err was reading this article about the renesis ...
http://www.autointell-news.com/News-...-02-04-p10.htm

Errr its 2.6 liters and it gets good fuel economy ? lol , what engine are they talking about ?

 

Old news - this is a repeat win, the Renesis won the 2.5-3.0 litre category last year, and also won overall Engine of the Year last year.

Mazda calls it a 1.3 - but the FIA and others for competition or tax purposes deem it to be a 2.6. This is based on number of power strokes per crankshaft revolution - since each rotor has one combustion event per revolution of the crank shaft, compared to a piston engine where each piston has one combustion event for every TWO revolutions of the crankshaft, the Renesis has twice the number of combustion events as a normal 4 stroke piston engine per crankshaft revolution - thus the deemed 2:1 displacement adjustment factor. This equivalent displacement factor has been discussed extensively here in previous threads, including the threads about the Engine of the Year awards last year.

Regards,
Gordon

 

This is also the same reason that for motorcycle racing (motocross in particular) 250CC 2 strokes run against 450CC 4 strokes.
(At first it was 500CC 4strokes, but the modern 4 stroke MC engine puts out way more power than 2 strokes at a 2:1 ratio).