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RAC Editorial

Downsizing Your Car Engine

17 May 2012 at 14:13

Bigger isn’t always better. While large capacity engines have always traditionally delivered strong performance, there’s a new trend in the automotive industry that allows car buyers to have their performance cake and eat it without guilt: downsizing.

Put simply, downsizing involves reducing the cubic capacity of a car’s engine to improve efficiency – reducing CO2 emissions and fuel consumption – but with clever engineering and development that means it is delivered without compromising power and performance. In practice, this involves buying a new, more efficient car and selling your old car to accommodate this change. It should be noted that downsizing does not always mean buying a smaller car, instead the emphasis is on reducing fuel costs and road tax, so do not worry about losing the practicalities that larger cars can offer. We do, however, recommend researching efficient models to ascertain whether it will compliment your lifestyle. To support your downsizing, RAC Cars have established a free ‘Sell my Car’ service which helpfully guides you through the process of creating an advert. 

With road tax now based on emissions, engine downsizing and improvements in efficiency are a big deal for motorists. Consumers understandably want to pay as little tax as possible, as well as cut costs at the pumps through higher efficiency engines.

If you’re not already aware of downsizing but are feeling a little disgruntled at your annual motoring-related outgoings, take note: it’s a clear and proven way to help you cut your motoring costs.

Class by class: it’s happening across the board

Downsizing is a trend occurring in every sector of the car market. The new crop of city cars, for example, are generally powered by lower capacity units with fewer cylinders. The 2012 World Car of the Year, the Volkswagen Up!, uses a 60bhp or 75bhp 1.0-litre three-cylinder engine, returning a best of 68.9mpg combined with 96g/km CO2 emissions in BlueMotion Technology guise.

Compare that to similar vehicles of a decade ago, such as the first generation Ford Ka. This used a heavier, larger and thirstier four-cylinder engine, producing similar horsepower but returning significantly worse fuel economy. Here, downsizing immediately shows its benefits.

In the supermini and compact hatchback segments the story is the same, and Volkswagen has become something of a pioneer in the campaign for engine downsizing.

In the late 2000s the German firm replaced many of its 1.6- and 2.0-litre engines with a “twincharged” (that’s turbocharged and supercharged) 1.4-litre TSI engine. The results were 15 per cent more power than the 2.0 petrol of the time, with a five per cent reduction in fuel consumption.

The current 1.2 TSI engine in the Polo uses the same principal. The turbocharged motor produces 105bhp and returns efficiency of 53.3mpg combined with 124g/km CO2 emissions – compare that to the normally aspirated larger 1.4 petrol that produces only 85bhp, returning just 47.9mpg combined with 139g/km CO2 emissions, and it’s easy to see how downsizing can begin to save you money.

In road tax alone you’d save £20 per year – not much, but it all helps – then factor in the £159 lower fuel bills (over an average 12,000 miles per annum at a cost of 137.5p per litre of unleaded) and the savings begin to add up.

With RAC Cars you can sell your car for free to make room for a new, more efficient car - visit the RAC Cars Sell my Car page to learn more.

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