The Mitsubishi MIVECs are the most frequently overlooked performance
engines. Everyone knows about VTEC, VVT-i and all of the turbocharged engines
floating around - but what about the ol’ MIVEC?
We check out the range of MIVEC engines available from Japan and on the local Australian
market...
|
What is MIVEC?
In the early ‘90s, Mitsubishi Japan introduced a valve control system to
combat Honda’s VTEC design. This system is labelled MIVEC (Mitsubishi Innovative
Valve and Lift Electronic Control System).
In its simplest form, MIVEC switches between two different intake and exhaust
cam lobes depending on engine rpm. At low rpm, the valves receive relatively
modest lift and opening duration. At high rpm, the secondary cam lobe is engaged
and the valves receive greater lift and duration (which results in increased
overlap).
The purpose of the secondary cam lobe is to deliver greater engine breathing
and the ability to maintain torque at very high rpm (which means greater power).
The MIVEC system achieves its high power without the driveabililty, fuel
consumption and emissions trade-offs typical in a conventional engine.
In addition to the base MIVEC principle, Mitsubishi also released a
sophisticated MIVEC-MD (Modular Displacement) system in the
‘90s.
The MD system is an early form of cylinder deactivation which involves
closing the intake and exhaust valves at light engine load. This means the
driver must open the throttle further to maintain power and, as a result,
pumping losses are reduced and active cylinder pressures are increased. This results in
greater efficiency and fuel economy.
Depending on conditions, the MIVEC-MD system can reduce fuel consumption by
10 – 20 percent.
|
The 1990s...
The first production car to appear with MIVEC technology was the
Japanese-market Mitsubishi Mirage Cyborg of late 1992. The Cyborg packs a
magnificent little 1.6-litre transverse four boasting DOHC, 16 valves and, of
course, variable valve lift and duration. With a high 11:1 compression ratio
(making premium unleaded fuel mandatory), the 4G92 MIVEC 1.6 screams out 129kW
at 7500 rpm and 167Nm at 7000 rpm. To put things into context, that’s about 10kW
more than the famed Toyota 4A-GE 20 valve and Honda VTEC 1.6 engines!
A MIVEC MD (Modulated Displacement) version was also available. The MD engine
makes the same power but with superior fuel economy. Unfortunately, it appears
that the MD version was dropped in 1996.
With a close-ratio 5-speed manual or 4-speed auto driving the front wheels,
the Mirage Cyborg is one of the most responsive and fastest hatchbacks ever
built – it’s guaranteed to get you pumped up! The MIVEC Mirage was continued
until 1999.
For a full review check out Pre-Owned Performance - Mitsubishi Mirage Cyborg R.
Also sold in Japan from 1992 was the MIVEC-powered Lancer MR sedan. The
Lancer MR uses the same mechanical configuration as the Mirage Cyborg (which
means 129kW and 167Nm). A Modulated Displacement version was available to order
but was axed in 1996.
The final application of the 4G92 MIVEC engine was in the 1994 Mirage Asti RX
coupe. There were no mechanical changes to the engine. The Asti MIVEC range was
later expanded to include R and ZR models. The Modulated
Displacement engine was not offered. The MIVEC Mirage Asti lasted until 1999.
The second MIVEC engine joined the stable in late 1993.
The MIVEC 2-litre V6 (coded 6A12) debuted in a Japanese-market medium size
sedan known as the Mitsubishi Eterna Visage R. The small capacity V6 isn’t as
highly tuned as the MIVEC 4G92 four but in manual form it easily cranks out
147kW - about the same as a contemporary 2-litre turbo engine. Peak power
arrives at 7500 rpm while peak torque (200Nm) is found at 6000 rpm. In
comparison to the 4G92 MIVEC, this engine runs a relatively modest 10:1
compression ratio, but it still requires premium unleaded fuel.
The Eterna Visage R comes with either a 5-speed manual or 4-speed auto.
Interestingly, the auto version is detuned to 143kW but generates 2Nm more
torque (202Nm) at the same revs. The Visage R was also available in Modulated
Displacement guise from late 1994. The line was discontinued in 1995.
The same 6A12 MIVEC V6 was also fitted in the slightly larger 1993 Galant
VX-R and 1994 Emeraude Super Touring R. Again, the 5-speed manual version makes
147kW/200Nm while the auto makes 143kW/202Nm. From late 1994, a MD version
replaced the normal MIVEC model - this gave these family-oriented sedans a
welcome fuel consumption reduction. The Galant and Emeraude Super Touring R were
axed in 1995.
