U.S. corn-based ethanol worse for the climate than gasoline, study finds

> That's straight up not true if we define "run" as "run as well as on E10" (granted I wish it was so I could save money on having to upgrade fueling for my cars).

Variances between vehicles will always be a factor. This doesn't mean that most of them won't run sufficiently or even well with a higher ethanol ratio. Your experience with your 4 Series is interesting, and you seem to know a lot about ICEs, but all the research I conducted before I even considered trying E20 convinced me that the possibility of engine failure or damage is extremely remote.

I'll have to find them when I get home, but there were at least 2 studies I came across where researchers tested (I think) E20 on several vehicles from different years and manufacturers to see what would happen. The only issues the vehicles encountered were ones that had nothing to do with the fuel system.

In any case, it is a nuanced topic, though I struggle to say it's quite as complicated as your perspective.

> Even with a tune, E20 is the maximum the fueling system can maintain without straight up running out of fueling and going into limp mode under heavy load

That's very interesting. With my vehicle, it ran almost identically to E10 on E50 (yes I made sure that was roughly the ratio present in the tank), and on E60 it started to run rough and showed a lean condition code but was still perfectly driveable.

> Ethanol can be better for sure, my car is a million times more enjoyable on a simple E20 blend than California's awful 91 blend, but at the end of the day, ethanol fuel is a bit of a farce (and again, I'm someone who'd have a terrible day if we actually stopped producing it).

In any case, I find it an amazing fuel. Although my vehicle isn't optimized for the higher octane rating of ethanol, I experienced an obvious performance improvement on even E20 in terms of power. My bias was low in that case because at the time I was certain I wouldn't see greater power.

> Ironically the people who I personally see benefit most from E85 are people who are well off enough to use it for a performance boost, or businesses taking advantage of how much artificially cheaper E85 is. Average people get the short end of the stick and few to none of the benefits.

Do you think that's a limitation based on the availability of Flex Fuel vehicles, or the price of the fuel itself? Even when adjusting for the energy-per-volume using the most pessimistic calculation, E85 shouldn't be more expensive than gasoline. At current prices, E85 should be ~$0.50 less per gallon than regular gas when adjusted. At least that's how it is for the fuel prices near me.

But let's say that E85 and gasoline cost exactly the same per joule. All that would mean is that E85 has less range. If EVs have taught us anything, it's that many people don't mind having less range.

Do you really think they would have put those “flex fuel” badges on cars if they all could run E85 without problems?

From my interwebs knowledge you need a fuel sensor (to tell the percentage of ethanol) and an ECU that can take advantage of the different fuel blendings.

So, yeah, maybe not a dead car but definitely not an efficient one.

That's such a small difference it could literally just be that it's a slightly richer setting because E85 needs a higher fuel ratio for Stoichiometric burning.

That is not a small difference, and you can't get 30lb/ft by "richening things up"

One other big, basic reason from early school Biology you are missing is the Nitrogen Cycle. Earth crops are not particularly efficient at fixating Carbon into biomass and generally need plenty of other mineral inputs such as potassium and phosphorous and zinc and especially Nitrogen. Nitrogen alone is an interesting problematic "inefficiency" because Nitrogen wants to be a gas at Earth pressures/temperatures (like Carbon) and so also needs to be fixated and plants very rarely have evolved that sort of fixation directly, instead relying on "the Nitrogen Cycle" to (eventually) fixate it into soils.

One of the things humanity has done as it has industrialized agriculture (to deal with the time issue of that "eventually") is that it has industrialized "the Nitrogen Cycle" as much as it can, and in so doing added a lot of additional Carbon inefficiencies to how we fixate Nitrogen for use by our crops. Modern crops couldn't grow at the same industrial scales without modern fertilizers, but modern fertilizers generally don't exist without massive carbon subsidies.

https://en.wikipedia.org/wiki/Nitrogen_cycle