“There is no substitute for cubic inches” [of displacement], they used to say during the muscle car era. 427, 440, even 500 CID and more, with horsepower ratings equivalent to the displacement, propelled the land-yachts of yesteryear.
Those displacements equate to 7 liters, 7.2, and 8.2 liters. Gasoline consumption was unimportant, because the price per liter at the pump ranged between 10 cents and a quarter.
Such was the situation before the oil crisis of 1973.
Small cars were new to North Americans; the first compact from the Big Three was the K-car, heralding the coming of front-wheel-drive (FWD) at the same time.
Smaller cars simply need smaller engines, but the lack of power was something few drivers liked.
Computerization, adjustable valve timing, fuel injection, and other advances gradually compensated for the reduction in engine size and the reduced power. Over time, engines became more powerful again, but with a seven-year cycle for a new model, it takes many years to see any great change.
The new millennium finally brought the realization of what burning carbon fuel does to our planet. Consequently, government rules for emissions are getting more stringent as time goes on.
Since emissions are directly linked to fuel consumption, engine downsizing is now the only way to reduce fuel usage and thereby emission. No one is happy with an engine that has pony-power instead of horsepower, so engineers are using new ways of extracting more power from smaller displacement engines.
Long known from sports- and racing cars (racing improves the breed) is the fact that supercharging or turbo-charging increases power. As engines are getting smaller in number of cylinders and displacement, additional air is being ‘pumped’ into the smaller cylinders, so more fuel can gain extra power from less displacement.
Various types of air pumps were used even before the first automobile drove on our streets.
Air pumps, such as superchargers are mechanically driven by the engine and force extra air into the cylinders as soon as the throttle is pressed for more power. The turbo-charger, on the other hand, takes a few moments to spool up, but is driven by exhaust gas, in effect getting a free boost. Conversely, the supercharger takes considerable power to turn. Electric e-chargers are the next development , combining the advantages of super- and turbo-chargers.
Combining a large and a small turbocharger on some of the new, downsized engines negates the loss of displacement; combining a supercharger and turbo-charger is the way other carmakers recover horsepower, and variable impellers serve best in yet other applications.
Everything is a compromise, and engineers weigh the options to extract the best from what they have to work with.
As the industry develops and introduces yet another new model of alternative transportation -car or truck- to lessen fuel consumption and emission, new combinations of downsizing and upgrading keep drivers wanting better acceleration and more power and speed.
Always ahead of his time, prominent writer Henry Miller said, “Life is 440 horsepower in a 2-cylinder engine.”
Nissan is getting close with 400 horsepower in a 3-cylinder racing engine. Turbocharged.
Audi is getting even closer with 600 horsepower in a 4-cylinder racing engine. Turbocharged.
Ford has a complete family of family-car engines, designed for durability and economy, branded EcoBoost. Turbocharged.
That family ranges from a small 3-cylinder and all the way up to 380 horsepower in a small V6; the mass-produced one-liter (displacement) EcoBoost engine develops 140 HP.
Quoting Ford: “The Fiesta Zetec S engine pumps out 140 horsepower, which makes it the most powerful 1.0 liter [Note] production car ever manufactured. That’s more power per liter than a Bugatti Veyron, although the Veyron has considerably more liters [displacement] on offer.”
When this writer was initially working with engines, 100 HP per liter was only made by pure racing engines; the above-mentioned 3-cylinder engine develops more than 200 HP in racing trim, still a production engine.
The kind of performance of the muscle cars now comes from less than half the displacement, but with more than double the fuel economy. [link shows in row 3 turbo-charging schematic by Ford]
“Horse-power named Mustang” – how fitting.
Life and technology is a circle of losing and gaining.
Note: Volkswagen also has a ‘one-liter’ production car, but that is a different liter story; See the article of October 21, 2013.