True MPG – Most Economical Diesels

most economical diesels

Real-World Range Tests – Most Economical Diesels

Since launching True MPG What Car? has tested over 1000 cars in real-world conditions, using cutting-edge test equipment to establish the real-world fuel economy of new cars. What Car’s True MPG data has now been used by over three million visitors to the website since April 2012. Now, using our data, we have compiled a list of the most economical diesels you can buy today.

Make and model  |  Official (WLTP)/True MPG

1.  Vauxhall Astra 1.6 CDTi Ecotec  |  67.3/56.3
2.  Seat Leon 1.6 TDI 110  |  57.6/56.0
3.  Renault Kadjar 1.5 dCi 115  |  65.7/55.2
4.  Ford Mondeo 1.5 TDCi Econetic  |  78.5/53.7*
5.  BMW 420d Coupé  |  49.6/52.0
6.  Nissan Qashqai 1.5 dCi 115  |  53.3/51.9
7.  Vauxhall Insignia Grand Sport 1.6  |  55.4/51.8
8.  Kia Sportage 1.7 CRDi  |  61.4**/51.4
9.  VW Touran 1.6 TDI 115  |  61.4/50.9
10.  Audi A5 Coupé 40 TDI  |  54.3**/50.8

*Now deleted **NEDC data

Every one of these 10 most economical diesels achieves more than 50mpg, the best of them decisively so, with the Vauxhall Astra managing 56.3mpg. There’s a much wider scattering of numbers when it comes to the official combined fuel economy figures, partly because some figures were calculated on the old NEDC basis. Those tested on the NEDC/WLTP hybrid basis come closer to their True MPG figures, and the BMW 420d coupé actually betters it, by a useful 2.4mpg. Farthest adrift is the Volkswagen Touran 1.6 TDI; its 50.9 True MPG is disappointing against an official 61.4mpg.

True MPG uses a real-world test route but is conducted on test rigs at Millbrook to ensure test repeatability.