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.
Who makes Mazda cars? Founded in 1920, the Japan-based Mazda Motor Corporation makes approximately one million cars per year, with the vast majority produced in Japan. Consumers and experts alike consider modern Mazda cars to be safe and worth the investment, according to companies such as Consumer Reports and Edmunds.