Hello, i just bought half a tank from this cheap gas station it was 76.6 for 92 octane, which was better then esso that had 91 octane for 79.9. (cdn cents per liter) i started my car today and went to chip away some ice and snow and the exhaust reeks of sulfer. i know its sulfer in the gas, can this damage my engine is anyway and/or really, really affect the mileage. so far it hasnt been too bad. thx. p.s. i thought all gas stations basically had the same gas? anyone wanna comment on this?