MKV Toyota Supra Master Thread

[ssun30]

Interesting comment from Toyota that they are aiming 50% thermodynamic efficiency. I think they meant high performance drivetrain, since I believe their economy-oriented THS already passed that mark handily: the Prius should be close to 60%.

As a comparison Mercedes now makes a 50% efficient F1 engine, well it's not really fair since F1 engines also regenerate lots of energy from the huge turbo. I think Toyota does need an electrified turbocharger (they already have a few patent for it) to reach the 50% goal.

But again, all of this will be empty talk without a breakthrough in battery technology with these inefficient Li-ion batteries. Currently all the electrified sports cars come at a huge weight penalty. I don't think a hybrid sports car will be possible until mid-2020s, after TMC has a stable solid state EV production.

 

[Gecko]

Also from that article, it seems that the BMW I6 will be the engine of choice. So much for a Dynamic Force V6

 

[Joaquin Ruhi]

Interesting comment from Toyota that they are aiming 50% thermodynamic efficiency. I think they meant high performance drivetrain, since I believe their economy-oriented THS already passed that mark handily: the Prius should be close to 60%

No, the economy-oriented THS is nowhere close to that mark. Among the 10 zillion link-filled drafts I have for possible future Kaizen Factor stories is one on thermal efficiency. Here's a list of most of the information I have in there:

Toyota 2AR-FE 2.5-liter, 4-cylinder gas (RAV4, 7th-gen Camry): 35%
Toyota 2AR-FSE 2.5-liter, 4-cylinder w/D-4S hybrid (Lexus IS 300h): 38.5%
"Old" Toyota 2ZR-FXE 1.8-liter, 4-cylinder hybrid (3rd-gen Prius): 38.5%
Mazda Skyactiv G (gasoline) : roughly 40%
Toyota A25A-FKS Dynamic Force 2.5-liter, 4-cylinder gas (8th-gen Camry): 40%
Hyundai Kappa III/Blue 1.6-liter, 4-cylinder hybrid (Ioniq Hybrid): 40%
"New" Toyota 2ZR-FXE 1.8-liter, 4-cylinder hybrid (4th-gen Prius): slightly over 40%
Toyota A25A-FXS Dynamic Force 2.5-liter, 4-cylinder hybrid (8th-gen Camry): 41%
VW CBEA 2.0-liter, 4-cylinder diesel w/emissions-cheating software: 42.7%
AMG Project One hypercar: 1.6-liter turbo plug-in hybrid: 43%
Toyota 1GD-FTV 2.8-liter, 4-cylinder diesel: 44%
Toyota TS050 WEC racer: 2.4-liter V6 turbo hybrid: 45%

Mazda's upcoming Skyactiv-X (2-liter, 4-cylinder supercharged gasoline w/HCCI) predicts a 30% improvement in fuel economy vs the current Skyactiv-G, but I highly doubt that translates to a similar percentage increase in thermal efficiency to 52%. (I have yet to see thermal efficiency figures for Skyactiv-X)

Finally, worth citing is this passage from a Forbes article by Bertel Schmitt ( https://www.forbes.com/sites/bertel...tion-engine-will-survive-us-all/#159e00923a3d ):

Not too long ago, the typical gasoline automobile engine operated at around 25% efficiency. The theoretical maximum efficiency of a gasoline engine is said to be at around 56%, but in real life, (Toyota engineer Masashi) Hakariya thinks 50% will be the practical limit.

 

[supra93]

 

[ssun30]

No, the economy-oriented THS is nowhere close to that mark. Among the 10 zillion link-filled drafts I have for possible future Kaizen Factor stories is one on thermal efficiency. Here's a list of most of the information I have in there:

Toyota 2AR-FE 2.5-liter, 4-cylinder gas (RAV4, 7th-gen Camry): 35%
Toyota 2AR-FSE 2.5-liter, 4-cylinder w/D-4S hybrid (Lexus IS 300h): 38.5%
"Old" Toyota 2ZR-FXE 1.8-liter, 4-cylinder hybrid (3rd-gen Prius): 38.5%
Mazda Skyactiv G (gasoline) : roughly 40%
Toyota A25A-FKS Dynamic Force 2.5-liter, 4-cylinder gas (8th-gen Camry): 40%
Hyundai Kappa III/Blue 1.6-liter, 4-cylinder hybrid (Ioniq Hybrid): 40%
"New" Toyota 2ZR-FXE 1.8-liter, 4-cylinder hybrid (4th-gen Prius): slightly over 40%
Toyota A25A-FXS Dynamic Force 2.5-liter, 4-cylinder hybrid (8th-gen Camry): 41%
VW CBEA 2.0-liter, 4-cylinder diesel w/emissions-cheating software: 42.7%
AMG Project One hypercar: 1.6-liter turbo plug-in hybrid: 43%
Toyota 1GD-FTV 2.8-liter, 4-cylinder diesel: 44%
Toyota TS050 WEC racer: 2.4-liter V6 turbo hybrid: 45%

