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Lexus CT 200h
Lexus adds another entry-level hybrid to its portfolio

Toyota is continuing its quest to spread hybrid technology throughout its entire lineup of vehicles and the next stop for the hybrid train is the all-new Lexus CT 200h. The CT 200h is the production version of the Lexus LF-Ch concept which debuted last year. Although the CT 200h is toned down quite a bit from its concept form, it still shares much of the design philosophy first seen five months ago.

Unlike its HS 250h sibling, the CT 200h forgoes the largish 2.4-liter inline-4 engine and instead uses a 1.8-liter VVT-i four-cylinder engine. As is the case with Toyota's other hybrid vehicles, the gasoline engine is paired with a continuously variable transmission (CVT), electric motor, and a NiMH battery pack.

Toyota isn't discussing official fuel economy numbers for the CT 200h, but it does say that the vehicle can travel a measly 1.2 miles and at up to 28 mph on battery power alone.

Assuming that the 1.8-liter VVT-i engine used the CT 200h is the same 2ZR-FXE motor used in the Prius, expect to see stellar fuel economy for the vehicle. The Prius is pegged at 50 mpg combined, but every aspect of the vehicle from its tires to its body shape to its underbody is designed to slice through the wind with the utmost efficiency. The CT 200h has a more conventional shape, but we'd be surprised if it dips below 40 mpg combined using the same powertrain as the Prius.

The Lexus CT 200h is due to debut for the European market later this year. It is unknown if the vehicle will find its way to the U.S. -- there may not be enough room in the Lexus lineup with the HS 250h already occupying the bottom rung.



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By Redback on 2/26/2010 11:43:17 AM , Rating: 2
quote:
You are clearly misinformed, I've never seen so many wrongs at one post before.

A word of advice. Perhaps before "correcting" others in such a snide and condescending manner, you should actually do some reading and know what you're talking about rather than just repeating drivel from the Prius fanboy club magazine.

Point by point:

1. So are you trying to say that a Prius has no transmission for its ICE? Bollocks. We both know it uses a CVT and integrating the additional drive of the electric motor requires a supplementary gearset. A series Hybrid doesn't require a CVT and doesn't need supplementary gears (with the exception of a primary reduction gear). Hell, if it's designed correctly, it doesn't even need a mechanical differential. (See link to Lotus 414E.)

2. Please point me to the external plug-in port on the current model Prius. Can't? You've proved my point then. Yes, I'm aware that parallel hybrids can also be plug-ins, but Toyota's aren't are they? And while battery technology selection has an impact on recharging options, the only reason plug-in ability is not included in the current Prius is cost and lack of foresight.

3. What would be the benefit of "pairing a small gas engine with a big electric motor" if they are both directly driving the wheels? Once again, you'd have transmission duplication, reduced mechanical efficiency and additional weight, all for the addition of a piddling amount of torque (produced by a small, relatively inefficient ICE).

4.Wrong! (You're not here for the hunting, are you?) An engine designed to drive the wheels of a car has to operate over a relatively wide speed range and its torque generating efficiency varies significantly with engine revs. It also requires a gearbox and even the best CVT suffers substantial mechanical losses between the engine and the wheels.
A purpose-designed engine/gen unit (such as the Lotus "Range Extender") operates within a very narrow rev-range for which it has been highly optimised, thus making it more fuel efficient. Electric motors are vastly more efficient than any ICE and produce so much torque across such a wide rev-range, they don't need conventional multi-speed or CVT transmissions (with their inherent mechanical inefficiency). In fact, the combined efficiency of the purpose-designed engine, generator and electric motors is significantly better than can be achieved with virtually any purely mechanical configuration.

And perhaps in your alternative universe, "the gas engine can directly drive the wheels", but on this planet there's usually a clutch, gearbox and differential involved, - all of which produce mechanical losses.

As I said in the opening paragraph, I suggest you do some reading...


By corduroygt on 2/26/2010 12:20:20 PM , Rating: 3
You should clearly take your own advice and do some reading, because you are wrong on all counts.

1. The Prius (and Fusion) does NOT use a CVT transmission. It's called e-CVT for marketing reasons but in real life it has nothing to do with a conventional CVT transmission. The Prius Power split device is a planetary gearset, it is 1-speed. No gear changes or clutches.

2. Please point me to an electric car that can go a reasonable range and power that doesn't cost $100K like the Tesla? How about where is the Volt? Prius plug-in is being developed and it'll be a 2011 or 2012 model, this is fact. When you try to make millions of real cars people use instead of expensive limited production toys for the rich, development and testing take some time.

