Featured 2023 Prius spy shot

Cost is their guiding principle methinks. As long as people will buy new cars without spares, they’ll sell them.

 

That's a hot take, for sure...but not a correct one.

The Prius is Toyota's flagship vehicle for MPG gains, and they have always made evolutionary gains each in efficiency each generation throughout *all* aspects of the system. I'm convinced they will do this with the Gen5 HSD as well. As @Trollbait said above though...it will be more difficult this time, but an incremental gain will happen....probably due to increased ICE efficiency and possibly incremental gains in the electronics ( inverter, etc... ). I'm not sure we will see a 10% overall MPG gain though...

 

Weight reduction and improved aerodynamics (if possible) could help mpg. Another stake through the temp spare?

 

I'd bet against a 10% gain.

 

Its all about the numbers, we have a couple of facts to use, the long range big battery, (60 miles@ the Japanese cycle?) and the 2.0l dynamic force engine. Both can exceed 150hp, when combined there is a lot of power to spare.

The only real question is are they gonna funnel all this energy through the front wheels or are we going to get a nicely balanced awd.

 

Which can *still* be over 600 miles when you aren't on the interstate network.

With anything over about 40 miles of PHEV range, you don't need anything but a range-extender system. I still get 99+% of my in-town driving done on the Prius Prime's battery. With a bigger battery comes more available power and you don't need more power at all at that point, so there's no need for an engine connection to the wheel and no need for anything over covering average power.

That's a rotten way to look at it when different fuels have different conversion efficiencies - sometimes drastically different if you include electric (90% vs 40%, for example).

2000MPGe on my e-bike.

Toyota should put the 1L version of the G4 Prius engine in it, as a range extender, with no connection to the wheels, and a powerful four-wheel electric system (i.e. a Prime MG2 on each axle or similar capability). Electric systems are simply better than ICE systems at producing power on demand. ICE systems, if needed at all, are only needed for range extension (average power).

 

Interesting concept, and I see the logic you are suggesting. Has there been any rumblings at all about an entirely new drivetrain architecture? I haven’t heard anything that would suggest this.

I would find it hard to believe Toyota would move away from rock-solid reliability record and efficiency of HSD in the car that started it all; the engineering costs alone would make this a risky move, particularly in a model which has already had weaker sales in recent years compared to other Toyota hybrid vehicles. I think adding range and power to the existing HSD will reinvigorate interest in the Prius, and is the right move.

Just my opinion.

 

Neither have I.

The engineering for this is mostly trivial. It's been done before.

We have to stop burning fossil fuels as a part of our daily lives - desperately. A pure hybrid is just flat stupid with today's technology. The G4 should have been designed from day one as a PHEV and nothing else. This one should be designed as a series PHEV (range extender) with a BEV option, like the Ioniq.

 

Already addressed in #77 and #78.

 

Agree on both counts. I know other manufacturers including GM, BMW, Nissan and Mitsubishi (I think… and others) have/had Range Extender models so it wouldn’t be starting from scratch like ~10-15 years ago, but it would still be more work and cost for Toyota to develop their own implementation of this compared to leveraging the HSD they already have and is thoroughly real-world tested… that’s all I am saying.

And yes, every step we can take toward reducing fossil fuel usage is a good one. I look forward to my next vehicle having a much better AER, I have only been able to muster 13% EV usage in my PiP over it’s lifetime (160k KM by me over 6 years, 3 months), despite charging at every opportunity.. of course due to long commutes / road trips and not having charging at the office. Since I now work from home, my next PHEV with >40 mile range (new PP or RAV4 Prime), I am sure I will have 90%+ EV driving in this vehicle.

 

The range extension systems are there for emergency situations, not for daily basis driving.
These cannot be efficient enough, same goes to the dual motor transmissions that do not implement some kind of mechanical flow. Both Nissan and Toyota have these, (Toyota does not bother market it like some kind of innovation, because it is not) there are some advantages to the system though when used in city driving.
Toyotas power split is the killer app efficiency wise.

 

They're for road trips and rare cases.

It used to be.

I use electricity nearly 100% when I'm at home and gas 90% when out of town. That's the difference - the bifurcation of trip distance. Either my trips are under 20 miles or over 300 miles, for the most part.

