Crossed Flags Fan

Hope your kidding because....:The high octane ratings are the allure of avgas— and some people have tried it as a substitute for racing gas, but it's not really a great idea. High octane is good in that it helps stop premature detonation (knock) but avgas is less dense, requires different carb or injector jettings, and is generally designed for very different environments than, say, racing gas.

http://www.fuelexpert.co.za/canirunavgas.php

PobreWey

I run Shell 91 premium octane with no ethanol . There is 94 octane gas right beside the Shell but I stay away from ethanol.

Motors5

That is true and you can run any engine in Europe on 95 octane = 91 US. Ferrari or Porsche, it does not matter but it is not recomended to go below this unless you have no option. There are very small differences and nothing you notice during normal driving in the Vette.

Skid Row Joe

Filled up only with 87 unleaded at Murphy Oil Co. Didn't notice whether it had ethanol in it. My diesel engine vehicles get a percentage of ethanol in the fuel.

LDB

The first significant ethanol use was in the 1970’s in high altitude states like Colorado in winter, when they had air pollution from carbon monoxide due to the combination of high altitude and all the wood burning fireplaces. Ethanol did reduce emission in cars with carburetors because carburetors meter fuel volumetrically with no feedback loop, so the lower energy content of ethanol made those cars run leaner. But it didn’t catch on in a really big way during those years because MTBE had similar effects and was cheaper. Once fuel injection with O2 sensor feedback became the norm in the early 1990’s, the emissions reduction benefit of ethanol (and all other oxygenates too for that matter) disappeared.

When MTBE started being phased out about 2000, ethanol should have gone away too. Neither had any emissions benefit any more. But the farm lobby was successful in getting it falsely declared to be a greenhouse gas reducer, and that’s when usage really took off.

LDB

Ethanol is too light, with too high an ignition temperature for diesel, and is not used that way. You are probably referring to biodiesel, which is made from reacting vegetable oil or animal fats with an alcohol (usually methanol, but sometimes ethanol or propanol) to make esters.

Note: See post #36. Turns out there is some ethanol being blended into diesel these days, so I was incorrect in saying ethanol is not used that way. As detailed in post #36 it’s way way dumber than ethanol in gas, but it is now starting to happen. LDB

Always Red Dave

Patman

No matter what fuel I run, it will always be Top Tier. I don't plan on ever adding any additives to it as well, there should be no need with me using TT fuel from day one.

Corgidog1

Shell 93 octane

dvilin

93 Octane, no particular brand, sometimes Sunoco but always 93.

MikeyTX

About the only way you'd ever see a difference would be on a dyno print out. And as mentioned, minimal. I'd run what saves me money at the pump while providing what the car needs.

dbaker

We have mostly 93 w/10% ethanol here in the South.

One time(they were out of 93) I did run some 89 pure gas and it ran just fine on the street.I would not make a habit of it.

\db2

Skid Row Joe

No, it's right on the fuel pumps:
"This product may contain up to 10% or 15% Ethanol."

MikeyTX

Are you looking at the pumps that dispense both gas and diesel ? Such as at QT or RaceTrac ? The ethanol sticker pertains to the gasoline. Who ever places those on the pumps simply slaps them on there. That is for sure. Also, I've watched people move the stickers. When the weather is warm, that adhesive is soft.

Richard Ames

Highest octane Top Tier available but no ethanol fuel if very low miles as it causes a varnish build up if in a low fuel usage situation (months to use).

LDB

I’ll be darned. Things have changed in the 8 years since I retired. When I saw your post about ethanol in diesel, I just assumed it was a mistake without looking it up. At least with gas, if you get past the economic stupidity and some easy to fix issues, ethanol is a high quality fuel as measured by octane rating about 108. But with diesel, you have the same economic stupidity, some additional issues that are more difficult to fix, and worst of all, it is a horrible quality fuel as measured by cetane rating around 5. Cetane rating is the diesel equivalent of gasoline octane, and good quality diesel is about 40 cetane. Ethanol in diesel is so lousy in cetane rating that you need a heavy dose of ignition improver to make it work.

Anyway, once I actually looked it up, I see that modest quantities of diesel are starting to be sold with ethanol. I tell people on ethanol in gas, other than the economic stupidity, the other issues have been solved, so there’s no reason to go to extreme measures to avoid it. But given how fundamentally horrible ethanol is as a diesel fuel, if I owned a diesel, I’d sure go to strong measures to avoid feeding 5 cetane ethanol to my vehicle. They may have dosed it up with enough additives to get by, but good grief, are you kidding me? Why? All that said, thanks for pointing it out, and it will teach me not to flap my jaw without doing homework, particularly on a topic where a strong lobby is in play to disrupt logical behavior.

MikeyTX

Wonder if it is auto only ? It isn't on the fuel pumps at the truck stops I fuel at.

LDB

That’s possible. I didn’t find anything in my 10 minute internet search about how much was being produced. I just found articles saying that some was being made and that quite a few extra additives were required to make it work. I’d take a fearless guess that at least until there’s more experience with it, a truck stop trying to pass the stuff off on big rig truckers would be a pretty lonely place. But having been burned once already, I’ll admit in advance that I don’t know whether any is going into big rigs. I’m simply amazed by the stupidity of it. As noted in post #36, ethanol in gas at least has the advantage that if you address various minor issues, gas engines are perfectly happy to burn it. But diesels aren’t. You’re not only having to address the minor issues, you’re having to overcome the major stupidity that combustion characteristics are fundamentally unsuited to a diesel engine.

rrsperry

Man you all overthink this.

Use the highest octane gas that is listed in the manual. I used to be in the oil distribution business, (terminal manager for an oil company), and you all thinking that Top Tier is a magic bullet, makes me laugh... In the US... GAS is gas. It's a fungible commodity. It comes from refineries by ship, barge, or pipe line. It comes in 2 flavors, 93 and 89. (depending on where in the country you are, I'm talking East Coast) I don't care who's name is on the pump, the gas is all the same. The pipeline might deliver 20,000 bbls (1 bbl is 42 US gal) of premium to us, and the next slug is 20,000 bbls to Exxon... It's the same gas. We were top tier, and loaded gas for lots of stations. (Costco, Exxon, Jiffy Mart Scheetz...) The gas is the same. Hell the additive was the same...

The only thing different about anybody's gas is the additive packages injected into the tanker as it loads for delivery. Top tier uses a slightly better additive package. (note, all gas sold must meet the minimum EPA additive package.)

Anyway, If you ask me, I'll tell you to buy the highest octane that your manual calls for, (or your engine tuner specifies). Using a higher octane gas than called for is a waste of money. If the ECU isn't detecting knock, and pulling timing, more octane isn't doing anything.

So, in conclusion... lol I buy gas at any large volume place, and don't worry about it at all.

I can't even tell you the last time I even gave more than a passing glance at what the price was. It's just not worth the effort to go out of my way to maybe save $0.50 on a tank of gas, when I'm going to play a $80 golf course and smoke a couple of $10 cigars...

Priorities...

Foosh

With regard to ethanol in diesel, I only refuel at Pilot/Flying J at the high volume truck pumps, since I'm pumping over 100 gallons at a time. I've never seen ethanol notices posted on the diesel pumps.