Warning: automobile fuel economy neepery ahead.
Cheaper gas makes fuel efficient vehicles less appealing, in part because what makes a car more fuel efficient can make the vehicle more expensive. Diesel and hybrid versions of a vehicle costs more than their regular counterparts: you need gas to be expensive and to put a lot of miles on your car to come out ahead.
When we were car shopping last year, I ran the numbers on twenty different vehicles, looking for (among other things) the most economical car to drive — taking into account both the cost of the car and the cost of gas. (In other words, taking note of the fact that we might need to pay an extra $100 a month in car payments to save $20 a month in gas.)
A lot of that depends on how much you drive, and where. We don’t drive much — we averaged 16,000 kilometres a year with the Forester — and most of what we drive is highway driving. So fuel efficient options that really came into their own in city driving (hybrids) or lots and lots of long-distance driving (diesel) weren’t really worth the extra expense.
One question, though, was whether to get a manual or automatic transmission. Automatic transmissions, particularly continuously variable transmissions, now get the same or better fuel economy than stick shifts; in the case of CVTs, a lot more. While we preferred driving stick, and you could usually save more than a thousand dollars by getting a car with one, not every car came with one — and just maybe the automatic would save enough gas to be worth it.
I modelled our gas consumption on the following basis: 16,000 km a year, on a 75/25 split between highway and city driving, i.e., 12,000 km at highway fuel economy and 4,000 at city fuel economy. I calculated fuel costs at $1.35/litre, which did make sense a year ago.
On that basis, I looked at various cars — mainly Subarus, because Jennifer wanted all-wheel drive — to see whether the added cost of a CVT would be offset by improved fuel economy over the life of the vehicle. In every case, the answer was yes. Using Subaru’s estimated fuel economy numbers and $1.35/litre gas, the Impreza hatchback and XV Crosstrek saved less than $200 after ten years, the Forester around $200, the Impreza sedan and Outback a bit more than $400. The Legacy was something like $700 cheaper after ten years with a CVT.
Remember, this is over ten years: so between $12 and $70 a year. Some savings, not a lot. More if you drive a lot more than 16,000 kilometres a year.
Detailed numbers. The car we ended up getting, the XV Crosstrek, would burn 1,332 litres of gas per year (or per 16,000 km) with the manual transmission, and 1,204 litres with the CVT. At $1.35/litre gas, the CVT would save $172.80 per year. The CVT is a $1,300 option, so it would pay for itself in 7½ years or 120,000 km.
But this was at $1.35/litre gas and 16,000 kilometres a year. We’ve already put 22,000 km on this car since last May, and a lot of that was over the summer, when gas was sometimes more than $1.35/litre.
Now, of course, gas is running about 85¢/litre (around here, anyway), so the equation is a little different. The annual savings from burning 128 fewer litres of gas drop by $64, to $108.80, and the CVT would now need 12 years or 192,000 km to pay for itself.
All of which is to say that when the total cost of ownership for a new car can be something like $10,000 a year (car payments, insurance, maintenance, gas), a few tens of dollars per year in one direction or another amount to not very much. How you drive, and how much you drive, certainly matter more.