[FKHeath]

This is somewhat of a falsehood.

I have gas receipts (I log all my gas purchases in a note book) that say the same thing: 40+ MPG overall.

I don't know how you calculate your gas mileage, but I take the miles I traveled between fills and divide by the amount of gas I bought. That calculation is always near what the guess o meter MPG says. In the photo above 47.9 MPG. Can't fault a guy for rounding up and saying they got 48 MPG on a particular trip.

Immediately after l fill up, the Distance to Empty is often near 600 miles. I have never seen it at or above 600, but I do see it 560 to 580 -- and keep in mind that is the miles until the low fuel light comes on, not actually bone dry empty.

I'm not going to risk running out of gas, but there are times I could probably get 600 miles on a tank of gas.

 

[Rav4-lim]

On small drives, maybe even 1mi downhill, the mpg's will be high.
It's not always 47, and it will balance back out to reality.

It's only meaningful if you can take it fully charged full with gas on open flat hwy that has little head/tail winds. Drive it to empty. Then it's math, total mi / 14.5. That's the best it can do.

 

[Rav4-lim]

What makes you think RAV4 hybrid or Prime/PHEV is only capable of 507 miles on a full tank?

I did explain it.

When the batt needs charge it's stealing wheel power from engine to do that, so it's stealing MPG's directly from the gasoline. Plus, the vehicle can only go so far on a tank of gas, but because batt steals fuel you don't get all the gasoline into miles. The batt will steal way more gasoline for energy that regen braking will give.

It's rather simple conservation of energy.

The hybrid is not getting sustained 47mpg, not possible. 47x14.5=681mi, which is like 180mi more than advertised full tank range for hybrid.

Electric is more efficient, but to put say 10kWh into a batt, the engine needs to burn approx 25kWh of fuel, because ICE is at best 40% efficient.

 

[Tazio Nuvolari]

my hybrid gets 40+ MPG. Again, the ICE only can't do that.

I did once upon a time in perfect conditions on a long highway trip in my gas model 2021 AWD XLE. Normally I get around 27 to 28 MPG in combined highway & city with lots of hills.

 

[Dimitrij]

I did explain it.

When the batt needs charge it's stealing wheel power from engine to do that, so it's stealing MPG's directly from the gasoline. Plus, the vehicle can only go so far on a tank of gas, but because batt steals fuel you don't get all the gasoline into miles. The batt will steal way more gasoline for energy that regen braking will give.

It's rather simple conservation of energy.=ctric is more efficient, but to put say 10kWh into a batt, the engine needs to burn approx 25kWh of fuel, because ICE is at best 40% efficient.

You are correct in saying that in a R4H all energy, generated onboard, comes from burning gasoline.

However, it appears that your explanation of the battery "stealing wheel power" may be based on your assumption that R4H's powertrain operates all the time in series hybrid mode. In reality it doesn't.

Toyota's Hybrid Synergy Drive saves gasoline by recouping the energy of deceleration and going downhill, which would otherwise be wasted through friction- or engine braking. It also saves gasoline by allowing the ICE to stay in its optimal RPM range for longer, which improves the engine efficiency. Another avenue of savings is that to run AC when the car is stationary you don't need to idle the ICE all the time.

These of course do not prove that the R4H or a R4P in hybrid mode able to achieve 47 mpg, so for this we must turn to the anecdotal evidence. I am on my 4th Toyota hybrid (and 7th vehicle with electrified propulsion) and I have kept records of my fill ups for 10.5 years now. From my observations, 47 mph trips are rare, but they do occur, and I think the highest I clocked was a little above 50 mpg on my first Sienna. Again, rare, but not impossible.

On Fuelly 2021 R4H drivers reported over 700 fuel-ups with 47 mpg or better, and thousands of fuel-ups better than 40 mpg.

 

[Rav4-lim]

However, it appears that your explanation of the battery "stealing wheel power" may be based on your assumption that R4H's powertrain operates all the time in series hybrid mode. In reality it doesn't.

I made no such assumption. Toyota publishes hybrid batt distance, around 42mi. After that the batt is dead (well, lets just say you disconnect it from the system), after that you can only go so far on a tanks of gas. However, you cannot disconnect batt from the system, so at some point, many times perhaps, the ICE has to burn fuel to charge the batt. Doesn't really matter when the batt charges, but when it does charge it's stealing fuel from total MPG. The best MPG's from ICE will be freeway with low air wind, flat, and probably around 50-55mph. That's the best it can do.

