• Giant gets their gas at a better rate than I do. (and the truck they show gets better mileage than the one GM showed, a pointless bomber of a thing that gets about 10mpg in the real world)
• 15k miles/year means cycling 60 miles a day 5 days a week with two weeks time off.

Just the same, once I calculated my actual transport cost savings for bike commuting, including vehicle deprecation etc per year, I realized that I should have purchased a much more expensive bike