Any oil spilled on the exhaust will smell, and some odor often gets past the hood seal at the top of the firewall at the back of the engine compartment into the heater intake. Mobil 1 when it is burning is even stronger than most others. It is nearly impossible to change the oil filter without spilling some on the exhaust, especially on a V6.
Ray McNary (RIP)suggested wraping the pipe below the oil filter with aluminum foil to keep oil of the pipe and then removing the foil and throwing it away.
I prefer to clean the area immediately after with degreaser.
