Expire is not really the right term; but effectively yes. In general a cheque older than six months will be considered stale-dated and will not be honoured. Reference the Canadian Payments Association FAQ.
SKYACTIV is a brand name for a series of technologies developed by Mazda which increase fuel efficiency and engine output. The initial announcement of the SKYACTIV technologies include new engines, transmissions, body, and chassis, which appeared in Mazda products from 2011.
With specially-designed 'Skyactiv' engines Mazda boasts some of the best gas-mileage in the class, and the car's 2.0-liter engine offers more performance than the 1.8s of its rivals. Opt for the manual transmission and it's even more fun--though does drop 1 mpg from the combined figure. 4. 2014 Nissan Sentra FE.