Levi

Expert
Messages
1,603
Reactions
1,921
@Levi , I was the dreamer of this website if you remember, but honestly, that's not even in my dream, to much to dream about, Toyota won't ever tune this engine hard for the sake of longevity, that was obvious already with the MK-3 Tundra
GR Yaris G16E-GTS tells a different story, and even this one has reserve. So for the right product, TMC can do anything that deserves to be world class. Note I wrote V35A-GTS, not FTS. Or would it also be V35E? Anyway, look at 2UR-FSE tune for longevity, and see how 2UR-GSE easily makes 500 PS if not for emissions stuff.
 

mediumhot

Follower
Messages
311
Reactions
480
Do you guys remember the IS F rumor of V6 turbo hybrid? If there is a new gen IS/RC, the F could very well get a different tune of V6 turbo hybrid that we have in the Tundra, and will definitely also be in Sequoia, Landcruiser and LX.

Doesn't an AWD IS F with V35A-GTS hybrid, 550-600 PS combined and 700-750 Nm sound like something plausible?

V6TT Hybrid is a truck engine. I don't think it will ever see light of the day in midsize car or smaller.
 

Levi

Expert
Messages
1,603
Reactions
1,921
V6TT Hybrid is a truck engine. I don't think it will ever see light of the day in midsize car or smaller.
what makes it a truck engine? by that reasoning V6TT is a sedan engine. I am surprised the LS did not come with V6TT hybrid above, but rather NAV6 hybrid under. LS 600h was LS 460 with hybrid. If V6TT can replace NAV8, so V6TT hybrid should replace NAV8 hybrid. How did they think LS 500h would sell? This engine is for GS, not even for LC, should rather have been in RC/IS, because the NAI4 hybrid is good instead of a diesel, but it lacks the "S" of "Sport".

I know the IS 500 is out only now, but maybe we can start the "IS discontinued" thread too, to be accustomed to the pain as with "GS discontinued". 1IS was the first small sedan. 2IS, IS-F saved the day, but it could have been better if Lexus made a proper coupe of it, a wagon for Europe. 3IS was faded fast, but this time RC saved the day. I don't understand why Lexus needs to "save the day". Either do it right from the beginning or scrape it for good. See V8TT.
 
Messages
7
Reactions
9
what makes it a truck engine? by that reasoning V6TT is a sedan engine. I am surprised the LS did not come with V6TT hybrid above, but rather NAV6 hybrid under. LS 600h was LS 460 with hybrid. If V6TT can replace NAV8, so V6TT hybrid should replace NAV8 hybrid. How did they think LS 500h would sell? This engine is for GS, not even for LC, should rather have been in RC/IS, because the NAI4 hybrid is good instead of a diesel, but it lacks the "S" of "Sport".

I know the IS 500 is out only now, but maybe we can start the "IS discontinued" thread too, to be accustomed to the pain as with "GS discontinued". 1IS was the first small sedan. 2IS, IS-F saved the day, but it could have been better if Lexus made a proper coupe of it, a wagon for Europe. 3IS was faded fast, but this time RC saved the day. I don't understand why Lexus needs to "save the day". Either do it right from the beginning or scrape it for good. See V8TT.
I agree with you. It would’ve been really nice if the IS and RC lineups mirrored each other. But, the IS500 F sport Performance having the same engine/transmission as the RCF (which is one tier above) is really confusing and, in my opinion, shows poor planning. In its competitors, the 3/4 series, A4/A5, and C class sedan/coupe mirror each other.

In a perfect world, it would’ve made sense if there was the IS/RC 300 AWD with the detuned 3.5 V6, IS/RC 350 with the 2.4T, IS/RC 500 F Sport Performance with the V35, and the ISF/RCF with the V8 or V35+Hybrid.

My perfect Lexus would be the current design IS (with rear LED turn signals), V35, the LC derived 10 speed, and a torque vectoring AWD system (similar to what can be found in the GR Yaris). It will never happen, but it’s nice to dream.
 

