Wider, more supple tires might do better than that, the 26x2.2 rear on my tandem is 2k miles in, and probably has another 50% of its life left. Tandems are kind of noted for eating tires due to the loads on them.
I used to use GatorSkins - as they are perfect for London cycling. I used to commute 29 miles a day, 5 days a week, plus complete a 60ish mile ride on weekends - so times that by 47 weeks (5 weeks leave where I wasn't commuting) gives 9,635 miles. My gatorskins easily lasted a year, usually more - in fact I still have one of my London tires on my good bike, 7 years later (as the front tire) (I no longer cycle commute and only ride for leisure now.)
So I think those miles really are possible on a good tire. I used to use cheapo tires but ended up changing them 3 or 4 times a year and burning through inner-tubes.
The tandem and wider tires are not the cheap ones though, they’re Rene Hearse, roughly 90eur or so. I’d say they’re worth it, but they are about the same price as my last car tires.
So if we also assume that during the lifetime of the vehicle the cost of fuel you'll burn will be in the same ballpark as the cost of the vehicle, then the total cost of riding the bike will only be around 50% of using a car.
Normally, one assume about 24% efficiency in human pedaling, so that 1kJ of energy going forward = 1 kcal consumed.
Now, fuel cost is anyways a small part of owning a car. My 1k bike + food has lasted me years, while that's less than a newer car loses in value each month.
600kcal is ~200g of bread + 20g of butter. Bread costs about 5€/kg, butter costs 2€ / 250g so 600kcal is roughly 1,25€.
My car uses about 6l gasoline per 100km, current price is ~1,60€ per liter, so 20km need 1,90€ of gasoline.
So if I just eat cheap food riding a bike is cheaper.
If I eat at McDonalds, then 600kcal is a hamburger with medium fries, which costs ~4,50€. Then taking the car is cheaper.
This is quite surprising!