"MPG" means nothing unless you define the test. I gave the test, full batt, full gas, flat freeway 50-55mph, stop and pee as needed. The overall MPG is nowhere close to 47. Be lucky to get 35MPG on that 500mi trip.

33-34mpg(max) is about reality (not a lab, real roads). The vehicle can't go 522mi when starting full tank full batt, 36mpg is a farce. My math is based on Toyota published range number. Range is just that, full tank full batt and how far it can go, "range".

Again, charging batt is wasting about 60% of gasoline used to charge the batt. 10kWh into batt will take 25kwH of gasoline (burned in ICE), and I am being conservative here, 40% efficient ICE is just north of max reality, plus gen losses, some heat, batt chemistry efficiency, etc.

The electric saves nothing. 25kWh from ICE to put 10kWh into batt (ICE is 40% efficient), then you can take 10kWh out of batt at say 98% efficiency, that math still says I used 25kWh of gasoline, 15KwH wasted into batt, 10kWh used for wheels (out of batt).

In the grand scheme of hybrid, not really saving all that much on gasoline, but you do get a better driving experience because acceleration from electric is way better than ICE.

Ever wonder why freeway speed is higher MPG than city? It's not stop-go of city. It's actually a function of engine rpm & load. ICE has a sweet spot rpm, and load is a function of kinematic friction (air, tires, trans, etc). Factor in city stop-go and that really hurts MPG.

All eV's are also wasteful, yet still better than ICE. If my electric rate is 10c/kWh and I fill my batt with 10kWh, it's not $1 cost, it's about $2 on my house meter? Why? because the transfer between utility to batt is 2x total (50% efficient), yep, putting 10kWh into batt will use about 20kWh of util power, beacause the to-vehicle charging gear is crap, super inefficient. You can't just look at the vehicle kWh meter, you have to place a kWh meter between util and the charging gear.

 

[Dimitrij]

I made no such assumption. Toyota publishes hybrid batt distance, around 42mi. After that the batt is dead (well, lets just say you disconnect it from the system), after that you can only go so far on a tanks of gas. However, you cannot disconnect batt from the system, so at some point, many times perhaps, the ICE has to burn fuel to charge the batt. Doesn't really matter when the batt charges, but when it does charge it's stealing fuel from total MPG. The best MPG's from ICE will be freeway with low air wind, flat, and probably around 50-55mph. That's the best it can do.

"MPG" means nothing unless you define the test. I gave the test, full batt, full gas, flat freeway 50-55mph, stop and pee as needed. The overall MPG is nowhere close to 47. Be lucky to get 35MPG on that 500mi trip.

33-34mpg(max) is about reality (not a lab, real roads). The vehicle can't go 522mi when starting full tank full batt, 36mpg is a farce. My math is based on Toyota published range number. Range is just that, full tank full batt and how far it can go, "range".

Again, charging batt is wasting about 60% of gasoline used to charge the batt. 10kWh into batt will take 25kwH of gasoline (burned in ICE), and I am being conservative here, 40% efficient ICE is just north of max reality, plus gen losses, some heat, batt chemistry efficiency, etc.

The electric saves nothing. 25kWh from ICE to put 10kWh into batt (ICE is 40% efficient), then you can take 10kWh out of batt at say 98% efficiency, that math still says I used 25kWh of gasoline, 15KwH wasted into batt, 10kWh used for wheels (out of batt).

In the grand scheme of hybrid, not really saving all that much on gasoline, but you do get a better driving experience because acceleration from electric is way better than ICE.

Ever wonder why freeway speed is higher MPG than city? It's not stop-go of city. It's actually a function of engine rpm & load. ICE has a sweet spot rpm, and load is a function of kinematic friction (air, tires, trans, etc). Factor in city stop-go and that really hurts MPG.

All eV's are also wasteful, yet still better than ICE. If my electric rate is 10c/kWh and I fill my batt with 10kWh, it's not $1 cost, it's about $2 on my house meter? Why? because the transfer between utility to batt is 2x total (50% efficient), yep, putting 10kWh into batt will use about 20kWh of util power, beacause the to-vehicle charging gear is crap, super inefficient. You can't just look at the vehicle kWh meter, you have to place a kWh meter between util and the charging gear.

It's for a reason that some people say Toyota's hybrid synergy drive has unbelievably high fuel efficiency .

