e-4WD?

Unless there are shutters on the battery vents, heat will travel quicker to the battery compartment from the cabin than from the outside. The battery may not be in the cabin proper with the people, but it is within the cabin shell. Let's take the spare tire. In many cars it is in the trunk or cargo area. Enough though there is a cover of varying substance hiding it from everyday sight, it is still in the trunk, sitting on top of the sheet metal that forms the trunk's structural floor.

Like the spare tire being in the trunk, the traction battery is in the cabin. If it wasn't in the cabin, it could not be accessed easily from the cabin. If it was outside the cabin, like some spare tires and the fuel tank, it would be underneath the chassis floor of the trunk or cargo area, and completely exposed to the elements.

Cool info.
In the case of the AWD, top speed is limited to about 35mph. So the HSD is mostly in that ordinary mode during it's use.

They can't fly. Gravity is just allergic, and stays out of their way.

Which is a simplification, of course. The Sonata is a full hybrid, but still retains an automatic step transmission. It drops the efficiency robbing torque converter; the real source of that groups inefficiency.

 

I once wrote up this description of the Toyota transmission operation: Introduction to Prius Power Flow | PriusChat

Bob Wilson

 

No AWD For US-Market 2016 Toyota Prius - HybridCars.com

is it b/c we don't get any snow? or b/c it is not needed in California, biggest Prius market?

No AWD For US-Market 2016 Toyota Prius - HybridCars.com

 

That's an excellent classic thread although aspects of it (old MG1 rpm limits, no MG2 reduction gearing)
are necessarily a little out of date since it was written in 2007.

 

Not that I believed it would make any difference but I submitted a "Ask Toyota" request expressing my desire for a US E-Four Prius option. I receive a polite response "At this time, there are no announced plans to offer the E-Four (electronic four-wheel drive) system for the U.S. market, but your interest will be made available for review by the appropriate departments". Nothing new or insightful.

 

It's because the dealers can push people into the Rav4 hybrid with less effort in the US.

 

I'm still holding out hope.

"Industry sources believe Toyota may also unveil a new all-wheel drive variant, which could boost the car's appeal. However, this has not yet been confirmed."

2016 Toyota Prius: Redesign Info, Pricing, Release Date

 

Are they serious? Who the heck would be in the market for a Prius and end up with a Rav4? That's like being in the market for a steak and ending up with a quiche.

 

Perhaps the E-FOUR is not rugged enough for american drivers, and they are betaing it in Japan where drivers are less discerning. It smells fishy if it was a good system and they didn't release it here.

I would think a upcharge, a tow rating, and some added snow and rain traction would be great for the american market. Sure a big portion sell in california, and you don't want to drive a prius up to skiing, but ... there are lots of other potential US customers.

The problem with a drip drip drip roll out. They should have just delayed the information until tokyo motor show, and not done that strange no information show in vegas. I hope when tokyo finishes we get all the specs (other than final epa numbers).

 

Why not? I've taken my 2004 Prius up to the ski resorts. They plow the roads, you know.

 

Well, look at tow ratings in the US. The only brand that still has manufacturer tow ratings on their actual cars last time I checked was Volvo. Subaru has them on their wagons, but those might actually be crossing into the crossover/truck area. Otherwise, no other car is recommended for towing in the US, while the same models have a tow rating in other markets.

There are several reasons for this, and the fact that the public here has been convinced that you need a truck to tow is one of them. That and cheaper fuel makes in easier to upsell a car shopper to an SUV here than elsewhere. I don't think that the same reasoning could be applied to AWD. Ford didn't think they would lose many sales by not having AWD on the C-max when they cancelled the Escape hybrid.

 

I used to live in palo alto. You needed chains to go to tahoe or a rugged 4wd. They don't plow the roads enough. I don't think the prius would be a great ski car, although the hatch could carry the skiis better than lots of cars I did take up.

Again I think you are in violent agreement with me that if toyota is trying to sell the prius nation wide, and has a good awd system, they should sell it in the US. That is why I doubt they are confident with the awd system.

I don't think ford had developed a good e-awd system. The RXh/HiHy is mediocre at best. They were using the mechanical 4wd system of the escape, and the c-max didn't have one, not worth developing one for this.

I do think that tesla has engineered a really good e-awd system. It even is more efficient than 2wd. The tesla system does require a more powerful battery, but .... perhaps toyota could offer better E-FOUR for the US in the gen II prius phv (and make it better looking). Just a thought. 35 mph is actually fine for snow, but not great for helping tracrtion at higher speeds in the rain. Maybe the next gen Phv will be the upsell for americans if you want snow and rain traction.

 

The State Highway Department in Colorado plows the roads quite well. In 40 years of skiing, I've never once had a problem getting to the ski areas in a 2WD car.

I'd buy a 4WD Prius for places like my driveway, and the hills on my way to work. I have one spot where I have to start from a standing stop (a light) and turn left onto a 7% grade. In snow packed or icy conditions, it can take 30-40 seconds to get up to 15mph in my 2004.

 

Oh yes, I was talking about california ;-) when I have been to Colorado they have done a much better job. Hey we don't get snow in austin often, but when we do it closes the town. We don't even own our own snow plows, but wait for dallas to loan us some of theirs.

My cousin in upstate NY thought about a prius, but ended up with a fusion awd. They get lots of snow and even if they plow the roads, its nice on her steep driveway.

 

Yes, the Escape had mechanical AWD. That was part of the reason it had a better rep than the HiHy when actually used 'off road'. Barring a technical reason with their newer generation hybrid system or battery packaging, Ford could have used a mechanical AWD in the C-max hybrid. Their market research just showed that those interested in the Escape hybrid because of the AWD option would be fine with new Ecoboost Escape, and that there wasn't enough interest in AWD to offer it on the C-max.

