Free advice from a VW 1.8t owner (Still shopping for my first audi) (which is the same powerplant as your car) - use low test gas with this engine and the only down side is you make less power. Cheap gas causes knocking and the 1.8t ECU is great at reacting by (I think) retarding spark, and it may also allow for less boost. The ECU did this seamlessly in my Jetta and in also my sisters 04 passat.
Can you feel the loss of power when you use cheap gas? Yes. A lot? Well, no not a lot but yes its pretty noticeable.
Can you feel any other negative? No. The ECU and knocksensors work as advertised.
I would estimate more than 3 hp loss; my seat-of-the-pants dynamometer suggests 15 hp difference from 87 octane to 91 with that 150 hp 1.8t.
You have nothing to lose so tank up with 87 and see what happens. You might be OK with how it feels.
Can you feel the loss of power when you use cheap gas? Yes. A lot? Well, no not a lot but yes its pretty noticeable.
Can you feel any other negative? No. The ECU and knocksensors work as advertised.
I would estimate more than 3 hp loss; my seat-of-the-pants dynamometer suggests 15 hp difference from 87 octane to 91 with that 150 hp 1.8t.
You have nothing to lose so tank up with 87 and see what happens. You might be OK with how it feels.