3. Since you are absolutely clueless about the power split device "transmission", it's normal for you to ask this question. And it's not just a Prius thing, since the Ford Fusion uses it as well and guess what, it's also the best hybrid in its segment. The fact is you only need a small, efficient gas engine for cruising but you end up with a far larger one because of situations where more power is needed. In the Prius and fusion, what actually drives the wheels is an electric motor, while the gas engine can also optionally provide torque. That's why they can cruise with the gas engine fully off.

4. The Prius (and Fusion) atkinson cycle engine also operates within a tight envelope of throttle opening, load, and rev range, fine tuned by engineers over 10 years. It's remarkably efficient. Since there is no CVT or gears, the rest of your post becomes moot. The only thing preventing the prius from having a weaker gas engine and a more powerful electric motor is the cost of extra batteries required.

You are also flat-out wrong because mechanical transmissions, even with gears and cluthes, beat motor/generator combo in power transmission. The PSD still maintains this advantage while adding regen capabilities, so it truly is the best of both worlds.

Please be more informed in the future so you won't be embarassed again, and follow your own advice and do some reading.


By Keeir on 2/26/2010 2:38:45 PM , Rating: 2
quote:
You are also flat-out wrong because mechanical transmissions, even with gears and cluthes, beat motor/generator combo in power transmission. The PSD still maintains this advantage while adding regen capabilities, so it truly is the best of both worlds.


Urm.... thats not really sound thinking.

Lets look at the Toyota Prius itself in Japan, it barely gets 4 miles (Japanese Cycle) per kWh.

Japanese Cycle is ~ 40-45% more optomistic than the US EPA.

Plug-in Prius manages to get 2.8 miles per kWh! The Telsa Roadster gets ~3.5 miles per kWh.

If we make the assumption that #1. The Prius and Roadster take roughly the same power to move forward and #2. Prius efficieny system for Battery --> PSD is the same as Roadsters Battery --> Forward Momentum, overall the PSD --> Wheels is a reduction of 25%! (Btw, this same reduction would likely apply to regen capacities as well.

There seems to be the potential that a good generation ICE + electronics can get close to beating the Prius Aktinson + PSD.


By corduroygt on 2/26/2010 2:55:46 PM , Rating: 2
1. Tesla weighs 300lb less than a Prius empty, the difference will be even more when you add the fluids in the Prius. This will reduce fuel economy.
2. Tesla has advanced electronics to regulate battery charge levels and current, it may indeed be more efficient in discharging the battery than the Prius.
3. A single stage planetary gearset like in the prius is said to only lose 3% according to wikipedia:
http://en.wikipedia.org/wiki/Epicyclic_gearing

An electric/generator transmission is a lot worse than 3%, so I still don't see how the extra 3% efficiency in the city is going to make up for the massive deficiency in range extending mode on the highway.


By Keeir on 2/26/2010 3:57:47 PM , Rating: 2
1. But the Prius has a significant aerodynamic advantage AND Tire advantage.

2. Its entirely possible. But the Tesla is also designed to go from 0-60 in under 4 seconds. Traditionally this does not result in peak efficieny at normal driving.

3. So you really believe the PSD introduces only 3% losses into the system?!?

And somehow, the Plug-in Prius, acchieving less than 3 miles per kWh is because it wieghs so much?

The Mini E claims greater than 4 miles per kWh... and its essentially thrown together, wieghs more, and has a worse aerodynamic shape. I think the Mini-E doesn't include charging losses... which reduce the overall efficieny down to ~3.5 again, but this is still much much better than Toyota is claiming for the Plug-in Prius.

::shrug:: You have a good theory about the terrible results the Plug-in Prius acchieves on EV mode? The main difference is the PSD right?


By corduroygt on 2/26/2010 5:45:53 PM , Rating: 2
Aerodynamics don't matter much in the city, which is what I'm assuming from this "Japanese cycle" you're stating, because not even the plug-in prius can operate at highway speeds without the gas engine being on. I'd like to see the link to your numbers, and the tests, stating that prius was run in EV mode only with zero IC assistance.

Saying 25% difference due to PSD is preposterous. A manual transmission + differentials + tire/wheel inertia losses all adds up to 12-15% on the dyno, and that's a manual with a clutch and everything. PSD is much simpler andd all cars have diffs and wheels.


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