2017 Prius Prime PHEV

[LeftieBiker]

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.

[GRA]

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]

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.

[GRA]

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.

[jjeff]

^^^ 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).

[SageBrush]

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.

[GRA]

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).

[SageBrush]

I think you have your "R"s backwards; but more to the point you are mixing up regulatory compliance with actual safety.

[GRA]

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.

[SageBrush]

^^ 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.