background info

- d16a3 engine, 4speed auto
- ram intake, 2" catback
- approx 650-700km of driving per week

due to the amount of travel that i do, and the increase in petrol prices, i want to squeeze every km/litre that is possible.

i've got an old school SAFC lying around, waiting to be hooked up. i can adjust at 5 different rpm set points. i also have a jaycar digital air/fuel display.

questions
- should i still get it tuned on the dyno?
- am i able to tune it using just the air/fuel display?
- what should be the optimum air/fuel ratio in terms of consumption, performance etc
- will i need to have different settings if i use unleaded, premium or 98ron?

sorry for the loads of questions. thanks in advance