Sulu

Admirer
Messages
563
Reactions
803
V6TT Hybrid is a truck engine. I don't think it will ever see light of the day in midsize car or smaller.
what makes it a truck engine? by that reasoning V6TT is a sedan engine.
The V6TT Hybrid powertrain in the new Tundra has a completely different hybrid system (and transmission) than the hybrids in Toyota and Lexus cars. It was designed for use in trucks and consists of an electric motor sandwiched between the engine and the otherwise normal 10-speed automatic transmission; the hybrid systems in the cars replaces the normal transmission with an eCVT Power Split Device transmission (which is unlike any normal automatic transmission).

The Tundra's hybrid powertrain is only available in trucks right now with no word that it will be adapted for use in RWD cars.
 

ssun30

Expert
Messages
2,236
Reactions
5,224
The V6TT Hybrid powertrain in the new Tundra has a completely different hybrid system (and transmission) than the hybrids in Toyota and Lexus cars. It was designed for use in trucks and consists of an electric motor sandwiched between the engine and the otherwise normal 10-speed automatic transmission; the hybrid systems in the cars replaces the normal transmission with an eCVT Power Split Device transmission (which is unlike any normal automatic transmission).

The Tundra's hybrid powertrain is only available in trucks right now with no word that it will be adapted for use in RWD cars.
There's nothing that prevents a P2 hybrid system to be used in a car. It's actually more compact than the multi-stage hybrid so it could fit in the LS/LC.

The Type 21 V35 in the Tundra and Type 17 in the LS500 are indeed different. The Type 17 is more sophisticated while the Type 21 is more for simplicity and durability. The Type 17 has better air flow thanks to double intercoolers, double intake manifolds and slightly larger turbos.
 

spwolf

Expert
Messages
3,124
Reactions
3,217
There's nothing that prevents a P2 hybrid system to be used in a car. It's actually more compact than the multi-stage hybrid so it could fit in the LS/LC.

nothing that prevents it other than better performance of HSD in non truck applications.
 

ssun30

Expert
Messages
2,236
Reactions
5,224
nothing that prevents it other than better performance of HSD in non truck applications.
How many times do I need to say PS hybrid does not scale up well past 300kW? Multi-stage was very well-engineered but not a good idea to begin with. One can argue with more advanced motors and PCU, PS can eventually scale up to 400kW, but P2 can be scaled to 750kW now.

The fact that most of the power goes through the electrical pathway is why PS is not good for high continuous load which includes truck and performance cars. PS is good for the exact opposite: variable load with short peak and mostly idle like urban driving.
 

carguy420

Follower
Messages
293
Reactions
357
I'm probably going to get shot for saying this but I never really liked the PS hybrid, no doubt they get great fuel economy especially in stop and go traffic, but the performance and driving feel leaves much to be desired IMO, they just don't quite have that direct and punchcy feel when you step on the throttle. Honestly kinda want Toyota to implement P2 hybrid into their regular cars. Btw would P2 hybrid actually be cheaper than PS hybrid since it's much simpler than PS?
 

qtb007

Fan
Messages
31
Reactions
36
I'm probably going to get shot for saying this but I never really liked the PS hybrid, no doubt they get great fuel economy especially in stop and go traffic, but the performance and driving feel leaves much to be desired IMO, they just don't quite have that direct and punchcy feel when you step on the throttle. Honestly kinda want Toyota to implement P2 hybrid into their regular cars. Btw would P2 hybrid actually be cheaper than PS hybrid since it's much simpler than PS?
I'd wager that there are wayyyyy fewer moving parts in the parallel style hybrids because you drop the complex multi-gear transmission for relatively simple dual motors attached to a torque split device. Multi-gear transmissions are super complex, so while the Tundra is simple in concept, it has an ultra complex 10 speed auto parked between the housing motor and transfer case.

I think that the P2 makes a lot of sense in longitudinal drivetrains, though, because the vehicles usually can deal with the length added by the housing motor setup. Having power routed through a transmission, transfer case, prop shafts, and f/r diffs is a good thing for something like a Tundra.

