Road Test: VZ Holden Commodore SV6

By Feann Torr - 15/04/05

When Holden launched its rear-wheel drive large car, the VZ Commodore, in late 2004 it left behind an old friend who had been in service since the VN Commodore shipped in 1988 - the 3.8-litre Buick-sourced V6 engine.

Often labelled as a 'piece of junk', the 3.8-litre 2-valve pushrod engine may have been low tech, but in supercharged form it hammered, and it had character too. Just check out this review for evidence.

But now the old 3.8 bent six is gone, and after 17 years of service to GM Holden there's a newer, more advanced and more powerful engine to pick up the slack in the form of the 3.6-litre 'Alloytec' engine.

You can get you hands on the new V6 Alloytec engine by signing the cheque for $33,650 (plus on road costs) for the entry level Commodore Executive, which gets you the 175kW version of the engine.

The car on test, however, costs a little more - a smidgen under $40,000 - but for the extra bucks you get a mean-looking bodykit, a 6-speed manual transmission, sports ride and handling, big alloy wheels and most importantly, the Alloytec 190 power plant. This engine displaces the same 3.6-litres as the 175kW version, but is in a higher state of tune, outputting 15 extra kilowatts, taking the total to 190kW.

A worthy combatant for the venerable 182 kilowatt Ford Falcon XR6, this SV6 review was also our first chance to test out the new 3.6-litre engine, so with just two more words, let's roll.

Holden's VZ Commodore SV6 is the only model equipped with the Alloytec 190 and a 6-speed manual gearbox

Hunkering down into the generous Holden-issue semi-sports seats, the key in the ignition, I was rather surprised when nothing happened.

There's no FPV-style starter button, no bananas in the exhaust pipe - what gives?

Damned new age engines... You know you're driving something different when for the first time in almost two decades you have to press the clutch in to ignite the engine.

But after giving the engine a bit of a stir, all fond memories of the old 3.8-litre pushrod engine faded into the distance as the new V6 did its thing.

It's a smoother, more refined engine and is more willing to rev, thanks to lower reciprocating masses due to the reduced engine displacement.

Compared directly to Holden's V8 engines, the 3.6-litre bent six feels sluggish, but that's an unfair comparison.

On it's own merits the SV6 will accelerate away from the traffic lights at a good clip, and when you consider that prices have risen only marginally over the decidedly low-tech 3.8-litre models, it makes for a good value proposition.

With barely more than three and half litres of six carefully balanced cylinders propelling a 1600kg car, the engine performs well. It's not light years ahead of the old Buick engine, neither in terms of noise or pulling power (though harshness and vibration have been improved), but it certainly feels a lot more composed, more refined if you will, particularly at higher revs.

In the Alloytec 190, there's a certain willingness to rev that wasn't there with the old V6 motor, though don't expect to be chirping the wheels in the SV6 (unless the road is wet or you savagely drop the clutch at high revs).

Its power delivery is crisp and clean however, the electronic throttle making quick bursts of acceleration delightfully easy, and it's more than powerful enough to void your license quick-smart.

Speaking of license voiding activities, the gear ratios are well-spaced and make good use of the engine's wide spread of torque, and more than warrant the SV6's sporty badging. The new 6-speed manual transmission also has shorter shift throws that the outgoing 5-speed manual, and moves cleanly between the gates.

Not only is the SV6 a great tool for cornering, but it actually looks the part too. Nice work Holden!

The engine feels stronger in mid gear roll-ons (2nd, 3rd gears) from highway speeds - for instance around 70 or 80km/h - than from standing starts.

In the world of stop signs and traffic lights, the Holden Commodore SV6 is a bit sluggish off the line, to about 30km/h, even when Holden claims that the Alloytec 190 delivers 90% of its maximum torque from 1570rpm.

But as the revs build and the torque volumes increase, it really gets a move on, and the audio from the engine as it spins up to nearly 7000rpm is quite sonorous. It'd sound great with a less restrictive Mandrel-bent straight-through exhaust system, no doubt about that.

Fuel economy isn't that much better than the old 3.8-litre 'Ecotec' engine - about the same in fact - but where the SV6 shines brightest is through the corners.

Thanks to the much lighter all-alloy engine than the V8 equipped models, there's a lot less weight over the front end, and together with a tight chassis that begs to be spanked hard - and one that doesn't always have to play catch-up with the crisp turn-in - the car is much more confidence inspiring than it's bigger sibling (the SS Commodore) when it comes to attacking apexes at full tilt.

In fact, I don't think I've ever had quick this much fun in Holden - it just seemed to work well in the bends, and communicated differing grip levels with aplomb.

Go into a corner too hot and brakes do their thing admirably, go in too cold and you can effortlessly and smoothly wind out third gear through the corner as you feel the suspension load up. With low levels of body roll, no searching for gears and no automatic transmission hiccups, this car is a true weekend warrior.

There's not a lot of understeer in SV6, enhancing it's point-and-shoot quotient, where the the heavier V8s would sometimes push the outside front wheel in similar situations, and though the steering is typical Holden - a little heavy - there's adequate feedback from the 17-inch wheels for a car that's priced under 40-large.

