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Petrol v diesel: Which is more cost effective?

Which fuel is cheaper on balance - petrol or diesel? We weigh up the options.

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PETROL VERSUS DIESEL

Which Is More Cost-Effective?

As fuel prices skyrocket, more motorists are turning to diesel vehicles with hopes that they’ll lower their driving costs. Last year, diesel car sales surpassed petrol-run car sales for the first time ever. But are diesel cars really that much more cost-effective than petrol? New research suggests it depends on how much you drive.

Vehicle Costs and Resale

On average, diesel cars have a higher purchase price than petrol cars. However, the price of used diesel cars has risen so much that the price gap is significantly wider than in new cars.

The Typical Petrol-Diesel Price Gap
NEW CARS       New diesel cars run £1,300 more than new petrol cars.
USED CARS     Used diesel cars run £2,000 more than used petrol cars.
* For average new and equivalent 3-year-old family-sized cars.

 

Emissions

Motorists don’t need to be environmentalists to benefit from a car with lower emissions. Diesel cars typically have lower emissions than petrol cars, which means lower vehicle taxes in most cases.

CO2 Emissions
Petrol Car (Skoda Fabia 1.2 TSI Monte Carlo)     124g/km
Diesel Car (Skoda Fabia 1.6 TDI Monte Carlo)    109g/km

 

Cost of Fuel

Petrol prices are typically lower than diesel prices at the station. People tend to see diesel cars as a more economical option for their fuel economy, not for the price of diesel.

Retail Price Per Liter

 

Premium Unleaded Petrol

Diesel

September 2011

134.7p

139.2p

October 2011

134.0p

139.4p

November 2011

133.2p

140.3p

December 2011

132.1p

140.6

January 2012

132.9p

141.3p

February 2012

134.6

142.6p

March 2012

137.9

145.1p

 

Fuel Efficiency

Diesel cars typically have greater fuel economy compared to petrol cars. The Telegraph test drove two identical cars, which differed only by fuel type, 1,600 miles to determine which had the better fuel economy and driving experience. The diesel model outperformed the petrol model in all stages.

The Cars

  • Petrol Car: Skoda Fabia 1.2 TSI Monte Carlo
    1,197cc, four-cyl petrol turbo, five-speed manual transmission, front-wheel drive
  • Diesel Car: Skoda Fabia 1.6 TDI Monte Carlo
    1,598cc, four-cyl turbodiesel, five-speed manual transmission, front-wheel drive

Average Fuel Economy Test

 

Petrol Car

Diesel Car

Touring Speeds

37.4 mpg

44.9 mpg

Slow-Moving Traffic

18.1 mpg

26.5 mpg

Overall

27.5 mpg

38.0 mpg

 

Breaking Even on Your Investment

Because of the rising cost of used diesel cars and current fuel prices, it takes more miles of driving each year to make the cost worthwhile.

New Diesel Car      >>    You’d have to drive 6,000 miles a year to break even.
Used Diesel Car    >>    You’d have to drive 10,000 miles a year to break even.
* For average new and equivalent 3-year-old family-sized cars.

 

What’s Right For You?

With diesel fuel prices and diesel car prices both higher than petrol equivalents, determining whether driving a diesel vehicle is right for you may come down to how much you drive.

 

SOURCES: DAILY MAIL, GLASS’S GUIDE, SOCIETY OF MOTOR MANUFACTURERS AND TRADERS, THE TELEGRAPH, EU OIL BULLETIN, ENERGY INSTITUTE


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