The issue with the parallel systems are ultimately design decisions. Toyota gives the vehicles just enough power and nothing more. The Rav4 hybrid feels pretty darn nice. But then they throw a really similar drivetrain into something like the Highlander or Sienna where it feels strained. The UX would feel great with the A25A hybrid... but they chose to put the M20A hybrid in it. Corolla could have the 180hp M20A hybrid... but instead gets the 125hp 2ZR hybrid. I would say that Camry and Rav should be the benchmarks on how to do a hybrid.

Its all kind of moot anyway. The Rav4 Prime and NX 450h+ prove that the engine attached to the system will matter little in the near future.
 

ssun30

Expert
Messages
2,236
Reactions
5,224
I'm probably going to get shot for saying this but I never really liked the PS hybrid, no doubt they get great fuel economy especially in stop and go traffic, but the performance and driving feel leaves much to be desired IMO, they just don't quite have that direct and punchcy feel when you step on the throttle. Honestly kinda want Toyota to implement P2 hybrid into their regular cars. Btw would P2 hybrid actually be cheaper than PS hybrid since it's much simpler than PS?

I find it very interesting a TMEC senior engineer has always been very critical of THS and thinks it's a mistake, even though he played a crucial role in developing one of the best hybrid systems in the world (A25-FXS '300h'). His opinion is Toyota should have switched to a mix of serial (for economy) and P2 parallel (for performance/utility) earlier. He thinks the only reason THS is so good is 2 decades of experience but not fundamental superiority. He admits because of the mechanical simplicity (much fewer moving parts than P2), THS hybrids are almost as reliable as their ICEVs, but also argues that's one more reason to go for serial hybrid which further simplifies the mechanical parts.

My understanding is PS was a compromise made when electric motors and batteries are big and heavy and mechanical transmissions are very inefficient (think about 90s AT, you can even feel the transmission fluid sucking away all the power). It was never the best solution for every situation but overtime became very versatile and scalable that it could fit in most products they sell. As for cost PS HEV is already similar to ICEV but P2 is always more expensive than an ICEV.

Toyota decided P2 for passenger cars was not worth it after they tested it on the Estima and Crown hybrid in mid 2000s. The P2 system for Tundra was originally developed for Hino medium-duty trucks and is a proven design with 10 years of commercial service. Then there is THS-R for their Le Mans cars, they've talked about adapting it to road cars since 2017 but we still haven't seen it happen.

As for driving feel it's entirely a matter of calibration. PS can be made very punchy and responsive as in the example of last-gen ChDM Corolla Hybrid. It was faster in 0-50km/h than BMW 320i but they scaled back power response in the current-gen after customers complained last-gen was too sensitive and jerky. S220 Crown hybrid with multi-stage can go from EV mode to max power in 300ms so that's definitely not an inherent problem with PS.
 

Levi

Expert
Messages
1,603
Reactions
1,921
Too sensitive and jerky? Is that why certain Toyota models keep getting slower and less responsive with every new generation because most of their loudest customers are a bunch of wimps?
yes. it has unfortunately been like that. the customers that want reliability and performance are a very tiny niche, because performance customers in general have another requirement, which is badge status. toyota does have some pet projects as we say, but they just have to compromise between performance and price (think GT86 and LFA, all that is between).
 

ssun30

Expert
Messages
2,236
Reactions
5,224
Too sensitive and jerky? Is that why certain Toyota models keep getting slower and less responsive with every new generation because most of their loudest customers are a bunch of wimps?
Because cars are also meant to carry more than one person. For passengers a jerky car is a very unpleasant experience. That's actually a reason a lot of people who rode in my BYD Qin decided to never buy an EV.

Toyota actually took that feedback in C-HR EV too. They artificially added a 300ms ramp-up period in throttle mapping to simulate the typical response time of a naturally aspirated ICEV.

