One of the difficulties in assessing cars – whether new, secondhand or modified – is that no matter how extensive the spec sheet, you can never tell how well the cars drive until you do just that… drive them.

As I write this I’m in Sydney, here for the week with Michael Knowling to collect lots of stories. A few days ago we were at MRT Performance, the Subaru specialist tuners and modifiers. The company uses the ECU-Tek software package to modify the factory ECU, an approach which works very well. In addition, they often fit upgrade turbos, exhausts and intake systems. Anyway, one of the cars on which we were doing a story was a current model XT Forester. Factory turbocharged, this particular one came with an auto trans.

Now I know what you’re thinking: an auto Forester turbo doesn’t sound the stuff of immense excitement, does it? Even when it has a new turbo, up-pipe, ECU upgrade, exhaust, intake and fuel pump. But forget the specs: this car was dynamite. The turbo was quick to spool, with the torque converter completely covering any bottom-end hole that might have existed. The combination of mid-range torque and the auto trans gave extraordinarily strong punch, and the ability to effortlessly leap from the line was the stuff that manual trans WRX owners can only dream of.

In short, with a 0-100 in the high fives and absolute flexibility and tractability, this was something far better than you’d have ever guessed from the bare specs. And of course, with the wagon body, leather trim and huge sunroof, the Forester is an eminently comfortable and practical car as well. One that in this case just happened to go like a bloody rocketship…

But MRT also had another Subaru for us to drive. This was only trivially modified – the current model Liberty 3.0R wagon ran just a small cat-back exhaust upgrade. With a flat six boasting in standard form180kW, the $52,990 luxury-trimmed Subaru immediately felt sophisticated and settled on the road. Typically good Subaru steering, an excellent ride – and comfort, luxury and performance.

Er, well, no. Not performance, anyway.

I doubt the exhaust made any difference – up or down – in power, although it did give the car an interesting note. But this new six is just as flat as a pancake! Despite the Active Valve Control System and Variable Valve Lift, despite the electronic throttle and six-speed manual trans, it simply felt gutless. Nothing down the bottom end of the rev range, little in the mid-range and not a helluva lot more at the top end!

Like, any manual-trans Magna would eat it for breakfast, let alone an old 180kW Ralliart.

I don’t know what the factory performance specs are – and it doesn’t much matter. This is a car that is seriously pedestrian in performance. Smooth, sure, but fast – not! It has the quoted power, it has the quoted relatively light weight (about 1500kg), it looks the goods, but it doesn’t go. A competent and pleasant family machine with (no doubt) good all-wheel drive handling. But no more than that.

In fact, it kinda reminds me of the new Holden Alloytec engine. (Not in NVH; the Subaru is much nicer!) But for something automotive no where near living up to its on-paper specs, the new Alloytec engine has to take first place. I haven’t yet driven the top-line 190kW version, although I have listened long and hard to Michael’s less-than-complimentary views on the SV6 that he had for a week on test (see Holden VZ SV6 Manual Test).  But the base 175kW engine tied to the old four-speed auto is, well, lousy.

Yes, despite the glorious on-paper, cutting-edge specs (best covered at Holden’s New World Class V6), this is an engine that feels old and tired.

I’ve read newsgroup responses to media criticisms of the engine as being noisy and harsh which have suggested that the engine is anything but that. “Mine is smooth and sweet,” say some of the indignant owners. Well, guys, go drive a V6 Camry or Avalon. Now that’s a sweet V6. Even the now quite old Magna V6 doesn’t sound like it’s about to burst a blood vessel when taken near to peak revs. I mean, the 17 year old supercharged 1G-GZE in-line six in my Toyota Crown is a far nicer engine…

It’s hard to find anything to recommend the Alloytec. Idle quality is poor (vastly poorer than the competitor Falcon six cylinder), the performance is nothing special, NVH we’ve touched on, and test fuel economy was average.

I think that over time Holden engineers will fix many of these aspects, but the fact remains that right now, the Alloytec is the engine that you experience if you want to know what bottom of the class feels like. It’s also salutary to consider that the old and bad tradition of never buying the first model of anything from Australian car manufacturers (think JB Camira, EA Falcon, early four cylinder Magna) continues with the Alloytec engine. (How Holden performs with the all-new next model Commodore will be doubly fascinating. They now have to fix the engine as well as come up with a car!)

Of course specifications are important… but they’re certainly not the whole story. To find that, you need to drive …