Think big yesterday, think small tomorrow

Engine downsizing has been in full swing for around five years as a means of saving gas and reducing emissions; in other words, meeting environmental targets. We're talking overseas, of course, not here, where it's rude to mention climate change to a government that prefers to ignore it.

As a result of engine downsizing, car makers have adopted turbocharging en masse and in the not-too-distant future you probably won't be able to buy a normally aspirated car, such is the move to forced induction. The reason for this is that with turbocharged engines, peak torque is developed at 1500-2000rpm, meaning much of the time these modern mills are revving half as much as their normally aspirated forebears. And lower revs means less gas is used. Rev turbos hard all the time and they will use more gas than a normally aspirated engine of similar size, but in general use they won't.

With the decrease in engine size and reduction in fuel use you'd expect worse performance but the opposite is true; with turbos you can maintain or even improve performance while also using less gas overall. Win-win then.

Actually, the future might be more a case of win-win-lose, at least if you're a person who is addicted to large vehicles. In the future, small cars will rule and there are good reason why big vehicles might be legislated out of existence, at least if New Zealand follows overseas trends. And we invariably do in the transport business because we don't make cars.

Petrol is slowly but surely running out. Yes, Big Oil is becoming more inventive about finding and extracting it, but the cheap gas has largely all been discovered and is being exploited while the harder-to-obtain gas awaits the onset of even higher oil prices, making its production commercially viable. Because the easy-to-find gas is running low, there's only one direction fuel prices will head. Smaller, lighter, and therefore more economical vehicles will invariably find greater favour.

As they already are. Superminis are becoming super indeed, and with trickle-down technology they're getting all the goodies that were once the preserve of executive cars, including things like alloy wheels, tinted glass, and remote control of audio, and higher tech stuff like twin-clutch gearboxes, voice-activated Bluetooth, iPod integration, and sat nav. They're no longer spec-poor zones.

Nor are they performance shy. They're increasingly lightweight and even the smallest offerings, the city cars, cruise effortlessly (if noisily) at 100kmh on B roads. They drive more like superminis than city cars too. This smaller-than-supermini class is growing. In New Zealand the smallest cars used to be superminis with the odd imported Smart Fortwo, but now in the city car or mini class there's Picanto, Alto, Splash, Barina Spark and, a recent introduction, Mitsubishi's Mirage. There's nothing much between these, though Alto is the smallest, slowest and cheapest, while with Mirage there's no choice of a manual transmission. Picanto is the only one with idle-stop and uses the least fuel as a manual (4.3L/100km overall), while the Mitsi is the most frugal as an auto (4.6L/100km). On a recent fuel economy run in relatively real-world conditions, the wee Mirage recorded best overall fuel use in mixed driving of 3.4L/100km.

The final straw for large vehicles may not be user choice but legislation. Town planners are sick of inner city traffic congestion and pollution, and a good way to begin cleaning up is by limiting the size of vehicles entering the heart of the bigger conurbations. There's less congestion when cars are 3.5m long than when they're 5m or more, parking is obviously easier, and emissions are also less, down around 100g/km. Even these small cars may eventually be restricted from entering the commercial hearts of major cities. London legislators are considering making the city centre a place for public transport and zero-emissions vehicles only.

The trend toward small vehicles is gaining pace. Large cars have been dying a slow death for years, with Commodore no longer the biggest seller in Australia, and there's a possibility that the next Falcon, a facelift scheduled for 2014, will be the last. Compacts and superminis are among the bestsellers at present, along with compact/medium crossovers.

Expect the trend of smaller engines and vehicles to continue with Ford introducing a Fiesta this year powered by a 1.0L turbocharged three-cylinder engine. This won Engine of the Year in 2012, and in 91kW guise Fiesta can get to 100kmh in a hasty 9.4sec, yet outputs just 99g of CO2 per km, and uses fuel at an average rate of 4.3L/100km.

Small may not be sexy in the car world, but in an era when fossil fuels are dwindling and inevitably will become more expensive, small cars with pint-sized engines are likely to become popular by default in the near future. So too will bicycles and scooters and perhaps then drivers will start to treat single-trackers with a little more recognition and respect. 

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