I am in New Zealand, we get 91 octane, and 96 octane.
What should I be using? I only just got this car and have no idea. Should they be running on higher octane? or a fairly low one.
Btw, it is a 1983 engine, EFI.
It all depends. You folks down under have a different way of computing your octane than us folks in the U.S.(saw that somewhere on this forum a few weeks back...). I'm assuming that the 96 octane you have is similar to our 91~93 octane, and of course your 91 is probably our 85~87...
Personally, I like using the highest octane possible, it gives a little more power than the lower stuff but in all reality, you can use the lowest grade that doesn't allow your engine to knock or ping. If you use the lower stuff, make sure you listen for the familiar "marbles in my engine" sound. Run the A/C while you are listening for it, as the extra power consumption of the compressor will make the engine ping a bit more. If you don't hear it on a warm day, the octane you used is good enough. If you do start hearing the pinging, immediately(within one tank of fuel) go to the next level up. Try it again with that grade and if the same thing happens, go up again till you get rid of the pinging.
Of course, if you don't mind paying a bit more per gallon (or is it litre down there?), then just run the top stuff! There's nothin' too good for our Supras, right??? :lol: You'll probably notice slightly better mileage and(or, depending on your driving!!!) power.