Is this OK? Or should I be searching for pure gas for my Prius? Just in the last week Raceway and Murphy have switched and these were my main sources. Best gas recommendations please!
You may not have a choice. In many States, it's the law, usually during winter months to reduce ground-level pollution in the colder, denser air.
E10 is fine, and probably better for the environment than the alternative octane-raising chemicals that are in pure gas. When I lived in ND I went out of my way if necessary to find E10. The owner's manual says that E10 is fine.
While it's true there is a little less energy in E10 (my calculations show it's 96.6% as much as "pure" gasoline), I doubt you'd see the difference. It's buried in the "noise" of normal variations. It does burn more cleanly. I've used it for over 10 years now and I've noticed the engines in my cars (four different ones so far) have much cleaner intake tracts than when they are run on "ordinary" gasoline. Some will tell you E10 will break down quicker. I've used it in my RX-7, and for 7 years I stored that car with a full tank of E10 "premium" fuel for 6 months every winter, with no problems. When I sold it last summer the fuel injectors were still functioning perfectly (the car had an aftermarket ECU that read out how they were performing). I think a lot of the resistance to E10 is from the same mindset as the resistance to hybrids.
