1.8GDI, 91 or 96?

[marmel31]

I have a 98 1.8GDI at the moment while I'm waiting for my VR-4 to get here from Japan. I have been putting 91 into it and it seems to run fine but I was at the local Mitsubishi dealer the other day and the owner told me I should be running it on 96 and using the additive you can buy in the syringe. He said if I use 91 the GDI motors are prone to carbon build-up in the cylinders. Any thought on this??

[Kieran]

That's right. THe GDI needs hi octane fuel to operate efficiently. It runs so lean that it relies on the high octane content to stop pre-ignition. If you use low octane petrol, the GDi system will compensate by retarding ignition and using a bigger injector pulse... reducing both power and mpg.

[marmel31]

Thanks for your help :chugchug:

[maori_by_nature]

bro i cant afford 96 @ the moment about the only time i'd put it in now is 2 keep up with kiwi TT and kenneth again not that i could do the 2 well in the welsford run my advise if u got a warrent who cares cause they fix it 4 next 2 nuth'n if u dont do wat eva the dealer says... cause thats wat i'm doin...