The next application for the 6A12 MIVEC V6 was in the snout of the go-fast
FTO coupe.
The FTO was released in 1994 as the spiritual successor to the Galant FTO of
the early ‘70s. In top-line GPX trim, the FTO is powered by the 6A12 2-litre V6
with DOHC, 24 valves and MIVEC. Compression ratio remains at 10:1 and,
regardless of transmission, it generates 147kW at 7500 rpm and 200Nm at 6000
rpm. The engine comes tied to a 5-speed manual or INVECSII 4-speed auto with
sequential shift.
The MIVEC-powered FTO was later released in GP Version R spec and the line-up ended in 1999. See Mitsubishi FTO MIVEC V6 GP Automatic for our test of the FTO GP MIVEC.
The most powerful MIVEC engine arrived in early 1995 with the Japanese-market
Diamante 30M.
The Diamante 30M (recognised as the KE Verada in Australia) is equipped with
a 3-litre V6 packing DOHC MIVEC heads. With the same 10:1 compression ratio as
the little 2-litre V6, the big 3-litre MIVEC (coded 6G72) roars out 199kW at
7000 rpm and 301Nm at a relatively low 4500 rpm. Premium unleaded fuel is
required.
This monster comes tied to a 5-speed INVECSII sequential auto and drives the
front wheels. Unfortunately, the MIVEC 6G72 had a very short lifespan – it
lasted only until mid 1997 when the GDi engines took over.
The Current Decade...
In early 2004, the Mitsubishi Grandis people-mover became the first vehicle
sold in Australia with MIVEC. But be careful how you interpret the application
of the MIVEC name...
The MIVEC system in the Grandis is completely unlike the previous
high-performance systems that alter inlet and exhaust valve lift and duration.
In this incarnation, MIVEC means only variable inlet valve lift and duration.
With a basic SOHC, 16 valve head and a tame version of MIVEC, the Grandis
engine (coded 4G69) makes a conservative 121kW at 6000 rpm and 217Nm at 4000
rpm. The MIVEC system switches to its second stage at 3600 rpm. A 9.5:1
compression ratio means no problem using normal unleaded fuel and, indicative of
the engine’s modest performance, it’s sold only with a 4-speed automatic with
sequential shift.
See Mitsubishi Grandis for our Grandis test.
In late 2004, the Grandis was joined by the updated Outlander which uses the
same 4G69 engine. In Outlander guise, the engine makes 120kW at 5750 rpm and
220Nm at 4000 rpm. Ninety-five percent of peak torque is on tap at 2500 rpm. The
AWD Outlander is also available with only an auto transmission.
Late 2004 also saw the debut of the all-new Colt.
The Colt is powered by a 1.5-litre four with a DOHC, 16 valve head and MIVEC.
The engine (jointly designed with DaimlerChrysler and coded A9) also
incorporates electronic throttle control, tubular extractors and low-friction
pistons. It appears that, like the 2.4 litre MIVEC in the Grandis and Outlander,
this engine has a MIVEC system that operates only the intake valves. With its
10:1 compression ratio, the engine survives with normal unleaded fuel and
generates 72kW and 132Nm (at 6000 and 4250 rpm respectively). See Mitsubishi Colt LS Test
for our Colt road test.
At the time of writing, Mitsubishi announced the release of three more MIVEC
engines.
Interestingly, the new Outlander (which is due for release in Japan in
October 2005) will come powered by a 2.4-litre MIVEC engine that appears very
similar to that already sold in Australia. However, with 125kW, the new engine
is slightly more powerful than the current 4G69 2.4-litre MIVEC and is expected
to achieve a 4-star LEV rating.
The Mitsubishi new-concept minicar i (due for Japanese release in
early 2006) will be powered by a turbocharged 660cc three-cylinder MIVEC engine.
Class regulations limit engine power to 47kW and torque figures are yet to be
finalised. This little buzzer is expected to earn a 3-star LEV rating and return
around 15 percent better fuel economy than the current 3G83 turbo
three-pot.
Finally, the yet-to-be-released Lancer Evolution 9 will also incorporate
MIVEC variable inlet valve timing. Together with few other mechanical changes,
the mighty Evo has now cracked 400Nm of torque.
MIVEC mumbo lives on!
Did you enjoy this article?
Please consider supporting AutoSpeed with a small contribution. More Info...
|
More of our most popular articles.
|
|
|
Email a friend
Print article
|