Not long ago I received an email from someone who was 24-years old and living in Canada, he wanted to start a mobile oil change business and then retire young.
When he had heard I was in this industry during my business career and retired at 40-years old, he decided to give me a call.
I responded by telling him that although I retired at 40, it was not due to my mobile oil change franchise endeavors, indeed, the mobile oil change business was an afterthought.
In fact, I told him; I do not recommend the mobile oil change business unless you attack the fleet market only, fuel prices to get to customers is not favorable to the potential ROI, unless you have substantial volume at each stop on the route and schedule, qualified labor is also at issue, there are shortages of qualified techs and the proprietary oil of manufacturers is a problem.
The future may bring fewer reciprocating engines in automobiles as well.
I did not retire due to my efforts in the mobile oil change sector, it was one of many businesses, certainly not the best or most profitable.

He also asked; what possibility for success would there be in this mobile oil changing business in Toronto Canada?Why hasn't Canada taken off like the US?

Well, the Toronto Market would be excellent for this type of business, but it would not be a complete walk in the park, as nothing good in business ever is.
Why hasn't it taken off in Canada, because someone like this 24-year old never came along and did it; yet!