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.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.
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.. . . 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.
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).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.
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.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: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.
http://www.dot.ca.gov/cttravel/chain-controls.htmlRequirement 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.
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.SageBrush said:If R1 the AWD with poor tyres is allowed to use the route but they have sacrificed safety for convenience.
Yes.GRA said:
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:Yes.GRA said:
The point here is that people are buying AWD and skipping winter tyres.
SageBrush said:Californians buy AWD and skip on winter tyres to a large degree.
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.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.
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.
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.
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.
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.RonDawg said: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.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.
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.
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