It's not. Australia calculates fully loaded car costs at $0.72AUD/km. If you add up depreciation, registration, insurance, servicing, fuel, repairs and amortize it the numbers check out.

Surprisingly, ATO is rather generous with this one. Few posts below is my estimate for an oldish car, running the numbers for the "new small car every 3 years" model I still end up significantly below A$0.72. The averages must include luxury cars, which doesn't make much sense.

That misses the biggest cost, parking. If you work in the city like most people thats easily $15 down the drain.

That must be "average body temperature in the hospital, including the morgue".

In Germany you can tax deduct 35-40 Eurocents/km for you commute. That's reasonably close to the Australian number. The AAA also estimates similar numbers: https://exchange.aaa.com/wp-content/uploads/2019/09/AAA-Your...

Just ran the numbers for my 10 year old Honda and my 15,000 km per year.

Accounting for depreciation, interest, insurance, actual service bills and petrol, I ended up with A$0.25 per km and A$4150 per annum, so ATO-sanctioned business travel compensation always rightfully seemed to be a handout to me.

A new BMW can easily cost 6x as much, hence "average body temperature".

In the US, business auto deduction is around 52 cents per mile.

An oldish paid-off relatively inexpensive car will absolutely do better than that on average. But it's actually not unreasonable that the business deduction bases costs on something like a late model leased midrange sedan like a sales rep might use to drive clients around.