We run Reg. octane in our Volvo (and in the TSX when we had it). The dealers don't even fill their own loaners, or the cars upon delivery with Premium. We spoke with 3 techs at 2 different Volvo dealerships and they said no noticeable performance decrease would be apparent, and it wouldn't hurt the engine either. I've used all three grades, and I never feel enough difference to pay the premium for premium.Just my opinion, I'm not sure how it effects the TL.
