E85 here in Chicago suburbs is $2.70 and 91 octane is about $3.70. 93 octane is not extremely common here either.Biggest benefit for E85 isn't fuel economy at all..but what it can do for boosted or nitrous - performance applications. E85 is about $1.57 here in Dallas and $3.14 for premium 93. You don't want to run 87 if you're boosted...too much chance for knock...less with 93 and even less with E85.
I dont plan on running an aftermarket standalone until the stock ecu isn't able to pull enough fuel at idle and running around town- it handles the 440cc injectors just fine on 93 and E85. Anything bigger it would struggle and run too rich...what others have seen when running MRW larger injectors. Until I max out these 440s injectors, I'll stick with the stock ecu and should be just fine.
I'm personally gonna run on 93 when supercharged. It's also challenging running E85 when in winter here in Illinois.
Keep working on your RAV4.We need all the input we can get,since not many people modify these 2GR-FE engines. Heck,I think it's only a handful of tuners for these out there.