The EQUA Mpg gap increases further in 2016

This year’s round up of EQUA fuel economy data shows a five percentage point increase in the gap between official and real-world mpg, reaching 29% in 2016.

Official mpg figures averaged 60.7mpg in the year, the highest we have seen since we started recording in 2011. This is an increase of 9% on 2015’s figures, which stood at 55.7mpg; however, real-world mpg reached just 42.3mpg. On a like-for-like basis, this represents a 3% increase on 2015.

Air conditioning

With air conditioning now widely available in cars, in 2016 Emissions Analytics updated all its mpg results to include the effect of air conditioning on fuel economy. Results are now expressed to reflect manually adjusted air conditioning (not automatic climate control) switched on at 50% of maximum throughout the test. This increases fuel consumption typically by 4%.

Incorporating the use of air conditioning, the gap between official mpg figures and real-world EQUA Index Mpg has risen to 29% on average, with the largest gaps well exceeding 40%. This increases to 75% below the official figures for hybrid vehicles that have not had their battery charged and are running purely on the ICE.

Can regulatory change reduce the gap?

From 1 September this year the World harmonised Light duty vehicle Test Procedure (WLTP) will be introduced to certify the carbon dioxide and fuel economy of cars. Work started on this around 2008 and was originally intended to be a worldwide certification standard. However, with the passing of significant time and the withdrawal of North America from the process, it has become less relevant.

It will still be an improvement on the existing type approval process, which incorporates the New European Driving Cycle (NEDC), largely due to the removal or restriction of loopholes in the procedure.  However, the test cycle itself is not much more representative of real-world driving, as it remains in the laboratory with no changes in elevation and still modest acceleration rates. Our prediction, also consistent with modelling from the International Council on Clean Transportation, is that the current mpg gap of 29% and the CO2 gap between official and real-world of around 40% will approximately halve. So, a significant gap will still remain.

Crucially, it has yet to be agreed when and in what way the WLTP results will be made available to consumers. In the meantime the EQUA Index is available for anyone wishing to find out the on-road fuel economy of both Euro 5 and Euro 6 vehicles.

The Sunday Times: “UK approved Fiat’s ‘dirty diesel’ engine”

In an article dated January 15 2017 by Jonathan Leake, Environment Editor at The Sunday Times, Emissions Analytics’ CEO and founder Nick Molden is quoted as saying: “When a vehicle passes laboratory tests but shows such a different performance on the road you have to be suspicious about the technology.”

This comment was made in response to the news that Fiat Chrysler are being investigated by the US’s Environment Protection Agency and the UK’s Department for Transport due to significantly higher real-world NOx emissions than those emitted during laboratory testing.

The EPA has issued a ‘notice of violation’ to Fiat Chrysler – listing alleged devices including timers which are said to switch off parts of the emission control system after the engine has run for the short time needed to conduct tests -for failure to disclose auxiliary emission-control devices, or AECDs, which is a violation of the Clean Air Act.

Emissions Analytics found that Fiat’s 500X MultiJet with a 1.6-litre diesel engine, emitted 14 times above EU and UK limits. The Fiat Doblo van was even worse, with emission 17.8 times above the legal limit, even though it has passed official tests.

For more data on Fiat, and other vehicles visit the EQUA Index.

Weight costs fuel

2WD vs 4WD