93 octane ethanol or 91 octane no ethanol
 

I found a station that has 93 octane but it has e-10. I personally think ethanol is garbage for any engine. I also have a station that sells no ethanol 91 octane, 0 ethanol gas is becoming hard to find. What say you guys on this matter? Ive been running the 91.

The Jaguar engines run perfectly on 91 octane (no ethanol) fuel. The 2 point octane increase is irrelevant and unnecessary, but the use of a fuel containing ethanol is potentially harmful (note the warning comments in your owner's manual); while a fuel containing up to 10% is permissible, it is not advisable.

Not sure which engine you have but (my) 2016 V6S engine can use up to 15% ethanol (according to the manual). You will lose some power on 91 compared to 93 (not sure how much) as the engine will not be able to generate as much compression on 91. Engine will run just fine on either. 93 not available in California (for instance) so cars need to be flexible. Different countries have different octanes. Modern cars are designed to be able to be run on different octanes. Knock detectors (premature ignition) are used by the ECU to adjust spark timing to eliminate it so they can optimize power output while preventing engine damage from knock.

There are a lot of strong opinions about ethanol. The one problem that I am confident about ethanol is it does is allow more water to be absorbed/dissolved into the fuel. Water vapor from air is more soluble in ethanol than gasoline/petroleum. If you use the fuel in your tank quickly (and is doesn't sit at the gas station too long I suppose), I doubt it causes too many problems. If you don't, then maybe it does as water will be absorbed in ethanol could create issues.

just my 2 cents.

We have 91 and get ethanol added in late fall till early spring.

I guess I don't understand why people hate on ethanol so much; it just doesn't make any sense to me. It's a common fuel that millions pump into their vehicles every day, and modern vehicles are built to use it. I certainly understand some of the water solubility issues ethanol can have, but its not a major problem with such a low concentration and unless you're letting fuel sit in your tank for a year, you won't have any issues. I just don't get the beef. To me, the performance and cost benefits greatly outweigh the negatives.

Potential for increased water absorption and a 3 to 5% decrease in fuel economy (without a similar reduction in cost per gallon) are my main beefs with EtOH in gas.

https://www.fueleconomy.gov/feg/ethanol.shtml

Dead on with the loss of thermal energy, added cost, and lost mileage.

It's also a huge pain in the ass for lawnmowers, chainsaws, and other engines that don't see everyday use. Let's not even count that instead of putting that corn in animals for food on our tables, it's going in the gas tank. Makes our food more expensive too. Just stupid all the way around.

I'm not too concerned about it in my modern cars but it's awful for older cars that were never designed to be running ethanol. It just seems to eat through components over time.
If 100% gasoline is still an option for you, I'd go with that over E10 all the time.

Ethanol-containing gasoline degrades very quickly if you let it sit. It ends 'phasing' or separating into ethanol-water mixture and lower octane gasoline. This separation can corrode fuel tank, injectors, pumps and so on even on E-10 hardened car.

On classic cars, it also swells seals and damages fuel pumps.

This is what the Quick Start Guide for my F-Type says about fuels: "If the vehicle can use E85 fuels (85% ethanol content) it will be stated on a label on the back of the fuel filler flap (NOTE: my car does not have any such note on the fuel filler cap). When using E85 fuel, 1 in 4 tanks of fuel must be non-E85 premium quality unleaded fuel. Do NOT use E85 fuels if it is not specified on a label on the back of the fuel filler cap. Equipment necessary for the use of fuels containing more that 15% ethanol is not fitted to this vehicle. If E85 fuels are used, serious engine and fuel system damage will occur."

and further:

"Avoid using fuels containing methanol. If it is unavoidable, do not use a fuel with more than 19% methanol content. The fuel must contain co-solvents and corrosion inhibitors. Fuel system damage and engine performance problems can arise when methanol is used."

What the Jaguar engineers think about ethanol and methanol seems pretty clear to me.

Corn production for ethanol is not at all a threat to livestock corn so it doesn't affect food prices that way (but biodiesel using corn biomass is more expensive than standard petroleum-cracked diesel and therefore costs trucking companies more to buy (and gets worse fuel economy) which translates into higher food prices). Just the opposite--the government has been subsidizing ethanol production since the inception by buying up surplus corn from farms everywhere. Many farms purposely grow corn just for ethanol production and many overproduce just to sell the surplus for ethanol. From an economic standpoint it is still more expensive than oil.

