Toyota Launches Redesigned Minivans in Japan; First Application of the New Valvematic System
02 July 2007
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| The Voxy ZS. |
Toyota has launched the completely redesigned Voxy and Noah minivans in Japan. The second-generation models mark the first applications of a newly developed 2.0-liter engine (3ZR-FAE) using the Valvematic variable valve lift mechanism with Dual VVT-i (Dual Variable Valve Timing-intelligent) which optimizes both intake and exhaust valve timing.
Valvematic improves fuel efficiency by 5% to 10% (depending on driving conditions), reduces CO2 emissions, boosts output by at least 10% and enhances acceleration responsiveness in the new 2.0-liter engine, according to Toyota. (Earlier post.)
The 3ZR-FAE Valvematic engine produces 116 kW (156 hp) of power and 196 Nm (145 lb-ft) of torque, with 10-15 cycle fuel economy of 14.2 kilometers/liter (7.0 l/100km or 33.4 mpg US). CO2 emissions are 164 g/km.
A non-Valvematic 2.0-liter engine also offered on the new minivans produces 105 kW (140 hp) of power and 194 Nm (143 lb-ft) of torque, with fuel economy of 13.4 km/liter (7.5 l/100km and 31.5 mpg US).
All vehicle models are equipped with the Super CVT-i (Super Continuously Variable Transmission-intelligent), and models with the 2.0-liter engine with Valvematic feature a seven-speed Sports Sequential Shiftmatic transmission with a paddle shift-type shift lever for the feel of a manual transmission.
Electric power steering smoothly varies the amount of steering assistance to provide optimum steering control according to vehicle speed.
An Eco Driving Indicator lights up when the vehicle is being efficiently operated to raise the driver’s awareness of “environmentally considerate” driving and contribute to higher fuel efficiency.
Toyota is targeting monthly sales of 5,000 units for each model in Japan.
Now if they have overcome the mechanical limitations of BMW's valvetronic and can use "valvematic" on a high revving engine, we may be getting a preview of what they are planning to use on the new Supra 500+hp V-10.
Posted by: Patrick | 02 July 2007 at 12:41 PM
Patrick:
Did you mean the new 600+ HP V-12 Supra?
Posted by: | 02 July 2007 at 02:59 PM
Source?
That would be interesting to have one engine for the Lexus LF-A and a different engine for the Supra.
Posted by: Patrick | 02 July 2007 at 04:34 PM
In discussions of the Valvematic it has been suggested that the there is no throttle butterfly. So the Valvematic engine is a cross between a Diesel and an ordinary gasoline spark fired ICE.
Has this now been confirmed ??
Posted by: Stan Peterson | 02 July 2007 at 06:07 PM
I don't think so. They simply have enough control of the cam that a throttle butterfly is superfluous. Based on my admittedly cursory understanding, the valve can be controlled such that the required amount of air is always allowed in, but they're still running at stoich.
Posted by: yesplease | 02 July 2007 at 10:02 PM
@Patrick -
The main point of variable valve lift is to save fuel at low power. People driving around in a 600hp Supra do not usually care one iota about fuel economy.
@Stan Peterson -
yesplease hit the nail on the head. Low valve lift performs the function of throttling at low power levels. It's more efficient than a butterfly valve for a number of reasons, but this SI engine still runs stoichiometrically (lambda = 1). Emissions are still controlled with a standard three-way catalytic converter.
Afaik, Valvematic is a purely mechanical system, just as BMW's is. Electromagnetic and electrohydraulic valve actuation systems do exist, but the great expense limits them to research engines.
Diesels and - to a lesser extent - stratified GDI engines run globally lean (lambda > 1), so there is plenty of oxygen left in the engine-out exhaust gas. This turns a three-way converter into a simply oxicat, so much more expensive strategies are needed to clean up the NOx (store cat, SCR or Honda's new system).
Posted by: Rafael Seidl | 03 July 2007 at 02:25 AM
Raf, raf, raf...must we re-hash this topic again?
With static valve lift (like you typically have on your average commuter car) you have to compromise most aspects of performance to get reasonable emissions, power, torque, and fuel economy.
With variable valve lift you can have an engine that meets all emissions standards with good fuel economy and high performance all at the same time.
Valve lift (and duration) has a strong correlation to the amount of power you can develop...just as it does the amount of fuel you consume and the emissions you spew out.
2-stage valve lift systems were not designed with fuel economy in mind, they were developed to get high performance out of small engines while still maintaining driveability. Better fuel economy has been exploited from this technology as an after thought...ever notice how the "high hp" Vtec engines came out before the "fuel sipping" Vtec engines from Honda? Mitsubishi's MIVEC (in the original early 90's form) was oriented to power...3 years after its introduction a fuel sipping "MIVEC-MD" came out. Toyota's 20valve 4AGE was never about saving fuel...just more power from a small displacement engine and they never tuned their variable valve timing or variable valve lift on the Celica GT-S for fuel economy, just power.
How do you produce more hp? Get a bigger engine or make a smaller engine rev higher...how do you facilitate engine breathing at high rpm? Increasing valve lift and/or duration [within limits].
Posted by: Patrick | 03 July 2007 at 09:12 AM