AN all-new DOHC V6 may be the headline act of its facelifted VZ Commodore launch, but Holden didn't overlook its flagship sports sedan when it came time to freshen up the Commodore SS. To avoid the potential of its four-door performance king becoming the meat in an SV6-Monaro sandwich, Holden has come with a couple of refreshingly novel and beneficial approaches to differentiating VZ SS from the smart new SV6 and the upcoming, more powerful VZ Monaro. Along with sharper new frontal styling and a now customary power and torque increase (up five points each to 250kW/470Nm), the latest SS offers a livlier driving experience via an electronic throttle, lower manual gearing, a more refined auto and steering tweaks. Oh, and exclusive new front quarter "speed vents".

VZ SS proves you don’t need radical peak power boosts, extra interior gadgets or the likes of adjustable suspension to make a smarter, faster and more driveable sports sedan.

And the fact electronic wizardry is largely responsible for creating the most responsive, refined and quickest SS ever is a credit to the basic but well sorted package that Holden has delivered with its premium sports sedan for about five years now.

The latest round of changes, albeit minor, has improved Commodore SS even further, but they had to: with a clever and quick new SV6 sports variant that’s sure to please believers of six-cylinder performance and a forthcoming VZ Monaro that will boast even more power, SS Commodore’s supremacy has never been more under threat.

Throw in a 260kW DOHC XR8, and the pushrodded V8 SS could well have been in danger of becoming a dinosaur.

But fear not, SS lovers and Holden marketing types, because while the extra power and torque keeps Holden’s premier four-door ahead of Holden’s all-singing, all-dancing new V6 and puts it virtually lineball with XR8 in terms of engine performance, the real deal here is the extra pace, response and flexibility wrought by shorter manual gearing and the addition of an electronic throttle.

Both auto and manual SS variants feel sharper in their throttle response, reacting more to any given accelerator pedal input than before and feeling smoother across the entire rev range, contributing perhaps even more to the feeling the Gen III is less muffled and freer-spinning than the peak power and torque hikes.

And the shorter final drive gearing allows the manual SS to launch quicker and feel even more pure than before, and closer to what a V8 sports sedan should be. Simply, SS manual now revs harder, easier.

On a racetrack or, say, in the Northern Territory, SS manual is now also more likely to revs closer to its redline in sixth, too. But in the real world, with only an extra 200rpm showing on the tacho at 100km/h in top gear, any fuel economy increase is negligible and well worth the extra highway overtaking tractability in top gear.

Makes you wonder why Holden persisted for so long with its moonshot manual gearing, which gave the original Chev-powered SS a theoretical top speed of more than 360km/h.

The auto doesn’t go neglected either, with a new torque converter and controller making substantial headway in reducing shift shock and hunting – the two greatest blights the SS auto has long suffered.

Like base model Commodore V6s that continue with the aged GM four-speed slusher, the SS auto is a big beneficiary of improved electronics, but the fact is both the Tremec six-speed and GM four-speed feel prehistoric next to the SV6’s Aisin six-speed manual and GM five-speed auto transmissions.

And the lack of stability control and its associated ABS upgrade – the virtues of which were heralded long and loud at the VZ launch – is a disappointment for the more expensive, more powerful V8 variant.

Despite the heavier, vaguer-shifting manual and its firmer clutch action (with reverse on the wrong side), purists will love the upgraded SS’s extra on-road performance, which brings it closer in refinement to XR and probably moves it further ahead in terms of acceleration.

As quick as an HSV ClubSport was just two years ago, VZ SS should still be a good second faster than SV6 to 100km/h (likely to complete the dash in well under six seconds) and about 1.5 seconds quicker over 400 metres (with times of under 14 seconds conservatively forecast).

While front rollbar changes have certainly added a little extra response - especially around centre – to give all Commodores better straightline feel, SS is not alone in feeling a little more pushy up front than before.

Holden admits to lowering the cornering forces at which understeer sets in, and the earlier onset of front-end push makes itself felt both when apexing late or powering out of corners early.

So while extra understeer at the limit won’t please the most enthusiastic of enthusiasts, most average drivers will benefit from sharper initial steering response at lower speeds, which makes Commodore’s tiller feel more alive and closer to that of Falcon, which probably now only wins on feedback.

The abolishment of the previous model’s awful throttle pedal push-back when traction control is activated is a clear improvement, however, and keen drivers will also appreciate its higher intervention threshold.

That pretty well sums up the VZ SS driving experience, though expensive sheetmetal changes were behind the addition of go-fast fender vents which really look the part. Clearly differentiating SS from any SV6 imposters, the vents are actually useless and some of the pre-production models we drove were poorly aligned, wobbled and the clear indicator lenses full of condensation.

But if that can be sorted on the production line, the fender vents will combine with a more aggressive new front-end and new 18-inch alloys to make VZ SS a winner in the looks department too.