Influential US automotive magazine Ward's has named its best ten engines of 2011, placing electric motors on the list for the first time.
The list is one of only a handful of engine rankings and traditionally sees engines from new US, German and Japanese models battle it out for places.
Both the Nissan Leaf and the Chevrolet Volt earned a place on the 2011 list, with Ward's editors judging them among the top ten of 38 vehicles that were evaluated.
Ward's Drew Winter described the 2011 list as "the most diverse mix we've ever had, as well as the most technologically advanced."
The 17th edition included only two engines from last year's list (the Audi S4's 3.0L TFSI Supercharged DOHC V-6 and the Volkswagen Jetta's 2.0L DOHC i-4 Turbodiesel), meaning that eight were new or heavily modified, the largest turnover in the history of the ratings.
To be eligible, the engines had to be fitted to US-specification vehicles, on sale no later than first quarter 2011 and priced no more than $55,000 (€41,600).
German automakers accounted for four of the engines, US automakers three and Korea, Japan and Sweden one.
This year's winners and the applications tested:
* 3.0L TFSI Supercharged DOHC V-6 (Audi S4)
* 3.0L N55 Turbocharged DOHC I-6 (BMW 335i)
* 1.6L Turbocharged DOHC I-4 (Mini Cooper S)
* 3.6L Pentastar DOHC V-6 (Dodge Avenger)
* 5.0L DOHC V-8 (Ford Mustang GT)
* 1.4L DOHC I-4/111kW Drive Motor (Chevrolet Volt)
* 5.0L Tau DOHC V-8 (Hyundai Genesis)
* 80kW AC Synchronous Electric Motor (Nissan Leaf)
* 2.0L DOHC I-4 Turbodiesel (Volkswagen Jetta TDI)
* 3.0L Turbocharged DOHC I-6 (Volvo S60)
Data from Ward's http://wardsauto.com