I did once upon a time in perfect conditions on a long highway trip in my gas model 2021 AWD XLE. Normally I get around 27 to 28 MPG in combined highway & city with lots of hills.
[/QUOTE
Yep, that's quite possible. I did share this image somewhere else on the forum, but here it goes again: that's in Alaska, after a couple of hours of leisurely driving between Anchorage and Seward (gas only 2024 RAV4 AWD). Not quite 41.2, but close enough and way above the official figures.

 

[gregeusa]

OK, I should re-read all this over, so I may be making a mistake... but..

rav4-lim says that numbers are wrong because the gasoline used to recharge the battery is not properly recognized.

First, the system does NOT recharge the battery to full, i.e. 42 mile capacity..

Next, the statement ignores the reality that the car clearly prefers to recharge to battery to it's "working" level when it is advantages, it does not instantly run a full recharge on the battery when it is drained down.

Maybe I'm being overly simplistic, but it seems these things were not considered in rav4-lim's "calculations"

 

[Rav4-lim]

Next, the statement ignores the reality that the car clearly prefers to recharge to battery to it's "working" level when it is advantages, it does not instantly run a full recharge on the battery when it is drained down.

Maybe I'm being overly simplistic, but it seems these things were not considered in rav4-lim's "calculations"

It does not matter when the ice charges batt, or if the batt gets full or not, you have to realize that charging batt steals fuel from MPG. 10kWh into batt means 25kWh of fuel was used. The ice MUST burn fuel to charge the batt, and it does so at an incredible efficiency of just 40%.

My example gave best scenario for best MPG's.
Here's the ideal setup. You charge the batt to 100% at home by plugging it into the wall. Not really possible, but that's how we start "full" on batt and gas tank. That batt can move vehicle 42mi w/o ice, so that we don't steal fuel from ice and put it into batt, when the batt goes to zero you disconnect it, from there it's all ice until gasoline runs dry.

Any other scenario, like constant charging batt, discharging batt, charging batt, means you are wasting 60% of the gasoline used to create that energy going into the batt. On a long trip, which is no more than 1 tank of gasoline + 42mi, that batt may actually charge and discharge more than the initial 42mi a full batt can give you, but that means it's stealing fuel from the overall MPG's. There's no such thing as "gallon" in joules. We do know how much energy is in 1gal of gasoline, about 120MJ. 60% of that is wasted by ice no matter where it goes, the fuel must burn in ice at 40% efficiency. 14.5gal of gasoline provides approx 120MJ x 0.4 x 14.5 = 696MJ to use for motion, radio, electric seats, charging batt. That's all you get, the electric side of the system does not mysteriously turn that maximum available into something more. And although the electric side is say 98% efficient from batt to emotor, you wasted 60% of the gasoline used to charge the batt.

The best MPG possible, from full tank and full batt, is 1 full tank via ice + 42mi, all from 14.5 gal of fuel.
Again, all energy derived comes from ICE, no way around it.

"MPG" for hybrid is a gimmick. On a range test, I am willing to bet the hybrid Rav will go approx 40mi further than my ice-only Rav, when the hybrid batt starts off as full as it can be.

btw, I am using the 40% ice number, super conservative, usually found only in advanced diesel engines. Gasoline that is norm aspirated is 20-30%.

If anyone has any Rav that has gone more than 520mi on a full tank, lets see it.

 

[espos4]

It does not matter when the ice charges batt, or if the batt gets full or not, you have to realize that charging batt steals fuel from MPG. 10kWh into batt means 25kWh of fuel was used. The ice MUST burn fuel to charge the batt, and it does so at an incredible efficiency of just 40%.

My example gave best scenario for best MPG's.
Here's the ideal setup. You charge the batt to 100% at home by plugging it into the wall. Not really possible, but that's how we start "full" on batt and gas tank. That batt can move vehicle 42mi w/o ice, so that we don't steal fuel from ice and put it into batt, when the batt goes to zero you disconnect it, from there it's all ice until gasoline runs dry.

Any other scenario, like constant charging batt, discharging batt, charging batt, means you are wasting 60% of the gasoline used to create that energy going into the batt. On a long trip, which is no more than 1 tank of gasoline + 42mi, that batt may actually charge and discharge more than the initial 42mi a full batt can give you, but that means it's stealing fuel from the overall MPG's. There's no such thing as "gallon" in joules. We do know how much energy is in 1gal of gasoline, about 120MJ. 60% of that is wasted by ice no matter where it goes, the fuel must burn in ice at 40% efficiency. 14.5gal of gasoline provides approx 120MJ x 0.4 x 14.5 = 696MJ to use for motion, radio, electric seats, charging batt. That's all you get, the electric side of the system does not mysteriously turn that maximum available into something more. And although the electric side is say 98% efficient from batt to emotor, you wasted 60% of the gasoline used to charge the batt.

