[metalarm]

Hi all.
I have an i30 1.4t dct  bought in 2018.
Recently, everytime I want to pick up speed or 'activate' the turbo, it drops gear, i.e. gear 7 to 5, then it starts juddering, sort of engine braking. I went to komoco, left the car there the whole day. The mechanics said nothing was wrong, its 100% in working condition. But the juddering is getting worse. But I notice if I use premium petrol, 98 or abv, the juddering becomes minimal. But if I use 95, this problem happens all the time I drive.
Interestingly, my wife doesn't experience much of this when she drives. Lol

[Greyhound]

I wonder if you are loosing traction when suddenly applying power and triggering traction control. That would exhibit juddering symptoms but you should see a dashboard lamp lit when that happens.