It will RAISE the limit from 10% max to 15%. As far as I know there are no places currently selling 15% unless it is a FlexFuel vehicle. Bob, were you driving when they introduced E10 years ago? It wreaked havoc on old vehicles as the ethanol "washed " the surfaces of the tanks and the resultant gum clogged up fuel systems. It even affected boats that had fiberglas tanks by melting the resin and causing floating bombs as the gas accumulated in the bilges. It ate up fuel line hoses, diaphragms and on aluminum tanks it caused a white "sandy" residue all around.
I've been driving, and buying gasoline, for over 50 years; thank you for asking (I got my learner's permit at 15-and-a-half, as soon as I could, so since late 1968 or early 1969). How long have you been driving?
The first appearance of 'gasahol' in California pumps that I became aware of was in a brand called Beacon, which I believe was either purchased by or morphed into Arco brand. There was a Beacon station in Menlo Park where I lived when I bought my first Healey, and it's been over 30 years but IIRC I avoided putting that fuel into my Healey (though I do recall putting it in an old Subaru I owned because it was a few cents a gallon cheaper, and don't recall having any problems in that underpowered turd).
Randy, please re-read my CAREFULLY CHOSEN words (I've emboldened the salient ones):
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FWIW, I've never had a problem with 10% gasahol in any of my cars; for yucks, I put an HD diaphragm in denatured alcohol--50% or more ethanol with other nasty stuff--and, so far, no visible deterioration."
Nowhere, in this forum or any other, have I disputed that adding an adulterant--including ethanol and possibly some of the 'miracle' fuel additives--to auto fuels can be problematic. I have a background in chemistry and am fairly familiar with the possible deleterious effects of organic solvents, and was never surprised by reports of damage caused by fuels containing a strong solvent like ethanol (or gasoline, for that matter). Between my late father's cars and mine we have a small 'fleet' of seven owner-maintained vehicles--none newer than 2008 model year--and two ancient farm tractors. My father and I never experienced a problem with any of these machines that we could definitively attribute to ethanol-laced gas* (one problem is that California does not mandate the disclosure of ethanol content in our gasoline, so one cannot be entirely sure, but most pumps state that some ethanol
may be present in the fuel). But, to my knowledge, none of our machines have fiberglass or aluminum gas tanks. David Nock believes that ethanol in gas causes our cars to run lean, causing the expected problems but, again, I have not personally experienced this (I may have enrichened my carbs during normal tuning exercises though). Ethanol is highly hygroscopic and will absorb moisture from the air; I suspect the 'white sandy' substance found in such tanks may be aluminum oxide (i.e. corrosion). Pure aluminum is highly reactive and will quickly form a thin coating of aluminum oxide as soon as it is exposed to air (anodizing is a controlled application of this principle, and any welder knows you have to carefully clean the oxide coating on aluminum in order to get a good weld).
Note also that the composition of 'gasoline' itself has changed significantly over the last few decades. I confess I don't have much knowledge of the changes made by the refiners--and they're likely proprietary secrets--but from what I've heard gasoline is less of a blend of long-chain aliphatic hydrocarbons--with a bunch of highly toxic tetraethyl lead added for detonation prevention--and now contains more aromatic hydrocarbons.
re: "It will RAISE the limit from 10% max to 15%."
I believe this statement to be misleading, if not downright false in at least one way (E15 has apparently been available for some time in some states, though its use was restricted in summer months due to its contribution to smog). I couldn't find the article I referenced earlier, but here's one, from a credible source, that addresses the
actual issue:
https://www.forbes.com/sites/ellenr...-rule-wont-change-your-gasoline/#7468ba797d96
As usual, Reid addresses this succinctly and level-headedly (although I am concerned that my 2008 Mustang has 'NO E15' printed on the gas cap). So far, though, I'm not losing any sleep over this. Also, remember what a catastophe emissions control, mainly catalytic converters, were going to be for those of us who like 'performance' cars? You can now walk down to your nearby Chevrolet, Ford or Dodge dealer and buy a car with north of 700 horsepower off the lot that gets 25MPG. Not a bad thing, right?
* I do have the common, temporarily stumbling problem when driving for the first couple miles after a hot start on a hot day, and I do suspect that may be due to fuel vaporization; which could be due to ethanol or any other component of the fuel. It does seem to be less evident on the rare occasions I can fuel with pure gas.