5 ms·

This is the thing with good hybrids. The "gas pedal" becomes a "I want to go faster/slower" pedal, its position has zero impact on the RPM. As an anecdote: A

This is the thing with good hybrids. The "gas pedal" becomes a "I want to go faster/slower" pedal, its position has zero impact on the RPM. As an anecdote: A security company I know only buys Toyota Hybrids for their guards just because of that. They have a habit of driving cars like they stole them and normal ICE cars break down from that kind of abuse. Hybrids won't let you abuse them, they pick the RPM and you deal with it. (They also swap the passenger seat for a plastic box because the guards threw heavy crap like safety boxes on it, wearing down the seat in months)

vladvasiliu 1y ago
Do all Toyotas do that? I'm pretty sure that my dad's Corolla will rev the engine when I press the gas if the engine is already running. I'm also surprised for the first few minutes when I drive it how little "engine braking" it has (my habit is from riding a big motorbike).
- theshrike79 1y ago
  Dunno. My both Priuses did it and the company was specifically using the Yaris Hybrid. Both will rev on neutral, but when the gear selector is on Drive there is no link between the pedal and RPM.
  - bonzini 1y ago
    And on Brake it's even the opposite: above a certain speed, you press the accelerator and the RPM decreases to remove engine braking.
- trklausss 1y ago
  Depends on the configuration. If they are equipped with a CVT+electric engine on the shaft, then that's the case: they rev to the sweet spot (which on gas engines is 4000-5000 rpm on acceleration? Depending on expected engine load I assume) and the speed is controlled by hydraulic force applied on the CVT. With other hybrids: depends on the generator they have installed, but it matches the consumption in amps by the engine in order to "go" if it is not directly coupled with the transmission, or they just downshift to accelerate with help of the electric engine. I am assuming a lot here: Toyotas (specially RAV4) mount CVTs among others, assuming pure electric generator by the ICE or coupled to it... So it depends a lot on specific configuration.
  - taeric 1y ago
    Even CVTs will rev the engine if you floor it, no? They typically allow for wanting to be in a few sweet spots. I prefer to keep it near the max efficiency speed. That said, my wife is a bit more aggressive and spends more time in the max power mark. It has a predictable change on the MPG reported by the vehicle.
- MSFT_Edging 1y ago
  I know for a fact you can neutral-drop a prius. I know it's not exactly the same, but I was a teenager and curious, and you can rev them and shift into drive with some heel-toe finesse. Not sure if this works on the newer ones, this one was an early 2010s model.
  - kstrauser 1y ago
    Thank you for performing the experiment I didn’t even know I wanted to know the results of before now.
    - MSFT_Edging 1y ago
      I performed many experiments on that family prius and with complete honestly, my experiments weren't even in the top ten worst things that car survived. Trees, multiple motorcycles, final destination esque road debris, an accident that should have totalled it if not for an insurance mistake, leading to repairs worth more than the car. Three teenage drivers and two adult drivers with heavy feet. Not to mention many many hardware store runs hauling various sacks of yard materials, baby trees, lumber, etc. My favorite times were rallying on compacted un-plowed snow. The thin tires and light weight meant it absolutely shredded. It's my opinion that the Toyota Prius is one of the greatest vehicles ever built and they should be respected and feared.
      - kstrauser 1y ago
        That's an amazing testimony to its grit. I could stand to hear more of those stories over the appropriate beverage.
- adgjlsfhk1 1y ago
  it's possible that the engine rev is just the speakers. a lot of cars are doing fake engine sounds.
  - vladvasiliu 1y ago
    The dash has an RPM gauge which moves. Also, the noise is horrendous, not sure why they would have chosen that when they could have used a nicer-sounding tone. This is a tame small car, not something you'd buy to impress your friends.
- coryrc 1y ago
  They're programmed to rev in situations like that, because people are used to it. Under normal operation, RPM is decided by power needs. If you start accelerating on the freeway, for example, the engine might jump from 1100 RPM to 3000 RPM with just some pedal, while a manual transmission obviously changes very little.
RegnisGnaw 1y ago
The whole "pas pedal" becomes faster/slower (one pedal driving) is coming to an end. Its being banned as default in the world's largest EV market (and largest EV export country).
- taeric 1y ago
  I'm curious what you mean? I'm fairly confident the post you are responding to was only talking about newer transmissions. Which, I can't imagine those are going away?
  - RegnisGnaw 1y ago
    The post is talking about most people drive with BEV , which is one pedal driving. My Tesla does one pedal driving my default. China has banned "one pedal driving" as a default.
    - taeric 1y ago
      I took it to be people that are far more aggressive with the gas pedal than they really need to be. That is, it was more the heavy foot than it was letting off to brake. Regardless, your point stands. People that have gotten used to not directly using brakes to indicate you are slowing down is a dangerous thing with how reliant we are on the standard indications that you are slowing. All the more so if you need to rapidly lose a ton of speed, where even regenerative brakes often fall back to friction.
      - Sohcahtoa82 1y ago
        > People that have gotten used to not directly using brakes to indicate you are slowing down is a dangerous thing with how reliant we are on the standard indications that you are slowing. Most, if not all, EVs will light up the brake lights when you're slowing via regen braking as long as the deceleration rate is above a certain threshold. I know my Tesla does.
        1y ago
taeric 1y ago
This is less a hybrid thing and more a new transmission thing. It, of course, isn't free. The efficiency of a CVT is a good 10-20 percent lower than previous transmissions. That said, currently, the win from keeping the engine at either the max power or the max efficiency speed is substantial. There are some really good videos out there going over how newer CVTs work. Looks like some people are working on ones that are teeth driven, to reduce the loss from being free belt driven. Borderline magical stuff, all told. (Obviously, not magic magic. But very very impressive designs.)
- klaff 1y ago
  I have a Subaru (ten years old w/ >200k miles on it's chain-type CVT), and I thought the justification for it was that it was more efficient than previous systems. From a mechanical engineering standpoint, the Subaru CVT uses a fairly conventional lock-up torque converter at the input, but that gets locked as you pass something like 15-20 mph (once the lowest gear ratio is satisfactory w/o the torque converter function) and beyond that all shifting of the CVT is done w/ the torque converter locked. In addition, the clamping force of the sheaves is adjusted per the torque load of the transmission to minimize the frictional losses. Anyway I'm curious about data comparing efficiency of conventional and CVT automatics.
  - taeric 1y ago
    My understanding is that the overall system is more efficient. It is only the transmission that is less so. The videos online that look at various CVT systems is truly an amazing resource that I regret not having when I was younger. :D
    - klaff 1y ago
      If overall efficiency is what you see reflected in the EPA mileage numbers (or similar European tests), in what scenario would a lower efficiency transmission (lower Pout/Pin over some range of operating points?) lead to or even allow better overall efficiency?

