GDI won't ping like 3.6 for example. It can literally run on anything.
For active users ( WOT, hot weather) I would recommend premium, for normal driving (long trip, granny style) regular ok.
I personally would put the highest octane number in it just to enjoy max output. Why would I pay upfront 1K extra for advanced technology and then try to save 200$/year by using lower grade gas.
I agree, it requires " mechanically clean" gas, any microscopic impurities that are harmless to MPI system will scuff the surfaces of GDI high pressure pump cylinder which will lead to pressure drop. We just replaced 2 of those on Audi 4.0 T V8 motor at 65K, only premium TT gasoline used. No carbon issues so far. I think carbon isn't an issue on newer GDI motors, running on synthetic oils and using Atkinson cycle will postpone carbon accumulation problems closer to 100K+ mark.It won’t ping, but it will carbon up faster if you run cheap gas (especially if you don’t run a catch can). Direct injected motors don’t burn the junk recycled through the pvc.
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