As I continue to build my car in pursuit of "The Quickest Road Going GR Corolla in North America", I'd love to share with you all my learned lessons and interesting takeaways. If this is cringe, I'll stop, I don't want to annoy you all, but if it helps someone answer some questions they may be tossing around in their heads, even if it's just ONE other person, I think that'd be amazing.

Initial Cost:

Winner: 93

$0 is pretty hard to beat, LOL!

Loser: E85

Expect to spend at least $2000 getting to where your car can utilize and take advantage of E85 or even an E85 blend such as E40-E70. If you're a nutter like me and you go whole hog, you'll need a flex-fuel sensor but the upshot is that the stock fueling system seems to be up to the task. I'm still running the stock fueling system. That said, I think higher flow injectors and a higher flow pump is definitely a good idea. After some testing and seeing where the tuning limit is at this point, I may just make a fuel-system upgrade part of my "Phase 2". I'll have to research more on that, however.

Fuel Economy:

Winner: 93

But not by as much as you think. Around town, 93 really shines here. Even with my heavy foot, I can get anywhere from 20~23mpg. I live in suburbia with a LOT of roundabouts and traffic lights so YMMV (literally). This is amplified in the winter time where E85 and E-Blends tend to fall on their face. On the highway it's actually pretty comparable. On my recent road trip, while using 93, I averaged between 25.1 and 26.7 MPG.

Loser: E85

But not by as much as you think, LOL! Around town I average 19.1 to 20.4 MPG. On that same road trip as above (on the way back) I averaged 24.1 to 25.5 MPG. Around town is worse due to stop and go and speed-up/slow-down style driving. The difference between E85 and 93 closes up a lot when you're able to set the cruise control and just drive at a relatively constant speed for long distances.

Cost at the Pump:

Winner: E85

Here in Fishers, IN, E85 is (at the time of writing) $3.35-$3.45 per gallon. Factoring in the economic losses and you're still doing pretty damn good per tank, especially if the majority of your driving is highway or long stretches without speed-up/slow-down driving.

Loser: 93

At the time of writing, 93 here in Fishers is between $4.60 and $4.80 per gallon. It almost doesn't make sense to get 93 if you're looking to save money on fill ups.

Reliability:

Draw (with a slight edge to 93)

I haven't had any issues since switching to corn juice. I started off with an E40 blend, then gradually worked my way up with Boosted Performance and Limit+1 on speed dial just in case something went awry.

In the winter time, 93 is the winner but only at cold starts. Cold starts are . . . . stumbly . . . with E-blends. Especially here in Indiana where our winters range from pretty cold to air-hurts-your-face cold. On days face-hurting days (say below 12F/-11C), E-Blends really struggle. Something something vaporization temperature, something something vapor pressure, something something rough starts in cold. It goes without saying, if you live in a place where it drops below 0F, do NOT run E-blends or E85 during those days. I haven't experienced it, but I've heard anecdotes of E85 turning to gel. Is it true? I don't know, but I would rather just remap back to 93 if it's gonna be that cold. My car is parked in a finished 3-car garage year-round so I don't worry too much about it.

Drivability:

Winner: 93

But only just. 93 is what these cars were built for so drivability is just a matter of hopping in your car and setting off.

Loser: E85

But only just. If it's cold, you're gonna wanna idle for a bit. Not a super long time (you don't have to idle for a half hour or anything crazy), but just enough to where your exhaust warms the tank enough to get things all loosey goosey.

You'll also notice that, until you reach OP-Temp, your car may feel like it's not running at full power. This may just be something I notice and it's now intentional as my car is programmed to not allow "full beans mode" until it's warmed up fully. But even prior to that, I noticed that until my car was running at full temp, it felt like trying to get up to speed quickly took a bit more effort.

Power:

This is the fun one, right? Why we all switch to Corn Juice.

Winner: E85

BY A LANDSLIDE!

Even with an E40 blend, the power difference is tremendous. If you're wanting 300, 320, 330, or even 350+ WHEEL horsepower with basic bolt-ons and a tune, you pretty much have to do this.

You're going to be between 30 and 70 WHEEL HORSEPOWER up depending on tune and E-blend. Again this is at the WHEELS. Drivetrain loss with stock driveline components is approximately 11.11%, so you can "QUIK MAFFS" what your BHP is at those numbers.

Loser: 93

In a "stage 1" map and Eventuri intake, 93 is down by 20awhp over E40. . .  yes . . . E40 . . . not E50, or 70, or 85 . . . 40! It's not even a competition.

^("Oooookay, Dave. Why did I just read all of this?")

Honestly, and like I said at the start, I am hoping that even if it doesn't mean anything to you specifically, that someone (at least ONE person) finds this information dump useful.

I'd stick with 93 if:

• You're not interested in the rather hefty upfront cost of fuel system upgrades and tuning.
• On that note, stick with 93 if you don't have the patience to deal with the foibles that come with E85 tuning. The occasional harsh start, the fact that you're GOING to have to rolling-map your car and during that rolling map, you're going to have performance issues and you might even get a CEL or three.
• You live in a 3 or 4 season area, especially if you park outside. The winter time might render your car undrivable when parked overnight.

I'd invest in an E-Blend or E85 tune if:

• You live in a warmer state and don't have to worry about winter
• Your primary goal is power output
• You don't mind the drawbacks of fuel economy
• You genuinely enjoy the nerdiness of per-RPM-tuning for maximum gain and don't mind stumbling for a few days/weeks while you and your car get used to the new fuel.