Does the electric engine have more torque or gasoline?

Jaqueh2 · 07-19-2007, 03:20 PM

Because i would think its the gasoline engine since that is mainly used for torque situations (going up a hill, and getting from 30-60mph), but the electric seems to be good for accel and reverse only? am i wrong? I think that if the gas motor provides the torque the next prius should have an intelligent computer that can regulate the gas flow of the intake liters (1.6-2.3) so it can be fuel efficient when you are travelling fast. With that, when your going up a hill, the liters will go to 2.3 to make it more fuel efficient instead of the design now that just has blindly increasinig gas flow.

nwpa · 07-19-2007, 04:19 PM

The torque at RPM is what needs to be looked in thinking about your question.

The torque of the gas engine is listed at 82 lb-ft at 4200 RPM.

The torque of the traction motor is listed at 295 lb-ft at 0-1200 RPM.

The beauty of an electric motor is that it develops quite high torque at low rotational speeds. This is utilized in diesel-electric locomotives in getting a heavy train into motion. As the traction motors increase in RPM the total torque falls off.

The internal combustion engine has very little torque at low RPM, thus the need for either an automatic or manual gearbox to allow the RPM get up to give the wanted torque.

One of the beauties of the Prius is that the electric motor has good torque to get moving and the gas engine then takes over when it can operate at higher RPM.

If anyone finds errors in what I have said please point them out.

qbee42 · 07-19-2007, 04:39 PM

<div class='quotetop'>QUOTE(Perk @ Jul 19 2007, 04:19 PM) [snapback]481776[/snapback]</div>

Quote:

The torque at RPM is what needs to be looked in thinking about your question.

The torque of the gas engine is listed at 82 lb-ft at 4200 RPM.

The torque of the traction motor is listed at 295 lb-ft at 0-1200 RPM.

The beauty of an electric motor is that it develops quite high torque at low rotational speeds. This is utilized in diesel-electric locomotives in getting a heavy train into motion. As the traction motors increase in RPM the total torque falls off.

The internal combustion engine has very little torque at low RPM, thus the need for either an automatic or manual gearbox to allow the RPM get up to give the wanted torque.

One of the beauties of the Prius is that the electric motor has good torque to get moving and the gas engine then takes over when it can operate at higher RPM.

If anyone finds errors in what I have said please point them out.
[/b]

Said just fine. I will also add that the Prius already has several computers that do a very good job managing the balance between the ICE and the MGs.

Torque can be multiplied through gearing, but the gearing adds complexity and frictional losses. One of the beauties of an electric motor is that it can be used to directly drive a heavy load, without all of the normal transmission gears.

Tom

darelldd · 07-19-2007, 04:41 PM

Well answered already.

By any normal metric, an electric motor will give you more usable torque - for size, weight, cost, etc. You can gear it to offer the torque wherever you'd like. My EVs only have an electric motor of course. And without changing gears, I can spin the tires from a stop (at ZERO RPM and no clutch) in the same gear that I can cruise at 80mph. Show be the coffee-can-sized gas engine that can do that! (just getting your ICE to zero RPM while still "running" will be a good enough trick for me!)

nwpa · 07-19-2007, 07:57 PM

<div class='quotetop'>QUOTE(Perk @ Jul 19 2007, 04:19 PM) [snapback]481776[/snapback]</div>

Quote:

The torque at RPM is what needs to be looked in thinking about your question.

The torque of the gas engine is listed at 82 lb-ft at 4200 RPM.

The torque of the traction motor is listed at 295 lb-ft at 0-1200 RPM.

The beauty of an electric motor is that it develops quite high torque at low rotational speeds. This is utilized in diesel-electric locomotives in getting a heavy train into motion. As the traction motors increase in RPM the total torque falls off.

The internal combustion engine has very little torque at low RPM, thus the need for either an automatic or manual gearbox to allow the RPM get up to give the wanted torque.

One of the beauties of the Prius is that the electric motor has good torque to get moving and the gas engine then takes over when it can operate at higher RPM.

