Originally Posted by lexiss_sc400

Actually it does harm the engines... after prolonged usage of 87 octane on the V8 (in particular) leads to the destruction of your knock sensors, which are $2xx something dollars each, yes you’ll need 2. Then the labor of having to remove the whole intake manifold to get to the 2 sensors...for a pro it’s a minimum 2-hour job. It could take hours for someone who doesn’t know what their doing.
And finally when the sensors go bad and u don’t replace them they will no longer tell the engine to “retard” the timing and thus you begin (and its not anything that will happen with in a day, it will take time) to slowly mess-up you various engine components....

Originally Posted by LazyAlex

ok well..i know the gauges say "premium unleaded only" and so does the gas lid...but is that what they recommened? or what it needs becuase...premium here is $3 a gallon.,..and ya..thts $$..so i was just wondering..i mean..i been pumpin premium..but..if it should be ok to pump regular..or plus..ima start doing that..till gas goes down alittle..any idea? thanks

Originally Posted by lexiss_sc400

Actually it does harm the engines... after prolonged usage of 87 octane on the V8 (in particular) leads to the destruction of your knock sensors, which are $2xx something dollars each, yes you’ll need 2. Then the labor of having to remove the whole intake manifold to get to the 2 sensors...for a pro it’s a minimum 2-hour job. It could take hours for someone who doesn’t know what their doing.
And finally when the sensors go bad and u don’t replace them they will no longer tell the engine to “retard” the timing and thus you begin (and its not anything that will happen with in a day, it will take time) to slowly mess-up you various engine components....

In your case you’re running a 1jz so I can’t and won’t talk about that because I really have no idea about those engines. But with the mechanical knowledge I have and with the time I’ve spend working on the 3 Lexus V8s we have in my house, I’ve learned a few things….


In my opinion if you want to drive a lex don’t be cheap, pay the extra 5 bucks a tank… If not there’s always civics and even better mopeds u can drive…you can ever put a ½ oil 1/3 gas mixture in those.. and this is not pointed towards VJ RC51.. hes doing his own custom stuff that I give him props for.. these are for the guys rollin a bone stock SC's and cant aford the gas

Originally Posted by vipsoarer

you guys do some research on octane ratings....its for detonation purposes only! thats why you run higher octane for high boost. the higher the octane the slower the burn cycle so you dont have detonation or non spark enduced uncontrolled fuel burn.

THIS THREAD IS FILLED WITH BAD INFORMATION! i would take all this information with a grain of salt because it definately is all hear-say. do your own research and see what the real reasons are for it. this is why some people can run 18psi and 600+ hp on 91 octane, its all about detonation deturance!