The CSIRO says petrol could reach $8 per litre by 2018, due to supply peaking, then declining. (Of this, even at a cost of $10 per tonne of carbon, only 25 cents would be an emissions charge.)

Jayne’s history blog notes that this month in 1940, “Petrol rationing was introduced, with motorists permitted to travel only 2,000 miles per year.”

Paying $8 per litre might do the same thing, of course. But it’s probably worth considering options to protect the supply and prices for people in regional areas. Even with the best public transport network in the world across capital and regional cities, they are likely to be stuck with car travel.

My current estimate, based on my roughly 100km driving per week and theoretical fuel consumption (7.98 litres per 100km in the ol’ rustbucket Magna) and $1.60 per litre, is I’m paying $638 per year on petrol. At $8 petrol, in my current car (which I’m planning on trading in for something smaller, soonish, like, when I get around to it) and current driving habits (which I’m expecting to reduce after 2009) it would be $3,194. Yeouch.

Work it out yourself:

• For cars up to 2003, get your vehicle mileage from Fuel Consumption database. Take the consumption figures and multiply the City figure by 0.37 and add the Highway figure multiplied by 0.63 to get the theoretical combined figure.
• For cars post-2003, use the Green Vehicle Guide, which will give you the combined consumption figure.
• Annual fuel cost = Kilometres per year / 100 * Litres per hundred km * Cost per litre