93 with an actual 10% ethanol content is great! Problem is that it's not always 10% so your 93 octane tune may cause knock if you aren't getting that 10% eth content

My main gripe with ethanol besides decreased efficiency and potential harm, is that our tax dollars are already paying for it. We are paying twice for it. Win/win for the government. They use our tax dollars buy the corn, pay the refineries to produce it, and then tax us on it at the pump when it's not any cheaper. We need a Boston corn party or something.

Cutting our limited amount of gasoline with corn oil means there will be a chance my grand kids will be able to enjoy the sound of a V8 someday instead of the whizz from an equally fast, but uninspiring Tesla.

The octane has no impact on compression, but will serve to cause the computer to retard the spark (reducing power) if the knock sensors detect knocking due to a lower octane fuel. As mentioned, higher ethanol concentration reduce the fuel’s heat of combustion and therefore reduce combustion pressure, along with power and fuel economy.

what he said.

go 91 no ethyl

Experiences vary greatly....which makes me wonder about the actual E10 content. The pumps say "Contains up to 10% ethanol". The implication is that at least some will have less than 10%. Maybe 3%, or 6%? And, hey, maybe some 15% brews are being surreptitiously slipped in? I dunno.

In my neck o'the woods E10 has been standard issue for decades and all my older (80s vintage) Jags have run fine with it....as do my lawnmower, leaf blower, portable generator, etc. which sit for months at a time without use. And this is the wet Pacific Northwest. I've never had unusual/premature fuel system problems using it. I mean, if a fuel pump fails at 20 years old can we really assert it would've lasted longer with non-E10?

Long term storage with E10 can be a problem, severity depending on conditions. Very dry conditions with minimal temp changes, perhaps not so bad. Wet conditions and large temp fluctuations, perhaps not so good.

If you have a modern-ish car with well sealed fuel system the E10 lasts a good long while in my experience.

I'm not "for" E10 gasoline. If it can be conveniently avoided, I would recommend doing so. At the same time I think it has become a favorite whipping post. I remember back in the 70s replacing dried out carb gaskets and accelerator pumps, leaky rotten fuel hoses, rust-filled fuel filters, and 'sunk' floats. We didn't have E10 to blame back then. We shrugged it off as old age.

Cheer
DD

your opinion of ethanol is completely wrong. You drink wine, beer, Scotch and Bourbon with ethanol. ( and probably enjoy it).
Your Jag will too. Ethanol has the following good properties for your engine.
105 octane
Cooler running
Helps dissolve carbon deposits that are typically formed on the back side of the intake valve since our EFI. System is batch fired. That is, the injectors all squirt gasoline at once and let the camshaft sort it out.
Indy 500 race cars use 100% ethanol. NASCAR uses 15% ethanol.
In drag racing if you use Ethanol you are put in a faster class than if you use gasoline.

Everyone seems to forget you need something in gas to keep it stable, would you rather they put lead back in gasoline?
Also, ethanol gas at e85 needs more fuel to ignite with the same power as e10 and it is more corrosive than gas, so the car needs expensive lines and seals and a way to detect e85. So Jag probably could not afford to make the car e85 compliant.

Just my :icon_twocents:

No ethanol for me
 

Not sure what all the versions are for ethanol in various states, but having had experience with it in Illinois and Wisconsin, I have made the decision to stay away from it. In Illinois, ethanol plants were built and studies may show costs more to produce.

https://www.forbes.com/sites/michael...h=6ee66f1d5f4e

In my personal use, ethanol in my small engine items (string trimmer, weed whacker) messed up the carbs and made them hard to start. I am making the effort to reduce my use of gasoline tools, so moving to many DeWalt battery versions of these tools, as well as their battery lawn mower. Worth the ask, how much does it cost to produce the electricity for charging the batteries, and where do the batteries end up?

I have a 69 E type that came from the factory with stellite valves and had a 2018 engine rebuild. I put only 91 ethanol free gas in him, as that is available in this area (north central WI). While I don't think my 2017 F can handle ethanol, not interested in going there, only to perhaps regret it later and after $$$$$$.