i found a gas station 6 miles from my house that uses pure ethanol free gas! Heres the problem they only have up to 90 Octane......


So what do you guys think is better 90 PURE or 93 with 1/10 ETHANOL??

tell me what you would do.

oh and the pure is 2 cents cheaper per gallon than the cheapest premium ive seen.

 

I am nuts about following the manufacturer's guidlines for gasoline.... but I'd go with 100% gas, even at 90 octane if I could find it.


(Wait a minute, do our cars need 91 or 93 octane....? Three points low is pretty low)

 

If it really is ethanol-free, the 90-octane is definitely a much better deal, since you should get both marginally better mileage and it's cheaper.

Many people in various states (like mine) can only get 91 octane gas at many stations and it doesn't seem to knock or cause the ECU to back off, so I think you'll be fine on 90.

On the other hand, the ethanol is almost certainly not hurting anything besides a marginal hit to your mileage as long as it's quality - cars built in the last 20 years were designed with E10 gas in mind and have E10-resistant hoses/pumps/injectors/seals. The risk with E10 gas (and why it still gets a bad rep) is that it becomes unstable and picks up water over time, so a station that doesn't get filled frequently or has poorly sealed tanks will deliver bad gas that can cause damage.

The chances of breaking a modern engine with an intelligent ECU via gas that's one octane number lower than usual are slim to negative, especially an N/A car. Knock detection and compensation has gotten quite good. If you notice a loss of power, just don't use that gas again!

 

I always buy from stations that move a lot of gas, so my only concern is what I put in bold.

Can anyone else "in the know" back bri3d up here? I still worry about the effect of E10 on cars that sit a lot (like you poor guys up north or my Red one which is being driven about 100 miles a month now, waiting for a buyer!)

 

Letting it sit in your tank will probably cause it to seperate and/or pick up water as well - fuel stabilizers are supposed to prevent this, but I have no idea how well they actually work. I drive all of my cars at least once a week even when it's snowing (and pretty much every day otherwise) so I've never worried enough to do extensive research into it.

 

If you go that way, I'd get some octane boost.

A few years back I put mid-grade 89 in my Buick.

A week of that and I spent $400 on a harmonic balancer.

Ethanol is widely used in Europe as here. Our engines are designed for it. I agree with Bri3d and would probably use an additive if the car sits.

At least ethanol is not a carcinogen if it gets into local groundwater, unlike MTBE

 

I would be totally surprised if this were true. No wholesalers around here have it available anymore. I don't know why your area would be any different. Check it out to be sure. It will work either way. These are pretty smart cars. The ECU will adjust timing. Most octane boosters will cost around 4 bucks and treat up to 25 gal, so it really won't save you money.

 

its legit im sure of it and the reason i would think i would have it and not you is because i live in heavily populated south florida where exotic sports cars are somewhat the norm... No offence but how often do you see lambo's , rolls, ferrari bentley etc in Indiana? around here every week

 

Bri3d is correct. As far as storing your car for long periods, you should put a stabilizer in it and it should be fine as well. BTW, I've been in the fuels business (regulatory, policy and consulting as well as in the refining side of business for over 20 years)

 

The owner's manual calls for 91, but I'd be stunned if using 90 would make any difference whatsoever. Besides, it's my understanding the rating on the pump is a "minimum" rating....it may actually be higher.

ETOH only has about 65% of the energy as pure, so a 10% blend has about 96.5% as much energy as pure...no matter what the octane rating is......93 pure has no more energy in a gallon than 87 pure would have.

Driven identically....the pure should get you almost 1 more mpg in an XF.

 

I have access to alcohol-free gas in the city where I live but discovered that while I get better gas mileage with it, the car has more power with the
92 octane BP gas. It is a noticeable difference.

 

Hi,
We europeans got 95 and 98 as std. Sometimes we get up to 100 octane when it's a promo at shell. Should there be a difference in performance between 90 and 100?

 

I talked to a guy at shell a couple days back who is an expert in fuel and he said that 100 Octane fuel helps "clean" the engine (i.e valves etc.). But there is no difference in performance according to him and a test I read in "Auto-Motor und Sport", the German car magazine.

 

I remember Shell doing the promo with 100 octane. Ferrari power or whatever they promote.. I think the higher the octane level the quicker the car. simple as that. haha
I do not have a clue but it would be nice if that was the case. Especially as our fellow members in the state are paying the gas at a 50% discount minimum compared to us.

 

I honestly dont think that its quicker. I sometimes put V-Power 100 in the Jag. XJR and I notice 0 difference.....

I just cant wait to ship my Crossfire over here to fuel with the good juice

But I will do everything in my power to avoid having to fuel it E10 fuel.....

 

I live in Hamiton County. I see them everyday. We have some gas stations that are located near the race tracks that have separate pumps for "leaded" gasoline, but none are alcohol free around here anymore. The distributors just don't have it. The industry as a whole has changed. Jet Star is a company that hauls gasoline, and jet fuel. They have a lot military contracts, and move most of the jet fuel used in Florida today. They haul gasoline when not moving jet fuel. You may have a station carrying a "leaded" fuel, but I wouldn't worry about it, whether you are right or wrong, but don't use a "leaded" fuel.

 

What is the octane rating of the ETOH-free gas you're talking about & what is the % ETOH of the BP 92 you're talking about?

If you're talking about 92 vs 87....then of course the ecu is changing the timing or something to prevent knock with the low octane pure.

 

Just remember European ratings are in RON, unlike here in the US.

 

Anti-Knock Index (AKI)

In most countries, including Australia and all of those in Europe, the "headline" octane rating shown on the pump is the RON, but in Canada, the United States and some other countries, like Brazil, the headline number is the average of the RON and the MON, called the Anti-Knock Index (AKI, and often written on pumps as (R+M)/2). It may also sometimes be called the Road Octane Number (RdON) or Pump Octane Number (PON).
[edit] Difference between RON and AKI

Because of the 8 to 10 point difference noted above, the octane rating shown in the United States is 4 to 5 points lower than the rating shown elsewhere in the world for the same fuel. See the table in the following section for a comparison.

So the exact same "pure" BP 92 (no etoh) that I use in KCK.....would be listed in Europe as 97. BP also has a 91 & a 92 that has etoh in it....you have to ask the owner of the station to be sure.

 

In addition:

It was true up until the advent of advanced ECUs that higher octane gas alone wouldn't get you better performance - just that lower octane gas would damage your engine.

Most of today's cars, though, have knock sensors that allow the ECU to scale back performance for lower octane gas will still performing better on high octane gas. Most N/A cars are designed for the highest readily available octane of gas but won't completely break if a lower octane is put in (I would NEVER recommend doing this, though, at best your car will run like a dog).

Things get more interesting with forced-induction cars, though. Many FI cars these days are able to cope with higher boost than is possible with premium gas (due to preignition), and are tuned to allow this from the factory. Thanks to computer-controlled wastegates and supercharger clutches, they're now able to run scaled back on 91/93 octane but keep the ability to run higher boost if the gas allows. So many factory-stock F/I cars will automatically increase pressure if 100/103 octane gas is put in, sometimes leading to damn impressive results. Similar results are seen with E85 - if the fuel system on an FI car is able to handle E85 (which is 105+ octane as pure ETOH is 127-129 octane in the American system) the car can be tuned to handle incredible amounts of boost.