Mazda's upcoming Skyactiv-X (2-liter, 4-cylinder supercharged gasoline w/HCCI) predicts a 30% improvement in fuel economy vs the current Skyactiv-G, but I highly doubt that translates to a similar percentage increase in thermal efficiency to 52%. (I have yet to see thermal efficiency figures for Skyactiv-X)

Finally, worth citing is this passage from a Forbes article by Bertel Schmitt ( https://www.forbes.com/sites/bertel...tion-engine-will-survive-us-all/#159e00923a3d ):

You do realize the "45%" number refers to the overall efficiency of the entire THS-R drivetrain right? These "<40%" numbers you posted are the values for the ICE-component only.

Toyota just doesn't disclose the thermodynamic efficiency of the full hybrid package for road cars because it doesn't exist. It's incorrect to use the term "thermodynamic efficiency" for hybrids because the extra energy they get from kinetic/exhaust energy recovery do not count towards the calculation. Thermodynamic efficiency is the work done by the engine (at the crank) divided by the chemical energy released from fuel burn at steady-state, period. A steady-state thermodynamic efficiency only occurs when a hybrid drivetrain runs out of any electric energy, which just equals (or lower than, after factoring losses) the thermodynamic efficiency of the ICE. But in real world the "true overall efficiency" is heavily dependent on the usage scenario and battery SoC.

But I think both Toyota and Mercedes are just fine with mixing up different concepts because at the end of the day it doesn't matter: the MPG is the only thing that matters, and MPG means a lot in fuel flow-limited series like WEC and F1.

TL;DR: Basically a hybrid drivetrain has an "overall efficiency" that varies between the base efficiency of the ICE and infinity (pure EV mode). My "close to 60%" estimate is just a very unscientific estimate based on the fact that the 2018 Camry hybrid has 50% better MPG than the 2.5 gas-only trims.

 

[Joaquin Ruhi]

You do realize the "45%" number refers to the overall efficiency of the entire THS-R drivetrain right? These "<40%" numbers you posted are the values for the ICE-component only.

Toyota just doesn't disclose the thermodynamic efficiency of the full hybrid package for road cars because it doesn't exist. It's incorrect to use the term "thermodynamic efficiency" for hybrids because the extra energy they get from kinetic/exhaust energy recovery do not count towards the calculation. Thermodynamic efficiency is the work done by the engine (at the crank) divided by the chemical energy released from fuel burn at steady-state, period. A steady-state thermodynamic efficiency only occurs when a hybrid drivetrain runs out of any electric energy, which just equals (or lower than, after factoring losses) the thermodynamic efficiency of the ICE. But in real world the "true overall efficiency" is heavily dependent on the usage scenario and battery SoC.

But I think both Toyota and Mercedes are just fine with mixing up different concepts because at the end of the day it doesn't matter: the MPG is the only thing that matters, and MPG means a lot in fuel flow-limited series like WEC and F1.

TL;DR: Basically a hybrid drivetrain has an "overall efficiency" that varies between the base efficiency of the ICE and infinity (pure EV mode). My "close to 60%" estimate is just a very unscientific estimate based on the fact that the 2018 Camry hybrid has 50% better MPG than the 2.5 gas-only trims.

Interesting.

Believe me, I didn't pull those numbers I posted out of thin air. All those numbers have at least one source article and, in some cases, more than one source with matching numbers.

What I didn't know is that comparing thermal efficiency numbers between hybrid gasoline-electric and non-hybrids was such an apples-to-oranges comparison depending on what proportion of ICE vs batteries the hybrid is using at any given time. Thanks for your super-informative post.

BTW, most of those articles I read speak in terms of thermal efficiency. You refer to it as thermodynamic. Are the two terms synonymous and interchangeable? Or is there some sort of subtle difference between the two?

 

[ssun30]

Interesting.

Believe me, I didn't pull those numbers I posted out of thin air. All those numbers have at least one source article and, in some cases, more than one source with matching numbers.

