MIVEC vs VTEC vs VVT-I

i think VVTi and Vtec are same

Duh! VTEC

VarioCam/VarioCam Plus which is used on some of the Porsche engines,
MIVEC(Mitsubishi Innovative Valve timing and lift Electronic Control) which is used on the Mitsubishi engines,
VVT-i(Variable Valve Timing with Intelligence) and now VVTL-i (Variable Valve Timing and Lift with Intelligence) which is being used on the current Toyota and some Lexus engines,
VVL(Variable Valve Lift) which is used on the Nissan engines and also featured in the 350Z is the CVTCS (Continuously Variable Valve Timing System)
VANOS(Variable Onckenwellen Steuerung) which is used in the BMW engines and also the Double VANOS system on the new 3 Series and they are many more similar systems used by manufacturers such as Ford, Lamborghini and even Ferrari.

Honda was the first to offer what it called VTEC in its Acura-badged performance models like the Integra GS-R and NSX (it has since worked its way into the Prelude and even the lowly Civic). VTEC stands for Variable Valve Timing and Lift Electronic Control. It basically uses two sets of camshaft profiles-one for low and mid-range rpm and one for high rpm operation. An electronic switch shifts between the two profiles at a specific rpm to increase peak horsepower and improve torque. As a VTEC driver, you can both hear and feel the change when the VTEC "kicks in" at higher rpm levels to improve performance. While this system does not offer continuously variable valve timing, it can make the most of high rpm operation while still providing solid drivability at lower rpm levels. Honda is already working on a three-step VTEC system that will further improve performance and efficiency across the engine rpm range.

The camshaft in a pushrod engine is often driven by gears or a short chain. Gear-drives are generally less prone to breakage than belt drives, which are often found in overhead cam engines.

Toyota saw the success Honda was having with VTEC (from both a functional and marketing standpoint) but decided to go a different route. Instead of the on/off system that VTEC employs, Toyota decided it wanted a continuously variable system that would maximize valve timing throughout the rpm range. Dubbed VVTi for Variable Valve Timing with intelligence (Is this a dig at Honda, suggesting their system isn't intelligent?), Toyota uses a hydraulic rather than mechanical system to alter the intake cam's phasing. The main difference from VTEC is that VVTi maintains the same cam profile and alters only when the valves open and close in relation to engine speed. Also, this system works only on the intake valve while VTEC has two settings for the intake and the exhaust valves, which makes for a more dramatic gain in peak power than VVTi can claim.

Ferrari has a really neat way of doing this. The camshafts on some Ferrari engines are cut with a three-dimensional profile that varies along the length of the cam lobe. At one end of the cam lobe is the least aggressive cam profile, and at the other end is the most aggressive. The shape of the cam smoothly blends these two profiles together. A mechanism can slide the whole camshaft laterally so that the valve engages different parts of the cam. The shaft still spins just like a regular camshaft, but by gradually sliding the camshaft laterally as the engine speed and load increase, the valve timing can be optimized.

VVT"L"-i is only used on the 1/2ZZ-GEs and works on both Intake and exhaust cams. All others Toyota motors are VVT-is.

gr8 info...
if considering the names of the technologies than mivec is the coolest...

@racer bhai
the technology in which petrol is directly injected into the cylinder... whats its name for mitsu...???

GDI. Gasoline Direct Injection!

any practical performance gains in gdi...
and the equvilant audi's technology is fsi????

Umm cleaner engines as lesser NOX and soot produced, more economical as less fuel wasted. Its very much like the FSI which stands for Fuel stratified injection. Its actually patented by VW not Audi!

thanks adeel bhai
btw
audi pays vw for using this????

Audi OWNS VW.