There’s no Fuel like an old Fuel

The BA

Since I acquired my licence in 1964 I’ve owned many different cars. If I had all the money now that I’d spent buying and maintaining them over the last 47 years, I’d be a damn sight wealthier.

But I won’t go there.

Instead I’d like to take a look at the economics of running a car from the point of view of fuel choice.

I owned a BA Falcon a few years back which I had converted to a Sequential Vapour Injection LPG system. At the time, it made a great deal of sense. I was refunded $2000 toward the conversion cost ($4500) and LPG was costing about 55cpl.

This meant I was running the thing at a notional fuel consumption of about 7 lit/100km (derived by halving the average fuel consumption to account for the price relationship between LPG and unleaded, an adding about 20% because of the lower calorific value of the LPG). The only downside was the loss of a bit of luggage space. One upside was an effective touring range of 1100km on the combination of both fuels.

It was a good buy at the time, costing me about $6 per 100km to run.

Converted motor - BA. Pick the extra hardware.

 The economics don’t stack up quite so well these days for LPG.

The rebate has been reduced to $1250 and will eventually be phased out. LPG is now costing 86 cpl, and the price will continue to rise through tax changes.  The relationship between unleaded and LPG prices is not as strongly slanted towards LPG.

Putting all this together, you end up with notional fuel consumption (for a dedicated LPG Falcon) of about 8.5 lit/100km. It’s good, but not as good as it used to be.

Another way of looking at it is to express the cost per 100km. For an LPG Falcon it is now $7.31. Unleaded costs you $13.20 per 100km. Back in the day of my BA, (as I showed above) it was $6 per 100km on LPG and about $14 for the same on unleaded. The gap was wider back then.

The other option is diesel.

To compare like with like, let’s look at the newly-introduced Mazda CX-5.

On unleaded, the cost per 100km (using Mazda’s figures) is $9.65. On diesel, it’s $8.42.

Given that you pay an extra $3000 for a diesel, and that it would take about a quarter of a million kms to recoup the extra, I don’t think diesel is a proposition.

Modern diesels are very driver-friendly, and have bucket loads of torque for overtaking, but I still don’t think it’s $3000 worth of convenience.

So that’s brings it back to the old fuel (unleaded).

As I said, there’s no fuel like an old fuel.