What I didn't know is that comparing thermal efficiency numbers between hybrid gasoline-electric and non-hybrids was such an apples-to-oranges comparison depending on what proportion of ICE vs batteries the hybrid is using at any given time. Thanks for your super-informative post.

BTW, most of those articles I read speak in terms of thermal efficiency. You refer to it as thermodynamic. Are the two terms synonymous and interchangeable? Or is there some sort of subtle difference between the two?

I believe all the numbers you posted, and I was well aware of them even before the discussion. And I never said these numbers are invalid, but that they refer to a different concept to what Toyota said (that it has a 45% WEC "engine", it should really be called "power unit"). Sorry for any confusion my statement may have made, but the confusion is from Toyota/Mercedes to begin with.

Thermal efficiency and thermodynamic efficiency are exactly the same thing. But I tend to use the latter because the former does not apply to BEV/FCEVs (these don't generate work from "heat").

BTW, it is a very unsmart idea to publicly disclose the thermal efficiency of ICE engines because it serves nothing other than embarrassment. EVs are over 90% efficient and being "proud of" a 45% efficient ICE just gives Tesla a perfect target for a PR assault.

 

[supra93]

More spy shots, credit to @wilcoblok.

 

[spwolf]

No, the economy-oriented THS is nowhere close to that mark. Among the 10 zillion link-filled drafts I have for possible future Kaizen Factor stories is one on thermal efficiency. Here's a list of most of the information I have in there:

Toyota 2AR-FE 2.5-liter, 4-cylinder gas (RAV4, 7th-gen Camry): 35%
Toyota 2AR-FSE 2.5-liter, 4-cylinder w/D-4S hybrid (Lexus IS 300h): 38.5%
"Old" Toyota 2ZR-FXE 1.8-liter, 4-cylinder hybrid (3rd-gen Prius): 38.5%
Mazda Skyactiv G (gasoline) : roughly 40%
Toyota A25A-FKS Dynamic Force 2.5-liter, 4-cylinder gas (8th-gen Camry): 40%
Hyundai Kappa III/Blue 1.6-liter, 4-cylinder hybrid (Ioniq Hybrid): 40%
"New" Toyota 2ZR-FXE 1.8-liter, 4-cylinder hybrid (4th-gen Prius): slightly over 40%
Toyota A25A-FXS Dynamic Force 2.5-liter, 4-cylinder hybrid (8th-gen Camry): 41%
VW CBEA 2.0-liter, 4-cylinder diesel w/emissions-cheating software: 42.7%
AMG Project One hypercar: 1.6-liter turbo plug-in hybrid: 43%
Toyota 1GD-FTV 2.8-liter, 4-cylinder diesel: 44%
Toyota TS050 WEC racer: 2.4-liter V6 turbo hybrid: 45%

Mazda's upcoming Skyactiv-X (2-liter, 4-cylinder supercharged gasoline w/HCCI) predicts a 30% improvement in fuel economy vs the current Skyactiv-G, but I highly doubt that translates to a similar percentage increase in thermal efficiency to 52%. (I have yet to see thermal efficiency figures for Skyactiv-X)

Finally, worth citing is this passage from a Forbes article by Bertel Schmitt ( https://www.forbes.com/sites/bertel...tion-engine-will-survive-us-all/#159e00923a3d ):

Yeah, I dont think these numbers are apple to apple... Skyactive-X will not have anywhere close to Camry Hybrids efficiency at all - according to all the previews, it gets good mpg, but for regular petrol engine, it is not close to hybrid efficiency.

 

[supra93]

Another slightly reworked rendering.

 

[supra93]

Looks like they are using the Cayman as a benchmark.

 

[Gecko]

^Interesting, as they were partially benchmarking the Cayman with the 86...

 

[supra93]

Supposedly that is the 4 cylinder version.

 

[supra93]

New rendering

 

[supra93]

According to the forum's insider it will look like this. He reportedly saw what the car looked like on paper.

 

[spwolf]

that looks same as the blue one above, just less work put to make it more realistic looking.

 

[supra93]

Sorry I meant to say its suppose to look like this.

 

[supra93]

Here is a up close and personal view of the Supra. Skip to 6:23

Tire Sizes

Michelin Pilot Super Sport

Front : 255/40R18
Rear : 275/40R18

http://www.supramkv.com/threads/new-4k-video-of-supra.691/

 

[supra93]

 

[supra93]