I love that guy too BTW and makes a really important point about the problem with GDI and accumulatia on of carbon.
I recently bought a Mini which is turbo GDI for 5% of its caryard sticker price, because the engines have a bad rap due to this issue.
Initially treated with GDI decoking fluid, ran it on increasing ethanol fraction (e50 works well this turbo setup), added an AEM water methanol mist via the MAP sensor and extra injector on the intake plenum, fed by the washer reservoir.
I also bought a competent diesel air oil seperator setup but with these mods doesn’t need it. Bottom line is that you can pickup SIDI (DISI / GDI) coked-up modern marvels (basically 2006+) that seem to have had their day for a bargain.
I paid $5k for what is pre-facelift of current model, spent less than a grand and a bit of TLC, log and tune, now have a reliable, clean, efficient 250 HP modern runabout.
Lack of PFI to supplement SIDI was a disaster for petrol, alcohol is the easy answer versus dealing with managing coke and sludge.
PFA detail on simultaneous (twin fuel) injection.