Whether you use synthetic or Dino, viscosity is the same relative measurement, or at least should be.
Lower numbers in multigrade oils traditionally have meant that they will flow easier at lower temperatures, so people usually will prefer a 10-30 in winter, and a 15-50 in summer, but it depends upon where you operate. 0W40 is reserved in most cases for sub-zero extreme operation, but the North American rep for Lubro-Moly, who lives in San Diego, prefers to use their 0W40 synthetic in his Suburban year-round.
Here's a little lesson on the principles of single weight viscosity for those who may be interested:
Use what your owner's manual specifically recommends for your climate conditions in Vancouver...
"We drive into the future using only our rearview mirror."
- Marshall McLuhan -
Northern California Wine Country...
"Turbos whistle, grapes wine..."