 

Maybe we are talking on a different thing. I am not disagreeing on the bifurcation part.
Once you have an internal combustion engine running there are several methods to get the power to the wheels. Toyota has developed the most efficient way (by far) combining both mechanical and electrical energy flows. All other propulsion systems are inferior to the power split device, no matter how they call them.

 

But that's largely irrelevant *because* of the bifurcation.

The problem with their approach is that you end up with two systems, each having the power to give the vehicle the desired acceleration - the electrical system and the IC system. You don't need two! Instead of having a large IC engine with the power to propel the vehicle, you only need a small one to keep the battery charged on average. It's lower weight, it's lower cost, it has vastly reduced mechanical complexity, it's easier to package and place, and it takes up less room. Yes, it's less efficient but you're only supposed to use it rarely and the reduced weight all the rest of the time makes up for the lost efficiency during those few times it is used by reducing rolling and acceleration losses.

 

Honda's system is a modified series hybrid...correct? If I recall, Honda's system is very efficient al lower speeds. However, at higher speeds ( i.e. - USA freeways ), Toyota's HSD proved to be more efficient. I did a bunch of research when I was considering a hybrid accord at one point and the consensus at the time seemed to be that the hybrid Camry is more efficient at highway speed.

 

@Lee Jay Got your logic. Minimize the ice, to one cylinder if possible, and use it only when you run out of battery. It doesnt matter if this is not extra efficient because you already gain from simplicity, lower weight, etc.

@farmecologist the power split aka planetary gearbox is more efficient in both city and highway speeds. When in city it benefits from the lower hp of the mg1/mg2 combo, when in highway it benefits from the mechanical power flow. I dont see how Hondas implementation can compete on fuel efficiency.

 

Series hybrids have been around in locomotives from at least the 1960's. Like all the different systems, it has its pros and cons. The pros are in having the benefits of having a 100% EV drive train, and avoiding the costs of a mechanical transmission system. That's why trains switched it; cheaper to operate than a steam engine, and a diesel engine with mechanical transmission couldn't match the power output. The main con is in being less efficient at higher speeds.

As a range extender to a BEV designed car, it is really a no brainer. There is no messing with a mechanical transaxle, which can have drag losses on the drive train when the engine is off. Not having a mechanical connection to the wheels means more freedom in mounting the engine and generator. Ships are series hybrids because it allows installing the engine for the best center of gravity. For cars, it means making the best use of space with passengers, cargo, and battery.

Such a car will need an EV range approaching a hundred miles; more is better. Many people will be turned off by the lower hybrid efficiency on the highway. That is, in the beginning. In time, the public will realize they will be using very little fuel, even with lower efficiency, as firing up the engine is only a sometimes thing when the car has longer EV range.

Nissan had established their supply lines for their BEVs before introducing this. Starting with a BEV drive train means it was lower cost to develop. I don't think they've exported many, if any, outside of Japan. The poorer highway ratings will be worse on the tougher tests in other markets.

Getting just 40mpg on a trip done just once a week will more than likely result in less gas use than a 50mpg car that turns the engine on everyday. Design is compromise. It is why Honda's iMMS system does have a mechanical path for the engine, despite mostly working as a series hybrid. The Volt was the same. For a car with longer EV range, packaging the engine could be more important than getting the best hybrid efficiency.

Power-splits aren't without drawbacks. Full parallel systems get really close to their efficiency, and likely do so for a lower cost. That's because power-splits have to have an EV side powerful enough to work as a pure EV in order to work properly. Even the M/G1 needs to be more powerful than its starter and alternator duties entail, because it also works as the car's CVT. Copper is expensive compared to the steel and aluminum in an engine and transmission.

Power-splits are also lousy for work vehicles. Apparently, they, that is the transaxle, are too delicate. Everyone that came to market had lower tow ratings than the pure ICE model. Toyota doesn't even use it in the Tundra; that's a parallel system.

 

I don't think it needs to be that long. My analysis said 40 miles but it is application-dependent - if you have a longer commute or no charging at work (or both) you need more. If you live in flat-land and have everything close, you need less. 40 seems to cover 70-80% of people.