[MIGISMALLS]

I was wondering if it was recommended to flip the FUEL SWITCH form PREMIUM to REGULAR with no problem if I put 89 octane while on the Regular mode? will that affect the car in any negative way? or will it be ok? thanx for any help/advice i can get.

[ethangsmith]

Switching the selector to Premium will make the computer add a little more timing and boost. On 89 octane, this may result in pinging and detonation, especially under heavier boost. I don't know if I would attempt driving on 89 in Premium mode. Maybe try it, and if you hear any ping at all, switch back to regular.

[NavySVO]

ethan, I think he was asking if he could go FROM premium to regular and run 89 octane.

Sure, you can do that. Just keep your foot out of it (have some control). 9 psi with 89 octane is on the cusp of detonation, but it all hinges on the fuel you get. Just because it says 89 on the pump, doesn't always mean it is a good grade of petrol.

[MIGISMALLS]

Originally Posted by NavySVO

ethan, I think he was asking if he could go FROM premium to regular and run 89 octane.

Sure, you can do that. Just keep your foot out of it (have some control). 9 psi with 89 octane is on the cusp of detonation, but it all hinges on the fuel you get. Just because it says 89 on the pump, doesn't always mean it is a good grade of petrol.

yeah this is what i meant. well so far im running 89 octane and running on Regular mode right now and all seems to be ok so far. i dont really step on it or take off for the same reason that i dont want to boost much. i know on the regular mode the comp only allows 9psi but i dont wanna try it n see if itll still boost what i regularly do.

Thanx for the info.

[NavySVO]

you could always run a hose from the compressor scroll outlet port straight to the wastegate actuator. That would garrantee 10 psi of boost, as the spring in the actuator is rated at 10 psi. As long as the spring is in good condition, you should be good.

[MIGISMALLS]

thanks for the info guys.