not for safety or performance, it's for compliance convenience - that's the case for me as well, as living at sea level and skiing a lot for 40+ years, the number of times 4/AWD has been necessary for me to get to my destination can be counted on the fingers of one hand (with a few to spare). The Highway Patrol simply skips R1 is most areas and goes direct to R2, even though there are many times when 2WD with snow tires is perfectly feasible. They set the controls for the lowest common denominator, which is someone who rarely (or never) drives on snow/ice, like most California skiers.
 
^^ You are not making any sense. Try again, since:

Californians buy AWD and skip on winter tyres to a large degree.
If the routes to the ski resorts require 'R2' then they are obliged to put on chains whether they have AWD or not.

If R1 the AWD with poor tyres is allowed to use the route but they have sacrificed safety for convenience.
 
SageBrush said:
^^ You are not making any sense. Try again, since:

Californians buy AWD and skip on winter tyres to a large degree.
If the routes to the ski resorts require 'R2' then they are obliged to put on chains whether they have AWD or not.
No:
Requirement 2 (R2): Chains or traction devices2 are required on all vehicles except four wheel/ all wheel drive vehicles with snow-tread tires on all four wheels.
NOTE: (Four wheel/all wheel drive vehicles must carry traction devices in chain control areas.)

Requirement 3 (R3): Chains or traction devices are required on all vehicles, no exceptions. . . .

Snow-tread Tires: The California Vehicle Code, Section 558 defines a snow-tread tire as follows, "A 'Snow-tread tire' is a tire which has a relatively deep and aggressive tread pattern compared with conventional passenger tread pattern". Snow-tread tires can be identified by examining the sidewall of the tire where the letters MS, M/S, M+S or the words MUD AND SNOW have been stamped into the sidewall.
http://www.dot.ca.gov/cttravel/chain-controls.html

SageBrush said:
If R1 the AWD with poor tyres is allowed to use the route but they have sacrificed safety for convenience.
Sure, the question is how much. For example, in Yosemite Valley the roads make a 14 mile loop. Often, they'll be completely dry except for two locations extending about 100 yards each, where frost//snow/ice can build or stick longer. Either can easily be driven without chains, even on bald tires. I know this because I once wrecked a set of rear tires and chains on my (RWD) Impala while I was staying there for a week, as they had chain controls up for the entire valley loop even though these were the only two patches of road that weren't completely dry. After I wore a chain cross link away on one of them (the other chain's cross links were getting pretty close) and spent a half hour under the car at night untangling the first chain (it had wrapped itself around the axle when it broke), I removed the other one before it broke and I had to go through a second untangling, and proceeded to exit the valley climbing 2,000 feet in the process over mostly snow covered roads on bald rear tires. I took my time, but had zero issues. The tires had been in good shape when I arrived, but were bald after a week of chains grinding on them on pavement. I would have relished having a ranger stop me, because I was furious and would have loved to tell them just what I thought of their chain control practices.

Even if they don't have controls up for the entire valley loop, they may put them up for just these two spots, which is ludicrous - one's completely flat, and the other's a slight curve on a very gentle downhill, where you're already driving slowly - I have no doubt that an idiot could get in trouble at either, but they can do that anywhere. Even when the Valley roads are snow covered they're almost entirely flat, and anyone paying even the slightest attention can drive them sans chains on regular tire, never mind snow tires. Given the option of dealing with that or similar issues (parts of I-80 and SR-120 can dip in and out of bare pavement for substantial distances) on a regular basis, or just buying a car with 4/AWD with M+S tires to avoid the hassle, which do you think most skiers here choose? You rarely see R3 here, because instead of putting that up they're more likely to just close the road. Although I've always carried chains in my 4/AWD cars, I think I've only had to use them (and was glad to have them) once in 30 years.
 
SageBrush said:
GRA said:
Yes.
The point here is that people are buying AWD and skipping winter tyres.
Because we simply don't need them - as I mentioned, most people don't live where snow's on the ground most of the winter, so putting full blown winter tires on and driving around with them on bare pavement for 4 months or more makes no sense. All-season M+S tires are legal, adequately safe, last longer, are quieter, get better mileage and don't require buying an extra set of tires, storing them and having them mounted/demounted every year, so why would people opt for the latter when they get little benefit? It would be different if you lived above the snow line, but only a small number of people here do compared to the much larger numbers who just visit occasionally.
 
SageBrush said:
Californians buy AWD and skip on winter tyres to a large degree.

In addition to what GRA posted, winter tires are not designed to be operated in warmer weather conditions, which is not unusual in the more populated parts of this state (it's currently 64 degrees F here in LA, but highs of 80's and even 90's are not unheard of even in January). Winter tires driven in such weather conditions will wear out quicker, but more importantly almost all winter tires have subpar traction in the dry and even the wet (but well above freezing point) when compared to even an all-season. Exceptions are the newest so-called "All Weather" tires like the Michelin CrossClimate or Vredestein Quatrac 5.

So we make do with all seasons, because it makes no sense to swap them for true winter tires for the occasional weekend in Tahoe or Mammoth or Big Bear. And until I get to a high enough elevation for the temperature to drop to that tire's design specification, I'll be driving with reduced grip.

