Whether the government succeeds in killing off the internal combustion engines in 15 years or not, you can bet your spare kidney that newly-built petrol-burning power is going the way of the dinosaurs much, much sooner than any of us would like. But hey, maybe that's alright - slightly older engines, built in that sweet spot between antiquity and modern production techniques, when manufacturers didn't sweat so much over a stray gram of CO2, are better anyway. Here are the ones we recommend stockpiling for less enlightened times...
Alright, granted - the B-series (specifically the B18C6 found in the Integra Type R) is actually nirvana-inducing, and the idea of peak torque appearing at 7,300rpm is now so whacked-out crazy that it's tempting to include it on general principle. But there simply aren't that many DC2s in the country and we'd rather keep this list semi inclusive - so the K20A2 gets the nod. The naturally-aspirated 2.0-litre motor has been the gateway drug to the VTEC way for very nearly two decades, and while Japan may have snaffled the higher spec K20A all to itself, the Swindon-built EP3 Civic is rightly deemed a legend to everyone born after 1980. Yes, they've been going up in value recently (surprise, surprise), but you can still get a very decent example for around £6k. No excuse, then.
Audi's decision to remake a turbocharged inline five - the engine which helped make it famous - was obviously inspired. Even a half decent attempt would have succeeded, such is the warbling offbeat draw of 1-2-4-5-3. But Ingolstadt saw to it that the resulting motor was heartthrob-good and more than capable of making its often staid product line seem like must-haves. Not for nothing, it also built the thing like a bloody bank vault, which meant that its rampant tuning has continued to this day. The 2.5-litre unit now produces 400hp at 7,100rpm, and that's by no means the limit - the Litchfield RS3 Dan drove a couple of years ago liberated 507hp with nothing more than a remap and intercooler. Of course because the motor lives exclusively in RS models, it isn't possible to possess it for peanuts - but less than £20k will still tick it off the bucket list.
Mazda 13B-MSP Renesis
A motor which offers a combination of compact dimensions, inherent balance, an excellent power-to-weight ratio and the potential to be tuned to within an inch of its life. Sounds like a dream, doesn't it? Well it was, until Felix Wankle came along. There have, of course, been many various takes on what is better known as a rotary engine. When it comes to adding one to your post-petrol pantheon of preservation, however, only one candidate comes to mind: the Mazda Renesis. Sure, it'll drink fuel and oil like they're going out of style - appropriate, given the circumstances - and it could never be described as torquey. But with peak power not arriving until 8,200rpm it'll have you grinning like a lunatic as you chase the redline all the way to the nearest government-sanctioned petrol depot. Offering as many foibles as it did revs, the 13B-MSP may not be the most well-rounded engine on this list, then, but it's certainly a unique prospect. What's more, decent looking, relatively low mileage examples of the Maxda RX-8 which it came plugged into can be had for practically nothing, making it more a question of why wouldn't you than if you should.
Has any volume manufacturer produced as many virtuous engines as the mighty Bayerische Motoren Werke AG? Certainly there are several that could have justifiably made this list - there was office-based support for both the S50 that preceded (and formed the base of) the S54, and the S65 V8 which succeeded it. Matt Bird was so upset the S85 V10 - an outlier in BMW's normally rigid insistence that performance engines evolve from regular ones - didn't make the cut, he flew to the Dominican Republic in protest (or possibly for a holiday). But it's the S54, naturally-aspirated and with six cylinders arranged the proper way, which gets the nod. Why? Well, partly because it powered the E46 M3, a car that BMW has been trying (and failing) to replicate ever since, and partly because it produced 338hp at 7,900rpm and made you live every revolution. Sadly the days of picking up a decent one for book tokens is coming to an end. Expect to pay north of £20k for a seriously good one. And more than double that if you want a CSL.
You can't assemble any collection of brilliant engines without including a Ferrari V8, and what better way to experience one than the F136? Its eight victories in the International Engine of the Year awards speak for themselves, but it's the breadth of applications to which the motor was applied which make it such an appealing selection here. A 4.7-litre, cross-plane cranked version can be found producing up to 460hp and 384lb ft of torque in Maserati's Quattroporte S and Gran Turismo S, both of which could certainly now be described as accessible in one form or another. Seeing Ferrari's flat-planed installation on your driveway might set you back a little more, but from the 4.3-litre F430 to the 4.5-litre 458 Speciale, there's really no bad way to do so. With the wind in your hair and nothing to separate you from its spine-tingling howl, though, this 458 Spider would be our pick of the bunch.
From the rasping 6.3-litre V8 in the C63 to the oversquare revvability of the 190 E's Cosworth-tuned 2.3- and 2.5-litre motors, Mercedes has produced some masterpieces in its time. Why the M120, then? Two words: Pagani Zonda. The hypercar has used three different versions of the aluminium-blocked behemoth, displacing 6.0-, 7.0- and 7.3-litres respectively. In those applications it commonly produced between 550 and 680hp, although it made as much as 800hp in the Zonda Revolucion. Unfortunately, unless you find a spare couple of million down the back of the sofa, you're unlikely to be lucky enough in a Zonda. But never fear, because that doesn't mean you can't get a taste of that sweet, sweet, V12 nectar. A 6.0-litre, 48-valve example of the powerplant was sold in a variety of Mercedes flagships throughout the 1990s. Cars like the W140 S-Class and R129 SL may not be pursued by gaggles of excited snappers outside Harrods, but can be found second-hand for the price of a service on the Pagani. This 85,000-miler looks not only to be a prime candidate for a spot of bargain barging, but one of several now-budget Mercs which, with a little fettling, are just waiting to have their full aural potential unlocked.
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