I won't worry about the brand - like everyone here said - they are all very similar. But I do worry about where you are buying the gasoline. Buy from a gas station that is busy and has a quick turn-over of their stock. Stale gas sitting in the underground tank for a long long time is what is bad.
One could hang out at the local dog parks and offer to collect the dog-doo so the owners don't have to. Could get a lot of it that way if you pulled an 8-hour shift doing that.
That's what I do. About 95% of the time I fill up, I'm using the same station and most of the time the same pump.
This is true only for tankfuls. That is why you have a display. All you need to check for is temp wind, etc that are obvious variables, and test with car warm. Gas varies far more than the other variables. Just read your mpg meter! Forget looking at tank averages. Don't bother. The important thing is the instant readout, at a known place and speed, and the average over a short 15 to 30 mile test loop under conditions you can easily repeat. For me Shell works best every time. Exxon and Mobil are close enough I can't say they are worse. But I've had other brands that cut my mpg by over 8 mpg. This is very visible just driving at a constant speed on level road, on a day there is no wind. Temp variations you can calculate or use Wayne's palm device to compensate for. You can use that to correct for wind too if it is steady and from a known direction. Easier to pick days where temps match and wind is negligible. The instand readout is especially useful if you can use your nav or something to know when road is level. Bad gas for me was reading under 50 mpg at 55 mph no matter what I did! Good gas at that speed is virtually always up toward 60 or more, unless really cold outside.
Frank: Oops sorry to hear that. I'm sure missus is looking after you. I wasn't goofing off today too much. I always bring along my personal notebook computer, which has a Rogers Wireless internet card in it. The tower is on the next building, so I can usually expect DSL speeds. jay
Out of alturistic feelings and perhaps too many wine samples from the couple down the hall, I hearby offer all my cat's used litter. Feel free to pick it up anytime. Please.
I have read somewhere that Toyota recommends the usage of top tier gasoline products in their autos. According to what I read they consider Conoco and Shell to be the ones to use. Today I filled up at a Conoco station in Northern Minnesota and noticed the same statement posted above their pumps. They also included the Honda brand Months ago I decided to test out this idea on a set route for 100 miles each fillup. I am a Courier so putting on 100 miles easy and I do a defined route each day. I drive at least 250 to 300 + miles each day. so fillups come quick. I can attest to the fact that using Shell and Conoco will improve your mileage slightly. I realized a improvement of 3 to 6 miles mpg. As a futher test I filled up using Super America gas one day, my mpg dropped 4 mpgs the next day( after driving 325 miles) i filled up at Conoco using their 90 OCTANE FUEL MY MILEAGE JUMPED BACK UP TO THE PREVIOUS TOP TEIR GAS LEVELS. I own both a 2002 and a 2005 Prius and have noticed a difference in both cars using top teir gas. The 2005 is still being broken in at 8000 miles, the 2002 has 60,000 miles on it. Tom
Frank: I meant used poopy cat litter, not the actual cat. You can pry BooBoo out of my cold dead fingers. jay
Top Tier gasoline website http://www.toptiergas.com/retailers.html If this is true it's just one more reason not to buy from those Exxon-Mobil b@stards.