Mazda 2.3L Miller-cycle DOHC V-6

A few years ago, there was a lot of talk from interior stylists and designers about a "surprise and delight" strategy - offering the customer features that are thoughtful and more than is expected.

Mazda Motor Corp. ought to make the pitch for the Miller-cycle V-6 as the largest single lump of surprise and delight in the business. Besides the hugely overlooked Miller, only two other engines have been on the Ward's Ten Best list all four years since 1995.

Mazda's power-packing Miller-cycle is such a formidable engine primarily because of its devilishly effective technology (the Miller-cycle perpetually is the highest scoring engine in the "technical relevance" portion of our Best Engines competition) and its butt-kicker-in-a-tuxedo driving characteristics.

How much techno-vation do you want? Mazda's Miller-cycle has it. The name implies a unique operating cycle that, in essence, is like variable valve timing in reverse. Typical variable valve timing engines employ some mechanism to alter the opening of intake valves - or both intake and exhaust valves in some high-performance examples - so that the opening of the valves does not have to be dictated by a single, compromise setting that balances power delivery, driveability and emissions.

The Miller-cycle engine also employs variable valve timing, but in this case it actually affects the closing of the intake valves. This happens during the compression stroke in order to ease the work the engine has to do against itself - commonly known as pumping losses.

All we know is that it works. This sophisticated approach to garnering more engine power from a smaller-displacement package is enhanced by a Lysholm screw-type supercharger to pack in a denser

air/fuel mixture, a critical point because the compression event is of a shorter duration than in conventional engines.

Mazda engineers doubtless got plenty of overtime in developing the Miller. What the driver gets is a stomping 91 hp/L and all the midrange torque one would expect from at least a largish V-6 - yet the Miller-cycle engine is just 2.3L, a displacement more common for 4-cyl. engines.

Mazda's Miller-cycle continues to surprise and delight our Best Engines testers each year. We only wish that Mazda, or ever-more-involved corporate parent Ford, would find more ways to use this innovative and refined engine. The Millenia is a wonderful car, but we can't help thinking that new Cougar could be a lot of fun with the Miller-cycle underhood.