Without wanting to effectively bolt a turbo onto the already highly fuelled Forza vs Gran Turismo debate, it's become impossible to review the latest iteration of one series without acknowledging the other.
That's because the two games are racing along increasingly parallel paths: they share a vast appetite for an impressive - and in many instances, identical - vehicular menu; they recreate the same tracks with the precision of a Swiss watch, their individual approach as clinical as The Priory; and this time around they're even fighting over Top Gear's attention.
To make matters worse, in terms of handling models the boundaries have become as blurry as a Zonda's tachometer needle - comparing Forza 4 and GT5's dynamics is a bit like choosing between Ferrari and Porsche. Or, if you demand an even more indistinct comparison, Ford and Peugeot.
Still, to put a lid on things (at least until GT6 turns up), when it comes to the best overall game experience the latest Forza takes the chequered flag. There, settled. Now let's move on.
Forza 4, then, is everything you loved about Forza 3, and a little bit more. It is also, however, more than a little familiar if you're the single-player favouring type. You will wonder, as you embark on the World Tour career option and are bounced around a digitised map from a trio of race meetings to the next over the course of ten long seasons while building up your cash, driver level and manufacturer affinity levels, if you're suffering from a high octane form of déjà vu.
Clearly you'll spot the markedly improved visuals - some of the finest for a 360 driving game - with additional trackside elements popping up and a more organic level of detail in the scenery which cleverly contrasts with the seven to 11 expertly detailed cars around you. If you're playing in-car, then the wider camera angle will showcase more of the beauty around you - from dashboard to daffodils - in a manner that doesn't compromise the sense of immersion.
You're also bound to notice that your prowess on-track - cornering, overtaking, drifting, slipstreaming, tailgating, speed, and so on - gets rewarded by 'badges' (which you attach to your profile, should you wish to). And when you level up in driver XP you now get to choose from a selection of vehicles rather than being force-fed a single selection. They're little additions, but the kind that make a difference.
Yet aside from a certain eventual monotony and general lack of vitality, there was nothing much wrong with Forza 3's career structure, which explains why it's been winched out of that game and dropped underneath the bonnet of this one. It comes complete with upgrades, too, presumably to try and counter earlier criticisms - so you can occasionally find a Top Gear-inspired event requiring bowling pins to be knocked down, or an Autocourse stage involving the negotiation of cone gates on a circuit.
What you won't find is much in the way of new tracks, other than a small selection disappointingly handed out with the generosity of Ebenezer Scrooge. No doubt Turn 10 will happily exchange some of your Microsoft Points for more strips of asphalt via DLC when the time is right.
In the meantime, you've got a 500-plus car garage to tune. Forget for a moment the obvious offerings from Bugatti, Pagani, Lamborghini and their fratelli - some of the best Forza fun comes from grabbing the likes of a BMW 2002 Turbo by its flared wheel arches and squeezing an obscene bhp figure out of it while completely reworking its internals. When it comes to automotive upgrading, this is how it's done.