I'm not sure what your degree requirements are, but can you take a different angle?
So you're writing an article about hypermiling as a method to save gas. You are having difficulty finding people who actually employ these techniques, but I bet it would be pretty easy to find a few people who are disgruntled by their poor mileage (relative to their expectations).
You could introduce low fuel economy as the local problem, and then branch out to say "Hey Calgary, check out what this person from [Some city] is doing to improve fuel economy." The local pitch would still be plenty relevant, and may even better reflect the reality of the situation: regular people looking for better gas mileage out of their current ride.
But again, I could be way off. I'm not sure if your interviewees have to be hypermilers or if they can just be citizens dealing with high gas prices, but I hope this at least gives you some ideas.
If you're writing an informative piece, may I suggest informing SUV and truck owners of the
? It really puts mileage in perspective. Maybe it fits your needs.
Good luck with your work.