If anyone finds errors in what I have said please point them out.
[/b]

I would add that, in my opinion, Toyota has done a masterful job in blending the ICE and the electric motor(s) mechanically (PSD) and with the computer controls. I very much enjoy driving the Prius because the power transmission is so smooth.

donee · 07-19-2007, 08:11 PM

Hi All,

Good answers to the what the original poster meant to say. But a comment on the terminology. An engine is a device for converting heat energy into other useful forms of energy. Cars have an engine which converts the heat of combustion of the fuel into shaft energy (a shaft which will resist torque at some rpm).

A motor is any device used to create motion - MOTor > MOTion. The engine in a car is also a motor, besides the electric motors in the Prius.

That said, there are electric engines. Devices which convert heat energy directly into electricity. The Prius does not have any of these however. They are a hot ongoing topic of research, and recent advances have been made. When they become practical, the series hybrid car, with an electric engine prime-mover may be revolutionary.

alexstarfire · 07-19-2007, 09:18 PM

Maybe it's just me, but how does an ICE engine convert heat in any way? From what I understand about engines, which is very little believe you me, is that it converts the stored energy in the fuel to mechanical energy.

Same goes with the electric engine, except it converts the electric energy to mechanical energy.

Am I wrong?

Jaqueh2 · 07-19-2007, 09:29 PM

<div class='quotetop'>QUOTE(Perk @ Jul 19 2007, 04:57 PM) [snapback]481901[/snapback]</div>

Quote:

I would add that, in my opinion, Toyota has done a masterful job in blending the ICE and the electric motor(s) mechanically (PSD) and with the computer controls. I very much enjoy driving the Prius because the power transmission is so smooth.
[/b]

thanks for all of the answers, but while i admit the prius is smooth when doing normal things, but while going up the occasional SF hill, the prius does feel like it is going to die as the engine makes the loudest noise i have ever heard but there is no noticeable difference in speed. If one of you have ever been inside a mercedes as it breezes up the hill, you'll notice it barely makes any sounds and you can actually feel the power and torque as it goes, excuse me breezes, up the hill. And the gas usage is about the same as a prius heading up the hill at the same speeds.

Now mind you i love the prius, it is the best car i have ever been in, but its just them mountains.

David Beale · 07-19-2007, 09:33 PM

Any ICE converts heat energy into motion. It does so by the expansion of gas, the expansion is caused by heat. The heat is released during the chemical breakdown of the gasoline (it burns). As the gas expands it cools and the energy released is converted into mechanical motion (kinetic energy). The Atkinson cycle engine that we have in the Prius is particularly good at extracting the maximum amount of energy from the gas that is expanding. Due to the long expansion stroke.

An excellent description of the Prius THS II system is at:

http://www.toyota.co.jp/en/tech/envi...hs2/index.html

(thanks again, Ken, for the link).

The Prius actually adds the torque from the electric motor to the torque from the engine. Or you could state it the other way around.

Either way, one assists the other, and while the ICE tends to rev. a lot you do get a good kick in the pants when you depress the throttle.

The above link and the brochure for the car list the torque of the electric motor as 400 N-m (Newton metres), which, curiously, converts to 295 ft-lbs.

donee · 07-19-2007, 10:16 PM

<div class='quotetop'>QUOTE(Alexstarfire @ Jul 19 2007, 10:18 PM) [snapback]481936[/snapback]</div>

Quote:

Maybe it's just me, but how does an ICE engine convert heat in any way? From what I understand about engines, which is very little believe you me, is that it converts the stored energy in the fuel to mechanical energy.

Same goes with the electric engine, except it converts the electric energy to mechanical energy.
Am I wrong?
[/b]

Yes.

07-19-2007, 04:41 PM	#4
darelldd Prius is our Gas Guzzler Join Date: Jan 2006 Location: Northern CA Posts: 4,502 My Car: 2006 Prius Package: #6 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 10	Well answered already. By any normal metric, an electric motor will give you more usable torque - for size, weight, cost, etc. You can gear it to offer the torque wherever you'd like. My EVs only have an electric motor of course. And without changing gears, I can spin the tires from a stop (at ZERO RPM and no clutch) in the same gear that I can cruise at 80mph. Show be the coffee-can-sized gas engine that can do that! (just getting your ICE to zero RPM while still "running" will be a good enough trick for me!) __________________ -= Darell the EV Nut =- * EV Pages * Prius pages * PLEASE avoid sending me PMs!

