This is actually two different fares, one on AC (PRCT28) and one on AI (ZDXT2YVP - I believe there are different fare basis based on day of departure, I think this is the cheapest). I am pretty sure that AI deeply discounted their business fares on this route around mid-may and AC cut to compete.

AC (PRCT28)
Ticketing Deadline - May 31 (unless extended to continue to compete with AI)
1 free stopover per direction in most major Euro gateway cities; 1 paid stopover in each direction in another dozen Euro cities
Valid on the AC non-stops from YYZ and YUL to DEL which have not been discounted all that often lately
Fares are between 4050CAD and 4300CAD RT for the most part
Probably possible to get fairly creative with the routing to maximize mileage. A fairly simple example is below - YVR-AC-YYZ-AC-DXB-AI-DEL-AI-DXB-AC-YYZ-AC-YVR. Credited to AC this works out to 30,352 SQM or 13.58cpm (in USD 9.89cpm). I booked YVR-YYZ-DXB-DEL-MUC-YVR. Not as many miles (especially with LH P legs crediting at a substantially lower rate) but I get to go to Oktoberfest on the way home.

Dates are available but the cheapest ones seem to be in September.



AI (ZDXT2YV)
No expiry date that I can see so hopefully AI keeps it around and AC keeps their fare down to compete
Routing is much more restrictive. It either requires the AI non-stop YVR-DEL (if you dare) or permits YVR-AC-LON/FRA-AI-DEL. From a cursory look, there seems to be much more availability on the non-stop than the others.
Unlimited stopovers at 55 CAD each (if you can find the routing)
Fares vary but I have seen them as low as 3450 CAD but more often in the 3700-3900 CAD range.
Probably one of the cheapest Western Canada to India fares I have seen in a while




Enjoy getting creative with the routings. Post the best mileage run you can construct.