We are so used to automobile only carrying one person that we forget passengers experience very differently to drivers.
 

ssun30

Expert
Messages
2,236
Reactions
5,224
Geely launched its Leishen Power lineup of hybrid systems claiming world's highest efficiency hybrid ICE and world's most compact two-motor hybrid transaxle:

The Leishen Power series consists of two ICE and two hybrid transaxles:
>> DHE15 is a 1.5L I3, turbocharged, Miller cycle ICE with low pressure EGR. Output is 110kW(150PS) and 225N.m(166lb.ft) and max thermal efficiency is 43.3%. Its direct comparison is M20A-FXS with 112kW/190N.m/41%.
>> DHE20 is basically scaled up version with one more cylinder. Output is unknown but rumored to be 161kW(220PS) and 320N.m(236lb.ft) with similar thermal efficiency.
>> DHT is a single-stage dual-motor serial-parallel hybrid transaxle with similar operating mechanism as Honda i-MMD. Like THS-II all hybrid components are in one package.
>> DHT Pro adds a three-stage planetary gearset (similar to Toyota's multi-stage concept) to allow much higher torque capacity and high speed efficiency. At 120kg it could output 4920N.m of torque to the drive axis.
>> Like THS it's highly modular allowing for full-hybrid, range-extended EV and plug-in hybrid layout. The architecture could be scaled up to 475kW(650PS) in eAWD PHEV form. THS-II in its current form is scalable to just half that amount.
>> Claimed fuel economy of DHE15+DHT Pro is 3.6L/100km (65MPG-US) for a mid-size crossover. That's 23% lower than RAV4 Hybrid although the cycle is unspecified.

LS4.png
LS1.jPEG

There are other similarly impressive hybrid systems launched early this year. One common theme is 40+% efficiency ICE and integrated hybrid transaxle with Honda-style serial-parallel architecture. It is worth noting all these ICEs cannot operate without a hybrid system. So the high efficiency is probably from a very high degree of electrification. I would say they are still behind in ICE technology although that gap has reduced to 5-6 years (Toyota originally developed a 42% ICE for 2015 Prius but decided to kill it since it was not worth the cost and stayed with an ESTEC evolution of 2ZR-FXE instead).

While Toyota still has a huge lead in hybrid control software and NVH, the weaknesses of PS-style THS (power and full speed-range efficiency) are becoming increasingly vulnerable. Because new regulations heavily favor HEVs, Toyota/Honda could no longer take their duopoly for granted. Let's hope TMC doesn't rest on its laurels. Seriously, when the very engineers who developed THS-II get frustrated with the lack of power and efficiency, they need something truly innovating with the 2025 powertrain overhaul (THS-III?) instead of an evolution of current THS-II.
 
Last edited:

carguy420

Follower
Messages
293
Reactions
357
Personally I really question the true performance and efficiency of Geely's regular non-hybrid powetrains based on the real world driving done by my country's car journalists and owners of the rebadged cars that came to fruition from the Proton-Geely partnership, so I'm quite sceptical about their hybrid systems.

I really hope TMC has something ready to replace THS-II that will be a big step forward in power and efficiency, but what are the right improvements and changes they should make though?
 

spwolf

Expert
Messages
3,124
Reactions
3,217
Specs are cool, real life is why Toyota is so far ahead.

Only reason their sales are so up in Europe is superiority of their hybrid system.

It is also way more realiable than their own ice powertrains.

So they will definitly not change to P2 system, they would be losing all the benefits that matter to them and their customers.

Germans basically have up on full hybrids and are moving to plugins since they can't catch up so they are skipping one step.

Toyota will on other hand produce 2m full hybrids this year, and it would have been 2.5m if not for shortages.
 

Levi

Expert
Messages
1,603
Reactions
1,921
Germans basically have up on full hybrids and are moving to plugins since they can't catch up so they are skipping one step.
The thing is that TMC's hybrids are so good, that for them to make PHEVs is "child's play". Out of nowhere, the RAV4 is now the best plug-in available, with all the qualities of the best possible hybrid, best e-range, and now even good performance and best performance in the Toyota range after Supra. Is the RAV4 PHEV expensive? Yes, but so are other ones, yet in the long run it might be the cheapest thanks to its reliability.
 

spwolf

Expert
Messages
3,124
Reactions
3,217
Yes, two things though - without full battery, hsd has 20% lower consumption than germans.

But at the same time, they started adding more battery so hopefully tmc updates rav4 to add 20-30% more battery