vladvasiliu 1y ago

Do all Toyotas do that? I'm pretty sure that my dad's Corolla will rev the engine when I press the gas if the engine is already running. I'm also surprised for the first few minutes when I drive it how little "engine braking" it has (my habit is from riding a big motorbike).

theshrike79 1y ago
Dunno. My both Priuses did it and the company was specifically using the Yaris Hybrid. Both will rev on neutral, but when the gear selector is on Drive there is no link between the pedal and RPM.
- bonzini 1y ago
  And on Brake it's even the opposite: above a certain speed, you press the accelerator and the RPM decreases to remove engine braking.
trklausss 1y ago
Depends on the configuration. If they are equipped with a CVT+electric engine on the shaft, then that's the case: they rev to the sweet spot (which on gas engines is 4000-5000 rpm on acceleration? Depending on expected engine load I assume) and the speed is controlled by hydraulic force applied on the CVT. With other hybrids: depends on the generator they have installed, but it matches the consumption in amps by the engine in order to "go" if it is not directly coupled with the transmission, or they just downshift to accelerate with help of the electric engine. I am assuming a lot here: Toyotas (specially RAV4) mount CVTs among others, assuming pure electric generator by the ICE or coupled to it... So it depends a lot on specific configuration.
- taeric 1y ago
  Even CVTs will rev the engine if you floor it, no? They typically allow for wanting to be in a few sweet spots. I prefer to keep it near the max efficiency speed. That said, my wife is a bit more aggressive and spends more time in the max power mark. It has a predictable change on the MPG reported by the vehicle.
MSFT_Edging 1y ago
I know for a fact you can neutral-drop a prius. I know it's not exactly the same, but I was a teenager and curious, and you can rev them and shift into drive with some heel-toe finesse. Not sure if this works on the newer ones, this one was an early 2010s model.
- kstrauser 1y ago
  Thank you for performing the experiment I didn’t even know I wanted to know the results of before now.
  - MSFT_Edging 1y ago
    I performed many experiments on that family prius and with complete honestly, my experiments weren't even in the top ten worst things that car survived. Trees, multiple motorcycles, final destination esque road debris, an accident that should have totalled it if not for an insurance mistake, leading to repairs worth more than the car. Three teenage drivers and two adult drivers with heavy feet. Not to mention many many hardware store runs hauling various sacks of yard materials, baby trees, lumber, etc. My favorite times were rallying on compacted un-plowed snow. The thin tires and light weight meant it absolutely shredded. It's my opinion that the Toyota Prius is one of the greatest vehicles ever built and they should be respected and feared.
    - kstrauser 1y ago
      That's an amazing testimony to its grit. I could stand to hear more of those stories over the appropriate beverage.
adgjlsfhk1 1y ago
it's possible that the engine rev is just the speakers. a lot of cars are doing fake engine sounds.
- vladvasiliu 1y ago
  The dash has an RPM gauge which moves. Also, the noise is horrendous, not sure why they would have chosen that when they could have used a nicer-sounding tone. This is a tame small car, not something you'd buy to impress your friends.
coryrc 1y ago
They're programmed to rev in situations like that, because people are used to it. Under normal operation, RPM is decided by power needs. If you start accelerating on the freeway, for example, the engine might jump from 1100 RPM to 3000 RPM with just some pedal, while a manual transmission obviously changes very little.

