The latest version of MINI’s turbocharged Prince engine features variable valve timing, direct injection and a tall torque plateau that starts early and pulls the Cooper S forward with plenty of gusto. It even does heavier duty under the bonnet of the Countryman. The 2011 model year upgrades to the Prince engine brought adjustments to the power band and solved nagging issues some owners found with their R56s. So it’s little surprise that Wards has named the updated Prince to its Top Ten list of Engines for 2011.

Another new engine on this year’s list is the 1.6L turbocharged direct-injection I-4 that packs a mighty punch in the MINI Cooper S. With a specific output of 113 hp/L, this package quickly rose to the top of a crowded field of new small-displacement 4-cyl. engines in this year’s competition.

The latest “Prince” engine in the Cooper S is assembled for BMW by PSA Peugeot Citroen in Douvrin, France, and integrates BMW’s excellent Valvetronic fully variable valve timing system, which enhances power and fuel efficiency. Driven hard, this prince of an engine still musters better than 34 mpg (6.9 L/100 km) during our test drive.

The full list is as follows:

  • 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)

Beyond their list of honored engines, Wards went a step deeper in this article looking into the history and technology behind the current powerplant:

The ’06 model year brought a new all-aluminum 1.6L “Prince” I-4, jointly developed with PSA Peugeot Citroen, built in Hams Hall, U.K., and featuring BMW’s Valvetronic variable-valve-lift technology.

It bumped base power to 118 hp and torque to 114 lb.-ft. (155 Nm) with 26/34 mpg (9-6.9 L/100 km) ratings, while its turbocharged (not supercharged) direct-injected variant (without Valvetronic) pumped out a healthy 172 ponies and 177 lb.-ft. (240 Nm), with a temporary overboost feature good for 192 lb.-ft. (260 Nm). Fuel economy for the manual version was 25/32 mpg (9.4-7.4 L/100 km).

For ’11, BMW upped output again by adding direct injection and double VANOS (variable valve timing) to the naturally aspirated 4-cyl., plus Valvetronic and a new twin-scroll turbocharger to the S version.

That gives base-engine drivers 121 hp and 114 lb.-ft. (155 Nm) of torque and moves S owners up to 181 hp and 177 lb.-ft. (240 Nm), with the same 192 lb.-ft. (260-Nm) overboost feature. Manual-transmission coupe ratings now are 29/37 mpg (8.1-6.4 L/100 km) and 27/35 mpg (8.7-6.7 L/100 km), respectively.

The latest twin-scroll Cooper S 4-cyl. turbo earns BMW a second 2011 Ward’s 10 Best Engines Award (along with BMW’s 3.0L N55 turbocharged I-6). After averaging 34/35 mpg (6.9-6.7 L/100 km) in an ’11 Cooper S, “while beating it hard,” Ward’s editors exclaimed that it combines “stunning performance and superb fuel economy.”

We’ve said it before, but it’s good to hear it from other sources. The MINI hits a sweet spot in performance and economy that the competition has trouble matching, and that’s no small engineering accomplishment. The rest of the article is an interesting read if you’re not familiar with the history or motivation behind why MINI has gone the direction they’ve gone with these engines. But what might be most interesting is something MINI USA Product Planning Manager, Vinnie Kung, had to say about the future of MINI engines:

“Everyone has heard that we’re looking at different cylinder counts and different technologies,” Kung says. “It will be a process of optimization of everything we already have — if we can take Valvetronic to the next level, and lubrication systems and accessory drives, and electrify things such as power steering.

“I think in the next three years, when we introduce the next-generation MINI, you will see those technologies. And I would not be surprised to see another 20% improvement in fuel economy.”

A twenty percent increase in fuel economy at the same (or better) power range would be an amazing achievement of engineering. Given how far the MINI engine has come so far, I wouldn’t put it past the fine folks of Frankfurt. Cheers, Vinnie!