07-19-2007, 09:33 PM	#9
David Beale Senior Member Join Date: Jul 2006 Location: Edmonton Alberta Posts: 1,551 My Car: 2007 Prius Package: B Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Any ICE converts heat energy into motion. It does so by the expansion of gas, the expansion is caused by heat. The heat is released during the chemical breakdown of the gasoline (it burns). As the gas expands it cools and the energy released is converted into mechanical motion (kinetic energy). The Atkinson cycle engine that we have in the Prius is particularly good at extracting the maximum amount of energy from the gas that is expanding. Due to the long expansion stroke. An excellent description of the Prius THS II system is at: http://www.toyota.co.jp/en/tech/envi...hs2/index.html (thanks again, Ken, for the link). The Prius actually adds the torque from the electric motor to the torque from the engine. Or you could state it the other way around. Either way, one assists the other, and while the ICE tends to rev. a lot you do get a good kick in the pants when you depress the throttle. The above link and the brochure for the car list the torque of the electric motor as 400 N-m (Newton metres), which, curiously, converts to 295 ft-lbs. __________________ Edmonton Alberta "Pearl" is a 2007 Driftwood Pearl Prius.

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07-19-2007, 03:20 PM	#1
Jaqueh2 Join Date: Mar 2007 Posts: 14 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Because i would think its the gasoline engine since that is mainly used for torque situations (going up a hill, and getting from 30-60mph), but the electric seems to be good for accel and reverse only? am i wrong? I think that if the gas motor provides the torque the next prius should have an intelligent computer that can regulate the gas flow of the intake liters (1.6-2.3) so it can be fuel efficient when you are travelling fast. With that, when your going up a hill, the liters will go to 2.3 to make it more fuel efficient instead of the design now that just has blindly increasinig gas flow.

07-19-2007, 04:19 PM	#2
nwpa Join Date: Sep 2006 Location: Erie PA Posts: 48 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	The torque at RPM is what needs to be looked in thinking about your question. The torque of the gas engine is listed at 82 lb-ft at 4200 RPM. The torque of the traction motor is listed at 295 lb-ft at 0-1200 RPM. The beauty of an electric motor is that it develops quite high torque at low rotational speeds. This is utilized in diesel-electric locomotives in getting a heavy train into motion. As the traction motors increase in RPM the total torque falls off. The internal combustion engine has very little torque at low RPM, thus the need for either an automatic or manual gearbox to allow the RPM get up to give the wanted torque. One of the beauties of the Prius is that the electric motor has good torque to get moving and the gas engine then takes over when it can operate at higher RPM. If anyone finds errors in what I have said please point them out.

07-19-2007, 08:11 PM	#6
donee Senior Member Join Date: Aug 2005 Location: Chicagoland Posts: 1,536 My Car: 2006 Prius Package: #2 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Hi All, Good answers to the what the original poster meant to say. But a comment on the terminology. An engine is a device for converting heat energy into other useful forms of energy. Cars have an engine which converts the heat of combustion of the fuel into shaft energy (a shaft which will resist torque at some rpm). A motor is any device used to create motion - MOTor > MOTion. The engine in a car is also a motor, besides the electric motors in the Prius. That said, there are electric engines. Devices which convert heat energy directly into electricity. The Prius does not have any of these however. They are a hot ongoing topic of research, and recent advances have been made. When they become practical, the series hybrid car, with an electric engine prime-mover may be revolutionary.

07-19-2007, 09:18 PM	#7
alexstarfire Join Date: Feb 2007 Posts: 218 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Maybe it's just me, but how does an ICE engine convert heat in any way? From what I understand about engines, which is very little believe you me, is that it converts the stored energy in the fuel to mechanical energy. Same goes with the electric engine, except it converts the electric energy to mechanical energy. Am I wrong?