The best MPG possible, from full tank and full batt, is 1 full tank via ice + 42mi, all from 14.5 gal of fuel.
Again, all energy derived comes from ICE, no way around it.

"MPG" for hybrid is a gimmick. On a range test, I am willing to bet the hybrid Rav will go approx 40mi further than my ice-only Rav, when the hybrid batt starts off as full as it can be.

btw, I am using the 40% ice number, super conservative, usually found only in advanced diesel engines. Gasoline that is norm aspirated is 20-30%.

If anyone has any Rav that has gone more than 520mi on a full tank, lets see it.

You’ve convinced yourself that the hybrid system wastes gas but missed an important point. When the ice is running, it is usually in its most efficient rpm range. When this produces more power than needed, the excess power is used by mg1 to charge the battery. When this “efficient” rpm range doesn’t produce enough power to move the vehicle, battery power can supplement it.

Your argument that an ICE RAV4 has the same efficiency of a hybrid or Prime is tough to follow.

I routinely see 42-46 real world MPG in my 22 R4P on trips that I’ve intentionally done with the traction battery depleted. Basically a hybrid with a larger capacity.

 

[FKHeath]

It really doesn't matter where the gas is used and for what; doesn't matter if you have a hybrid or gas only. If gas is your only source of energy input, the bottom line is how far can you go on a gallon of gas.

As I posted above, I can go up to 48 miles on a gallon of gas. Not all the time, nor on all trips, but I have gotten mileage like that several times over the four years I have owned my RAV4 hybrid.

The Prime has another source of energy input: plug into a wall outlet. Thus it is possible to go more miles for the gas you buy than the hybrid.

 

[gregeusa]

so, reading this thread:

one person states that it's technically impossible to get more than 35 miles to the gallon

many people state from real experience about 10 mpg more.

oh drat, what to believe?

going to arizona in about a week, oh what will i do? (hand-wringing ensues)

 

[Big Daddy]

After reading this thread, I am getting the impression that owning a hybrid will cost me more money to purchase with slightly better gas mileage than I am getting now with my 2021 RAV4 XLE

 

[Tazio Nuvolari]

You’ve convinced yourself that the hybrid system wastes gas but missed an important point. When the ice is running, it is usually in its most efficient rpm range.

No it's not. The 5th gen ICE in both hybrid and gas models produces its maximum horsepower at 6600 RPMs. Maximum foot lbs. torque is produced at about 5000 RPMs. That is the engine's most "efficient" RPM. In the hybrid, when the gas engine kicks in it is usually trundling along at low RPMs --maybe 2000 to 3500 RPMs if even that. I doubt a hybrid would ever get into the 6000 RPM range even if you floored it.

 

[FKHeath]

Max horsepower is not max efficiency. At about 23 minutes of the well shared Weber State video of the RAV4 hybrid eCVT, he shows a chart of the engine efficiency. Keeping the engine in the region of that torque and RPM will produce the most efficiency, about 39%. Right at the beginning of the video, Prof. Kelley states that the Toyota hybrid gas engine has one of the highest brake thermal efficiencies of any engine.

That is one of the beauties of the eCVT: keeping, if possible, the gas engine in that most efficient region. (Also, the eight speed automatic in the gas only RAV4. The more gears you have, the better chance to have the engine in the best efficient region of operation). Yes, if you stomp on the gas, the engine will give more power and the RPMs will increase, but at the expense of efficiency.

 

[Rav4-lim]

You’ve convinced yourself that the hybrid system wastes gas but missed an important point. When the ice is running, it is usually in its most efficient rpm range. When this produces more power than needed, the excess power is used by mg1 to charge the battery.

Excess power? More jibberish.
There's no excess. ICE makes power, where that power goes is A+B thing.

Here's more proof that adding the hybrid end to ice wastes fuel.

Take an arbitrary amount of gasoline power, lets say 150kWh worth of fuel. The ice wastes 60% of that no matter where that burn goes. So that leaves input to ecvt at 60kWh. Of that 60 lets say you peel off 10 into batt, so 50 to wheels and 10 into batt for later use. Now the system wants e-power so it take 10kWh from batt, but the batt/moto system is probably in reality only around 90% efficient, so now you are wasting 10% of that stored 10kWh, you waste 1kWh.

