WHEN IT COMES to petrol, I reckon the oil companies have been holding us to ransom for decades and can be more slippery than governments.

What I get cranky about is the extent to which modern fuels can be a problem in older cars. New fuels in new cars? No problem, as they’re designed for it. The sorts of cars we like, however, often need work to cope. Everyone loves a GT Falcon or an SL/R Torana, but they are anything but happy with some of the stuff that comes out of the bowser. A good example is ethanol blend fuels. We’re told how fantastic they are and how they perform better. They don’t – certainly not in older machinery.

Ethanol attacks a lot of the seals in a typical carburettor and you can have a car running badly in a matter of days and it will cost money to fix. Of course the oil companies are not keen on getting involved in this, so you are on your own.

It’s a bit of a minefield and deserves thinking about. Ideally your old car is set up for modern fuels to the extent the valves have hardened seats, while the ignition timing and jetting is set up right. In general, they’re going to like higher-octane fuels, though the situation will vary from one vehicle to another.

For example, the Unique Cars Chevrolet C10 tends to foul plugs on 98 at idle, and is happiest with 95, while the Ed’s old Kingswood (which has had relatively recent carburettor and ignition work) prefers 98. In any case, work out what it needs and get advice from your workshop if you’re not sure.

There is a difference between brands of fuel. I’ve had some poor experience with Shell, while I and Tony Whelan, the owner of Wilson Carburettor Service in Melb, lean towards BP as first choice and Caltex second.


If you’re out and about with the car, there will be times when your first choice of fuel isn’t available. It’s no big deal, but do make use of the first opportunity to dilute it down with the good stuff.

While I’m on the case, I’m not a fan of additives and the like – set the car up properly.

Really, you should aim to have the fuel system in good shape – no leaks – and the car regularly topped up with fresh juice. These days petrol can go off in a major way in a month or two. Let it sit for a few years and you will be surprised at just how destructive it can be.

So the kindest thing you can do is not just jump in and start the engine every blue moon, but pump up the tyres, take it for a proper drive and stick some fresh fuel in it. Believe it or not, the investment in time and petrol will be a whole lot less than the consequences of a neglected car.