It's 1.30am but I just can't go to bed without expressing my amazement at how incredible Mad Max looks, nearly 30 years after it was made. I just finished watching it on TV, and far from taking me back to the days when I was a teenage Mad Max obsessive, this viewing shed a whole new light on what's great about the movie. Like most teenage boys in the mid-1980s, I came to this and the 1982 sequel because of the car chases, the violence, the leather, the freaky characters, the futuristic setting, the leather (did I mention the leather?) My first ever visit to London's legendary Scala Cinema in King's Cross was to see a Mad Max triple-bill when I was 15. But now I see the film has virtues I wasn't equipped to understand as I gazed lovingly at the screen back then, probably forgetting about my acne and imagining I was Mel Gibson. (Certainly I remember walking back from a friend's house to my home in the same sleepy village, and actually imagining I was Mad Max as I strode down the centre of the deserted road.)

Ok, coherent thought can only be minutes away from deserting me, so I'd better cut to the chase (how appropriate) and tell you what's so good about this crude, cheapo B-movie-style exploitationanza. Well, for starters, the fact that it's a crude, cheapo B-movie-style exploitationanza has insulated it pretty sturdily against the cinematic fads and phases that have since come and gone. The stark, low-budget, make-do look of the film increases the grittiness - it's like those early David Cronenberg gorefests (Shivers, Rabid) where it really did seem like anything could happen because it was all clearly operating outside conventional movie etiquette. In Mad Max, that is combined with the very eerie, desolate mood that permeated the most interesting Australian New Wave films of the 1970s - think of Peter Weir's Picnic at Hanging Rock and The Cars That Ate Paris, or the underrated Fred Schepisi's The Devil's Playground and The Chant of Jimmie Blacksmith (one of the most scalding, upsetting films ever made).

All those films seem to take place in a land that time not only forgot, but tried to bury alive. This works to the benefit of Mad Max, which is billed as happening a few years ahead of whenever the viewer happens to be watching it (I love that device - doesn't Splash, after the flashback prologue, use the title 'Cape Cod, yesterday'?). So the sense of isolation that was presumably imposed by the budget - they seem to be shooting on back roads, backwaters, the back of beyond generally - creates this dislocated atmosphere that makes the film look far better now than it would do if they'd had the money to build futuristic sets. (Look at two Paul Verhoeven films, RoboCop and Total Recall, to see how poorly time sometimes favours big budgets. Or compare Star Wars, which looks so cheesy, with THX-1138, where, again, frugality has equalled longevity).

Other things I love about Mad Max: Mel Gibson before the mannerisms had kicked in; the fact that Max's big 'turning point' scene (when he decides to go vigilante after the murder of his family) is conducted while he is wearing pyjamas - isn't that fab? If only more action heroes would wear pyjamas...

(Reminds me of one of my fave jokes: How do you know when there's a monster in your bed? Cos he's got a big 'M' on his pyjamas.)

Also, the director George Miller's beautiful, expressive, almost Cocteau-esque way with film language: the wipes, the endless dissolves-within-dissolves (there's a breathtaking one that is used when Max visits his horribly burnt friend Goose in hospital - Miller uses the dissolve between Max looking anxious and Max looking horrified to avoid showing us Goose's face, though Gibson's expression is equally chilling). And that great 1970s thing, often found in Nicolas Roeg (especially Performance) or Robert Altman (especially McCabe and Mrs Miller) where the zoom magnifies the film stock to such an extent that the image actually becomes coarse-grained. I also loved the spare, no-nonsense editing - there's no fat on this movie - and the way Miller throws in a virtually subliminal shot of bulging, bloodshot eyeballs (whose eyeballs? I dunno) during moments of horror.

The movie gets the job done, quickly and without undue histrionics (the emphatic score only underlines how lean the action is). And it leaves a rare chill in the air, as much due to what it doesn't show (the economic way Miller shoots the murder of Max's wife and son, so that all we see is a baby's shoe and a coloured ball in the road) as to what it does. Tim Burns, as the deranged Johnny the Boy, is frighteningly good in that final scene, where he's laughing maniacally and pleading with Max. The end-note of cultivated sadism is hard to dispel.

Accidental plus-points include the villain's resemblance to Gary Glitter, and the appearance in the cast list of one David Cameron, playing 'Underground Mechanic'. So now we know where he gets his hoodie-love from. I loved also seeing the late Sheila Florance, so great as the prune-faced Lizzie in the official Worst Ever (and therefore Best Ever) prison drama, Prisoner Cell Block H, turning up here in calipers, wielding a double-barrel shotgun. Dandy Nichols couldn't have done it better. Viva Australia!