So do the math, 150 - 90 - 1 = 59kWh. The batt/emotor wasted 1kWh, stealing that (wasting) from overall mpg.

If you hop in hybrid and every trip says you're getting 40 42 45mpg, all BS, because on 1 tank of gas you will NOT be driving 580mi, simply not possible.

It is possible to run ice in most efficient ways, but it does not really matter, even in best ways the ice can only be 40% efficient, which is over estimate for norm aspirated ice. High compression forced air ice can get 50+% efficient, but as you know, Rav aint that.

Ask another question, if the electric end was so great why have any mechanical linkage between ice and wheels at all? Why not connect motor directly to a generator, and from there run everything from electric. This is how locomotives work. In cars, having stored electric to dump fast when needed allows for the quick burst acceleration.

 

[Dimitrij]

No it's not. The 5th gen ICE in both hybrid and gas models produces its maximum horsepower at 6600 RPMs. Maximum foot lbs. torque is produced at about 5000 RPMs. That is the engine's most "efficient" RPM. In the hybrid, when the gas engine kicks in it is usually trundling along at low RPMs --maybe 2000 to 3500 RPMs if even that. I doubt a hybrid would ever get into the 6000 RPM range even if you floored it.

But it is.

When we look at efficiency, the focus should be on how many miles a vehicle can travel on a gallon of gasoline, not on max hp or lb-ft.

The A25A-FXS in normal driving circumstances spends most of its "ON" time between 1,500 and 2,500 rpm (my personal observation and with my driving style), which is where it operates most efficiently in the MPG terms. It can go up to 6,000 rpm, but - beyond satisfying one's curiosity - there isn't really need for it.

You’ve convinced yourself that the hybrid system wastes gas but missed an important point. When the ice is running, it is usually in its most efficient rpm range. When this produces more power than needed, the excess power is used by mg1 to charge the battery. When this “efficient” rpm range doesn’t produce enough power to move the vehicle, battery power can supplement it.

Your argument that an ICE RAV4 has the same efficiency of a hybrid or Prime is tough to follow.

I routinely see 42-46 real world MPG in my 22 R4P on trips that I’ve intentionally done with the traction battery depleted. Basically a hybrid with a larger capacity.

so, reading this thread:

one person states that it's technically impossible to get more than 35 miles to the gallon

many people state from real experience about 10 mpg more.

oh drat, what to believe?

going to arizona in about a week, oh what will i do? (hand-wringing ensues)

In this "one person's" defense, for someone who has never had a hybrid or researched the subject it could be hard to believe that a 4,000-lb vehicle can get anywhere near 40 mpg, let alone 45-50 mpg.

As someone said, "We sometimes don't understand certain ideas not because we are not smart enough, but because such ideas exist outside of the realm of our sensibilities".

Save travels to AZ! Post some scenery pix, if you would

After reading this thread, I am getting the impression that owning a hybrid will cost me more money to purchase with slightly better gas mileage than I am getting now with my 2021 RAV4 XLE

That would depend on how you use the car. If you drive at constant high speed on a level terrain you will not see any savings at all. But in real-life driving a Toyota hybrid driver should see a noticeable improvement on fuel efficiency. Here is a screenshot from fuelly.com, showing the peer-reported mpg figures for the Sienna. Looking at these figures, can you spot the MY when Sienna went from gas-only to hybrid? A bonus question: would 50% improvement be only slightly better, or perhaps a lot better?

 

[FKHeath]

Why not connect motor directly to a generator, and from there run everything from electric.

That is exactly how the first hybrid cars were built about 125 years ago by Ferdinand Porsche. Dr. Porsche is considered the inventor of the hybrid (gas/electric) car: https://en.wikipedia.org/wiki/Lohner–Porsche

Why not do that today? The Toyota eCVT was called the hybrid synergy drive for a reason: it can add the power from the gas engine and the power from an electric motor together to drive the wheels. Thus you can have more power at the wheels than a gas engine alone or an electric motor alone. The eCVT also allows you to keep the gas engine at the most efficient "sweet spot" of efficiency.

If you do the "locomotive" approach, gas engine drives a generator which drives the electric motor, you must have the generator/motors of the same power capability as the gas motor, i.e. much bigger than the RAV4 hybrid/Prime electric motors.

But the bottom line still remains: how far can the RAV4 hybrid go on a gallon of gas. I have shown that, at times, I get 48 MPG.

The gas tank is said to be 14 gallons, but the usable capacity is more like 12 or 13 gallons since there is a reserved space. Thus, I can go 12 X 48 = 576 miles on a tank of gas.