When I started driving, AWD was still just an option on Subaru's, if offered at all. I admit in is nice to have for some times and places, and many say they want it, but like better fuel efficiency, it is a question of whether they are willing to pay for it. Just because Toyota will offer the E-Four in Japan doesn't it is no most to offer it in the US. It is a different drive train, and would require to be certified for emissions and fuel economy separate from the FWD model. They may have felt there wouldn't be enough buyers to warrant that cost, or they are saving it for the mid cycle refresh, or another or multiple reasons.

Is 35mph the top AWD speed for the current HiHy?
The E-Four almost seems to be a tacked on item. To rival mechanical AWD, an eAWD would need that larger battery, and/or a higher electrical output for serial operation from the hybrid drive.

 

For Gen3, Toyota was reluntant on offering solar roof and 17" rims due to weight issue. It may be that Prius would be pushed onto another weight class?

The same may be the case with E-Four.

 

If you need 4WD for traction, you shouldn't be going 35mph (much less over) anyway.

 

Well yes, which is true, because ford doesn't have a good implementation of e-awd. That worth it might be true if they had a good implementation. I don't know how well toyota has done on the Lexus NXh and Rav4 hybrid's e-awd, but this prius system is likely different from the description.

As we learned in ford's case and the 5 trim the EPA does not require new mileage testing. in any case they do offer e-awd on the nxh, rxh, HiHy (only option) and rav4 hybrid (only option). It shouldn't be difficult and I doubt emissions would increase greatly because they don't on those other cars.

35 mph was for the gen IV prius, I assume its higher for those other cars.

 

In what way does it sound different? Aside from the smaller rear motor, which is likely a result of the Prius being a smaller vehicle.

Who does have a good eAWD system? I agree on Tesla's, and the Acura RS hybrid likely is a contender. These are high end cars where compromising performance for cost isn't likely to happen. The RS has a V6 that may allow for better serial operation of the rear motors while still powering the front axle at higher speeds. It won't be a hybrid bought for fuel efficiency though.

Tesla gets a minor efficiency boost with the dual motors, but I think it's more prudent to say a two motor AWD system in a BEV won't see an efficiency hit like ICE and hybrid cars see. With PHVs, how good such an AWD system is will likely come down to battery size. I don't expect to see a two motor eAWD in a non-luxury plug in anytime soon, because of cost.

For a good eAWD system, which means one that can match a mechanical one in output and use, we need to be able to deliver more power to the electric motor only axle. A larger battery or higher output genset will do it, but these likely would provide little benefit to a 2WD hybrid model, and may even harm it in terms of efficiency. Making them part of the eAWD upgrade will drive the option price up.

So a mechanical AWD may actually be the best way of giving a hybrid the means if greater than full speed performance is desired.

Ford's rule bending was based on the two cars having the same weight and drive train for a loophole that was meant to allow the manufacturers save some cash by certifying just their, say, Crown Vic, and not also their Grand Marquis and Continental. Even if padding was added to have the same weight, I'd like to think that the EPA won't let someone slip a 2WD result for an AWD one under the same loophole.

I agree the operating emissions won't change much, but the fuel economy is measured from the carbon emitted. Skipping the NOx and HC testing won't save much on the cost of running the car through the test cycles to get an AWD window sticker MPG. The option is a must for SUVs offered for sale in the US, but not for cars. I think it's more about pushing sales to the Rav4 hybrid, and keeping the E-Four back for something new on a later model year, though.

The best I could find was a comment on a Lexus forum about AWD lock on turning off "at 35mph or so." Which doesn't say much when the Rav4 mechanical AWD can be locked on up to 25mph, and then it reverts to normal when the rear is slipping operation.

For those curious about the difference between 4WD and (mechanical)AWD, this is a nice primer, Four-Wheel Drive vs All-Wheel-Drive: Everything You Need to Know.

 

Uh...

Still live in the East Bay. When I was hitting Tahoe (pre-drought), I'd do it on a season pass (i.e. daytrips every weekend) on a RWD sport sedan on 45-section tires (the IS300 on all-seasons). I was a storm chaser, and relish getting there in the midst of a dump. I can also "brag" about getting stuck in sky-puking road closures and being stuck on the I-80/I-50 for 8 hours (always on the way back home) at least three times. 5 season passes in a row, might start again this year, but for snowshoeing and backcountry photography w/the significant other.

You don't need AWD for Tahoe.

The vast majority of people I saw in the ditches were in AWD cars, because they didn't understand that AWD does nothing to help you brake or increase cornering traction in the snow.

When I was in LA doing the same thing for three years with my cousin up to Big Bear, I was doing it in an AWD RX300. Sure, AWD keeps you off of chains for a little longer than 2WD. But it's rarely the snow that's the problem: it's the ice, for which you need chains (or Blizzaks, or studs) anyways. I can also attest to (unintentional) inertial-drifting a RX300.

The thing people do not seem to understand that is that in those conditions, you need to chain up all four wheels, at least in a conventional all-wheels-linked w/diffs and shafts AWD.

What you DO need to be a Tahoe regular is a snow shovel and a minimal knowledge of traction aides. If you're more of a regular than that, you would also keep an extra pair of chains beyond what is just needed. Chains DO wear and snap at inconvenient times (and sometimes take a chunk out of your fender liner), but you don't need to stay stranded or risk driving without them in conditions that necessitate them (and no, you can't run just one chain). Been there done that.

Disclaimer: have not taken the Prius into Tahoe snow yet (no snow, but did circumnavigate it this summer) The biggest question mark is not the drive configuration, but rather the LRR tires, regardless of all-season grading or not. The narrower contact patch of the 15" rimmed-version was chosen with this in mind.