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.
Mazda CX-5: 29 mpg. Just like the Honda CR-V, the Mazda CX-5 is one of the most efficient mainstream compact crossovers around. Unfortunately, it achieves its best fuel economy (26/35 mpg city/highway) when paired with a rather anemic 2.0-liter four-cylinder engine and manual transmission.