I reckon the SV6's impressive cornering characteristics come down to a handful of components:

The aforementioned lighter front end that helps improve initial turn-in
Fixed-mount anti-roll bars front and rear
A fairly light (for a boofy Aussie car) 1592kg kerb weight
Independent MacPherson strut suspension up front
The VZ model's tweaked power steering
Grippy 235/45 R17 tyres on 17-inch alloy hoops

Any negative points about the way the car drives? Not really. It's an accomplished vehicle. Arguably one of Holden's best cornering tools, the SV6 fulfils its purpose as a family vehicle to boot, eating up the kilometres on the open road without too much impact to one's wallet, and offering a relatively smooth ride and responsive handling in mundane conditions.

Because it's equipped with the more rigid 'sports' suspension tune, it doesn't cosset occupants quite as deftly as in other not-so-sporty Commodores, but at the same token it's not like you'll feel every manhole and drain you drive over. Holden knows that its customers do like a smooth ride, and the balance struck between minimal body roll and smooth rebound and compression damping works effectively on Australia's somewhat hackneyed roads.

GM 3.6-litre Alloytec 190

The Alloytec 190 engine (top) and the continuously variable cam phaser (above) The 60° Vee 6-cylinder engine has a 3.6-litre (3565cc) capacity and takes advantage of programmed fuel injection to deliver the fuel to the cylinders. The engine block and cylinder heads are both constructed from lightweight aluminium alloy, and 4-valves per cylinder (24-valves in total) are actuated by dual overhead camshafts (DOHC) per cylinder bank. The camshafts are chain driven and feature variable valve timing (VVT) on the intake and exhaust valves, where the Alloytec 175 only has VVT on the intake cycle. Max Power: 190kW @ 6500rpm Max Torque: 340Nm @ 3200rpm Another feature the Alloytec 190 has over the less powerful 3.6-litre 175kW engine is the dual stage variable intake manifold (VIM). The VIM incorporates an electrically operated valve within the manifold that in ordinary operational modes partitions the plenum into two openings. When engine speeds surpass 4000rpm, the VIM valve opens and all cylinders feed from a single plenum. The effect of this is that it boosts ram cylinder charging volumetric efficiency at high speeds. In layman's terms: the engine gets more air and more power at higher revs. Holden's Alloytec 190 engine also gets pressure-actuated piston oil-jets that to help cool the underside of the pistons to achieve higher power and durability. Furthermore, this additional oil supply not only cools the pistons at higher revs, but reduces noise from piston contact with the cylinder bore as well. A high compression ratio of 10.2:1 ensures high output, yet the SV6 can still be filled with bog standard 91 RON unleaded petrol, though you will get better performance with higher octane fuel/octane boosters. Finally a big 75-litre fuel tank in tandem with a combined city/highway fuel consumption figure 11.6 litres per 100km equates to a tank distance of slightly more than 640 kilometres, though we clocked closer to 400km from a tank due to hard driving.

The SV6 has an appealing exterior, one that takes the basic VZ Commodore shape - which is already easy on the eye - and improves it with a small amount of muscle, and by giving it a ground-hugging profile.

A low-rise rear spoiler with LED brake light integration, an aero bodykit consisting of side skirts, front and rear aprons plus front fog lights, and a set of simple-yet-sporty 17-inch alloy wheels give the car a measured amount of sportiness, without going completely over the top.

The sports steering wheel feels great, with ergonomic contouring, and the sporty dials help convey a sense a high performance

You may also note the return of the oval exhaust pipe from V8-equipped VT and VX model SS Commodores, which is nicely integrated into the rear apron.

The interior? Just as impressive as the way the car handles. Though I still think Holden could improve the quality of the dash plastics and what not, in order to match the Ford Falcon, the SV6 represents good value for money nevertheless.

There's bags of room for five passengers, a voluminous 465-litre boot, child seat anchorage points and very comfy seats (with lumbar adjust) that won't cane your back on longer journeys.

The sports trim consists of colour matched seats upholstered in cloth (leather is a $2050 option) and a somewhat sporty instrument cluster with twin circular tacho and speedo dials, while a 4-spoke leather-wrapped steering wheel ensures pleasant tactility for the driver, while also offering remote stereo controls.

Things like air conditioning and cruise control come as standard on the SV6, as do electric windows and mirrors, not to mention a CD stereo that blasts through a 6-speaker, 80-watt system.

Safety wise, the Commodore SV6 is one of the most competent Australian cars on the market in this price range. In addition to ABS, traction control (TC), electronic brakeforce distribution (EBD) and brake assist (BA), the $39,690 SV6 benefits from dual front airbags as well as side impact airbags.

Overall: 4/5

With the old 3.8-litre mill disposed of, the Alloytec begins a new legacy for the Holden Commodore. And from our first impressions, it works well, but isn't perhaps the massive jump in performance we were expecting.

As for the car as a whole, it's great. I had a lot of fun driving it enthusiastically, but even in less demanding situations it fulfils its job as an A to B commuter just as diligently, and with heaps of interior room it's incredibly practical. Indeed, after driving hundreds of Ford and Holden large cars, one often forgets just how roomy and downright useful they are.

Compared to the naturally aspirated XR6, the shiny new SV6 is a much more competent rival than the old Commodore S, and will return better fuel economy to boot.

More than $10,000 cheaper than the SS and with more agility on the road, the SV6 makes a lot of sense to my mind. Though it may only be $4000 cheaper than the SV8, it still gets my vote as Holden's best value performance car, not singularly because of its impressive handling abilities, but also in relation to the current economic climate that is seeing - and will see - continuously rising petrol prices.