In Canada it's the Green Levy tax:
- At least 13, but less than 14 litres per 100 km: $1,000
- At least 14, but less than 15 litres per 100 km: $2,000
- At least 15, but less than 16 litres per 100 km: $3,000
- 16 or more litres per 100 km: $4,000
For reference my 22 GT500 was $2000 at 14mpg combined, and the non z06 is stating 17.5-18.5mpg which puts it in the 13-13.5L/100km range aka $1000