Jason from Engineering Explained shows why (skip to 2:00 if you just want to see the results):

https://www.youtube.com/watch?v=Lrz14n4vVkQ

Note that Jason performed that test at 63 F, hardly "summer" and there was already significant degradation in the winter tire's braking performance as compared to the all season tire.
 
It will be interesting to see if the Toyo Celsius 4 season Winter tires solve the above problem. They would be best for those who travel to the mountains a LOT, of course.
 
RonDawg said:
<snip> So we make do with all seasons, because it makes no sense to swap them for true winter tires for the occasional weekend in Tahoe or Mammoth or Big Bear. And until I get to a high enough elevation for the temperature to drop to that tire's design specification, I'll be driving with reduced grip. . . .

Note that Jason performed that test at 63 F, hardly "summer" and there was already significant degradation in the winter tire's braking performance as compared to the all season tire.
Yup (cool and sunny in the Bay Area today, highs in the upper '50s, lows '30s - '40s). Living close to an ocean rather than in the center of a continental landmass really moderates the temps. Blue Canyon on I-80 (5,282 feet) is currently 43 deg., with the overnight low (partly cloudy) forecast to be 35. Even Truckee, which is just a few miles from the spot where the lowest temp ever recorded in California occurred (Boca, -45 in 1937, and I was up there once when that same spot hit -37) is 39 right now, and the overnight low is forecast to be 21.
 
GRA said:
Even if they don't have controls up for the entire valley loop, they may put them up for just these two spots, which is ludicrous - one's completely flat, and the other's a slight curve on a very gentle downhill, where you're already driving slowly - I have no doubt that an idiot could get in trouble at either, but they can do that anywhere. Even when the Valley roads are snow covered they're almost entirely flat, and anyone paying even the slightest attention can drive them sans chains on regular tire, never mind snow tires.

The first winter I had my Alltrack, the southern Sierras got a record amount of snowfall. So 395 had R2 chain controls from basically just outside Bishop, going to pretty much the NV border.

While there were some treacherous sections, particularly just north of the Mammoth Lakes turnoff, there were many long and dry patches as well. But Caltrans is of the belief to "chain up early" and for every mile you actually had slick conditions, there were 2 or perhaps even 5 miles of perfectly dry roadway. And if you didn't have AWD with the legally-specified tires, you were forced to chain up and endure the noise and vibration as well as tearing up the asphalt.

Although I've always carried chains in my 4/AWD cars, I think I've only had to use them (and was glad to have them) once in 30 years.

Technically it's the law in California to carry chains in your vehicle even if yours is exempt from chains in R2 conditions (used to be that way with R1, but that seems to have been eliminated). Even with 4WD/AWD I've had to show that I had chains in my vehicle, and one time at a checkpoint going up to Big Bear I saw a Toyota 4X4 being ordered to turn around by the CHP officer because the driver didn't bring chains. Annoying, because I bought a set for my Toyota 4X4 that NEVER got used in the 7 years I owned it...and those suckers aren't cheap!
 
LeftieBiker said:
It will be interesting to see in the Toyo Celsius 4 season Winter tires solve the above problem. They would be best for those who travel to the mountains a LOT, of course.

This review seems to like them a lot: https://www.autotrader.ca/newsfeatures/20180308/long-term-tire-test-toyo-celsius-all-weather-tires-part-two/
 
RonDawg said:
GRA said:
Although I've always carried chains in my 4/AWD cars, I think I've only had to use them (and was glad to have them) once in 30 years.
Technically it's the law in California to carry chains in your vehicle even if yours is exempt from chains in R2 conditions (used to be that way with R1, but that seems to have been eliminated). Even with 4WD/AWD I've had to show that I had chains in my vehicle, and one time at a checkpoint going up to Big Bear I saw a Toyota 4X4 being ordered to turn around by the CHP officer because the driver didn't bring chains.
I carry them for both reasons but I've never had to show them, probably because I rarely go up to Tahoe anymore but usually ski in Yosemite, and I'm normally coming into the park at night after the tourists are off the roads - the rangers are few and far between. Course, the first ski trip I took my first Subie up to Yosemite I got overconfident and slid off a turn and over a small pine tree, doing about $1,300 worth of damage and learning that 4WD doesn't help you brake or turn. That lesson's 30 years old now, and I've never had an accident since.

Sounds like 395's as bad as I-80 as far as chains. I could see there might be problems over Deadman summit (8,047') north of Mammoth, although I'd think descending Sherwin summit (6,426) north of Bishop going south would be worse if there's snow.
 
GRA said:
Sounds like 395's as bad as I-80 as far as chains. I could see there might be problems over Deadman summit (8,047') north of Mammoth, although I'd think descending Sherwin summit (6,426) north of Bishop going south would be worse if there's snow.

The section between the Mammoth Lakes turnoff and Deadman Summit is worse because that stretch of roadway is perpetually shaded by trees. Very scenic, but in winter can be treacherous as the snow takes forever to melt. It often will have R2 restrictions well after even R1 is lifted elsewhere.

Sherwin Grade is steeper but snow/ice melt quickly as it's almost all exposed to the sun.
 
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