BTW, my son reports his Prius often does 60 MPG.

 

[espos4]

Excess power? More jibberish.
There's no excess. ICE makes power, where that power goes is A+B thing.

Here's more proof that adding the hybrid end to ice wastes fuel.

Take an arbitrary amount of gasoline power, lets say 150kWh worth of fuel. The ice wastes 60% of that no matter where that burn goes. So that leaves input to ecvt at 60kWh. Of that 60 lets say you peel off 10 into batt, so 50 to wheels and 10 into batt for later use. Now the system wants e-power so it take 10kWh from batt, but the batt/moto system is probably in reality only around 90% efficient, so now you are wasting 10% of that stored 10kWh, you waste 1kWh.

So do the math, 150 - 90 - 1 = 59kWh. The batt/emotor wasted 1kWh, stealing that (wasting) from overall mpg.

If you hop in hybrid and every trip says you're getting 40 42 45mpg, all BS, because on 1 tank of gas you will NOT be driving 580mi, simply not possible.

It is possible to run ice in most efficient ways, but it does not really matter, even in best ways the ice can only be 40% efficient, which is over estimate for norm aspirated ice. High compression forced air ice can get 50+% efficient, but as you know, Rav aint that.

Ask another question, if the electric end was so great why have any mechanical linkage between ice and wheels at all? Why not connect motor directly to a generator, and from there run everything from electric. This is how locomotives work. In cars, having stored electric to dump fast when needed allows for the quick burst acceleration.

That is exactly how the first hybrid cars were built about 125 years ago by Ferdinand Porsche. Dr. Porsche is considered the inventor of the hybrid (gas/electric) car: https://en.wikipedia.org/wiki/Lohner–Porsche

Why not do that today? The Toyota eCVT was called the hybrid synergy drive for a reason: it can add the power from the gas engine and the power from an electric motor together to drive the wheels. Thus you can have more power at the wheels than a gas engine alone or an electric motor alone. The eCVT also allows you to keep the gas engine at the most efficient "sweet spot" of efficiency.

If you do the "locomotive" approach, gas engine drives a generator which drives the electric motor, you must have the generator/motors of the same power capability as the gas motor, i.e. much bigger than the RAV4 hybrid/Prime electric motors.

But the bottom line still remains: how far can the RAV4 hybrid go on a gallon of gas. I have shown that, at times, I get 48 MPG.

The gas tank is said to be 14 gallons, but the usable capacity is more like 12 or 13 gallons since there is a reserved space. Thus, I can go 12 X 48 = 576 miles on a tank of gas.

BTW, my son reports his Prius often does 60 MPG.

Funny, we also have a Prius Prime, 2021

That routinely gets 58-62 mpg.
In the right climate, I’ve seen 72 mpg on highway trips, 70 mph seems to be a sweet spot for that car.
Also done with a depleted battery on purpose.

 

[Dimitrij]

That is exactly how the first hybrid cars were built about 125 years ago by Ferdinand Porsche. Dr. Porsche is considered the inventor of the hybrid (gas/electric) car: https://en.wikipedia.org/wiki/Lohner–Porsche

Why not do that today? The Toyota eCVT was called the hybrid synergy drive for a reason: it can add the power from the gas engine and the power from an electric motor together to drive the wheels. Thus you can have more power at the wheels than a gas engine alone or an electric motor alone. The eCVT also allows you to keep the gas engine at the most efficient "sweet spot" of efficiency.

If you do the "locomotive" approach, gas engine drives a generator which drives the electric motor, you must have the generator/motors of the same power capability as the gas motor, i.e. much bigger than the RAV4 hybrid/Prime electric motors.

But the bottom line still remains: how far can the RAV4 hybrid go on a gallon of gas. I have shown that, at times, I get 48 MPG.

The gas tank is said to be 14 gallons, but the usable capacity is more like 12 or 13 gallons since there is a reserved space. Thus, I can go 12 X 48 = 576 miles on a tank of gas.

BTW, my son reports his Prius often does 60 MPG.

The rear axle, though, does operate as a de facto series hybrid, doesn't it, because it has no mechanical connection to the ICE.

I guess thi

Funny, we also have a Prius Prime, 2021

That routinely gets 58-62 mpg.
In the right climate, I’ve seen 72 mpg on highway trips, 70 mph seems to be a sweet spot for that car.
Also done with a depleted battery on purpose.

You didn't finish the sentence that begins with "I guess thi .... "