Originally Posted by JamesWilson2
There is so much variation even station-to-station. One petroleum engineer put it to me, go to the station that is the busiest/most popular...the in-ground tanks are very prone to water contamination, and the stations that don't refill as often are the worst offenders. This worries me with 93-octane fuels in the Houston area, as it may sit for a very long time. I try to use Shell V-Power 93 only, and have found a few specific stations that are the least problematic. When racing the car, however, buying Shell URT100 or URT105 in a 5-gallon pail has been the safest bet, and the car runs great with that fuel in the tank.
YMMV. Great data points from you though. I would like to see the same thing from different stations (within the same brand), and possibly from different distribution companies (outlying towns, etc.) to see if there is a difference.
You don't have to worry about water much anymore. Ethanol is hydroscopic, so any condensate will be absorbed and burned in all the cars long before it builds up to dangerous levels. You have to worry about it more at places that don't use E10.