JZX NZ

So. My 1J uses gas. Oh that's normal. But. I put 50bux 91 into it. Got it 4days driving. Might I add with quite a heavy foot as I just got the car. Recently put 80bux 98 into it. Got it 2days driving with most of the driving being on the motorway. What the..

02 Sensor?

Yeah probably just due for a good service. Replace o2 sensor as its probably the original one that came with the car. Do your air/fuel filters, spark plugs etc. And if you're running a stock exhaust, check that the cat converter isn't blocked up. All the above can affect fuel economy.

For comparisons sake I put $50-60 of 95 into my car (2jz n/a manual), that lasts me a week, and I do quite a bit of driving.

Would probably look at your fuel filter aswell. Plus mixing fuels like that doesnt really do much to help the engine so economy will be going down something wicked. Pick an octane (with 1j and 2j recommended is minimum of 95) and stick with it and that will solve a little bit of the issue.

Is it idling rough, high/low at idle or surging?

My fuel economy is also really variable.

1 day I used $130. Another time I went for 5 days without using any.

I also find $/day a really bad measure

Fill it full.. drive it 100km and fill it again and tell us how many litres it uses.

And yes, minimum on 95