1JZ fuel type
 

All of the specs on the 1JZ say "fuel type: unleaded premium." Is premium required or is it just better for it? Also, is there an easier way to do the wiring on a 1jz? Ive heard they make a wiring harness thats like an adapter when installing in a mkiii. If there is such thing where could i find one and how much would it cost?

As far as premium fuel goes the higher octane is used to help prevent knocking/detonation. You can use lower octane fuel (many people do), but you increase the chance of real internal damage to your engine. For myself, I don't risk it where my GTE is concerned. It's a little more expensive per gallon, but less expensive than replacing pistons, valves, etc.

Not sure about the wiring issue, have to look around on that one.

That's pretty much what i figured but I wanted to be sure. My baby will get nothing but the best. Thanks for the help.

Yeah he's right on that matter. I also think that it's a little more expensive per gallon. I think I saw something on this forum about the wiring hareness.

Yeah the price difference is kinda self explanatory the better gas is always more expensive. As for the wiring I think there a few people on here that make a plug and play harness adapter you will just have to ask around.