RegnisGnaw 1y ago

The whole "pas pedal" becomes faster/slower (one pedal driving) is coming to an end. Its being banned as default in the world's largest EV market (and largest EV export country).

taeric 1y ago
I'm curious what you mean? I'm fairly confident the post you are responding to was only talking about newer transmissions. Which, I can't imagine those are going away?
- RegnisGnaw 1y ago
  The post is talking about most people drive with BEV , which is one pedal driving. My Tesla does one pedal driving my default. China has banned "one pedal driving" as a default.
  - taeric 1y ago
    I took it to be people that are far more aggressive with the gas pedal than they really need to be. That is, it was more the heavy foot than it was letting off to brake. Regardless, your point stands. People that have gotten used to not directly using brakes to indicate you are slowing down is a dangerous thing with how reliant we are on the standard indications that you are slowing. All the more so if you need to rapidly lose a ton of speed, where even regenerative brakes often fall back to friction.
    - Sohcahtoa82 1y ago
      > People that have gotten used to not directly using brakes to indicate you are slowing down is a dangerous thing with how reliant we are on the standard indications that you are slowing. Most, if not all, EVs will light up the brake lights when you're slowing via regen braking as long as the deceleration rate is above a certain threshold. I know my Tesla does.
      - 1y ago

taeric 1y ago

This is less a hybrid thing and more a new transmission thing. It, of course, isn't free. The efficiency of a CVT is a good 10-20 percent lower than previous transmissions. That said, currently, the win from keeping the engine at either the max power or the max efficiency speed is substantial. There are some really good videos out there going over how newer CVTs work. Looks like some people are working on ones that are teeth driven, to reduce the loss from being free belt driven. Borderline magical stuff, all told. (Obviously, not magic magic. But very very impressive designs.)

klaff 1y ago
I have a Subaru (ten years old w/ >200k miles on it's chain-type CVT), and I thought the justification for it was that it was more efficient than previous systems. From a mechanical engineering standpoint, the Subaru CVT uses a fairly conventional lock-up torque converter at the input, but that gets locked as you pass something like 15-20 mph (once the lowest gear ratio is satisfactory w/o the torque converter function) and beyond that all shifting of the CVT is done w/ the torque converter locked. In addition, the clamping force of the sheaves is adjusted per the torque load of the transmission to minimize the frictional losses. Anyway I'm curious about data comparing efficiency of conventional and CVT automatics.
- taeric 1y ago
  My understanding is that the overall system is more efficient. It is only the transmission that is less so. The videos online that look at various CVT systems is truly an amazing resource that I regret not having when I was younger. :D
  - klaff 1y ago
    If overall efficiency is what you see reflected in the EPA mileage numbers (or similar European tests), in what scenario would a lower efficiency transmission (lower Pout/Pin over some range of operating points?) lead to or even allow better overall efficiency?