Drivers of diesel vehicles could be burning through as much as 75 per cent more fuel than stated by manufacturers, according to the findings of a worldwide study.
Carly Connected Car, developers of a 'manufacturer-quality diagnostic app', has released data collected from over one million vehicles showing a glaring difference between advertised and real world fuel consumption in diesel vehicles.
Carly’s Connected Car app, available for BMW, Mini, Mercedes, Renault and Volkswagen Group cars in Europe, can perform a manufacturer- quality diagnostic session and record actual mileage, fuel economy and fault codes logged in the car.
App user data shows a year-on-year growth of discrepancies in fuel consumption in every new model generation since 2004, up until 2017 where the difference appears to reduce slightly.
The most significant difference was found in diesel cars from 2016, achieving an average of 75 per cent higher consumption rates than stated in information given by the vehicle manufacturer.
According to UK registered charity and motoring research organisation, the RAC Foundation, the average fuel consumption for a new diesel car in 2016 was 3.7 liters per 100km. For a motorist driving 19,000km a year, this would be a cost of $2101 per year.
Considering the discrepancies found by Carly, this figure could instead be $3679, an additional cost to the motorist of $1,578 a year.
Carly 2018 Statistics Fuel Consumption Graph. Photo / Supplied
Overall, the study found that discrepancies were greatest in the three of the most popular vehicle segments in New Zealand; small cars, compact cars and SUVs.
The Carly app found drivers of small cars are using as much as 55 per cent more diesel and 35 per cent more petrol than the official figures, adding hundreds of dollars to annual running costs.
For compact car drivers the real-life diesel consumption recorded as 45 per cent higher than manufacturer figures. New Zealand's favourite segment, SUVs, were found to burn through through 45 per cent more diesel and 40 per cent more petrol than owners might expect.
The only segment of vehicle where manufacturer data reflected real-world results was Diesel sports cars where real world figures reflected the official data.
“There is an ongoing conflict of interest regarding fuel consumption. Over the years the regulations require less and less CO2 emissions, however, drivers want more powerful and luxurious vehicles,” says Avid Avini, one of Carly’s founders.
“With each new C02 reduction strategy, manufacturers have had to reduce fuel consumption, however due to tests being carried out in laboratories rather than the real-world, the data shows consumption to be improving.
"While it can be difficult for manufacturers to predict consumption, as it is very much dependent on individual driving style, a discrepancy of this size is of concern to consumers relying on manufacturer figures.”
-Driven