ime not sure what a good way to tell if the premium gas you are buying is really premium gas other than getting a knock sensor. Is this the case??? And if so, can anyone tell me what would be a good one to get is?? Thanx RRR

 

No.

The EVO already comes with a knock sensor.

 

There is no hard fast rules with gas stations, you never really know ahead of time if a particular station has a contaminated tank or if a delivery person accidentally filled the tank with the wrong type. I usually find I have better luck in the larger high traffic area stations, where they seem to maintain there systems better. When I have gotten some bad gas, it was usually some small out of the way station.
I am sort of partial to Chevron, then Mobil, beyond that it's what ever I can find. Most are pretty similiar and there doesnt seem to be a huge/noticeable difference.