Fuel Octane

There was a write up from 20 odd years back here, but I'm asking a more specific question. (sort of)
It seems the book (converted to us) would say 91 octane gasoline. Back in the day these cars were made, I don't think any ethanol was used in any grade.

Local options near my house are 91 oct premium (10% ethanol) or 89 octane ethanol free.. what would you use? Better to get rid of the ethanol, or stay 91 or above?

I'm pretty sure there are some stations with 93 octane premium (10%) fuel around, maybe Shell? I'd have to look. Is it worth seeking those out only? I've maybe seen 95 once, can't really remember where at this point so and that would be decidedly hard to stay with. I know I've seen ethanol free premium (91) somewhere too but it would take some searching and again be pretty inconvenient to source every time.

So hopefully 91 (10%) or 89 (E free) will do. I really am not concerned so much about cost, as much as I want to be good to my 328.

 

You want 89 or better, no ethanol. Not inconvenient or hard to find, though - there's been a web site for many years, Pure-gas.org - ethanol-free gasoline in the U.S. and Canada , that lists all stations offering ethanol free gasoline. They currently list 638 stations in South Carolina!

 

89 oct ethanol free is 1 mile from my house, and not even listed on that site. If I really need 91 or better, its harder to find, only one listed on that site even.

BTW thanks for the site, bookmarked

 

FWIW, I've born running standard (10%) ethanol gas in my 328 since I bought it in '08. I have never looked for non-ethanol gas. I buy 91 (US) octane or higher if 91 is not available. Never had any issue whatsoever with the ethanol in the gas. When storing the car for extended periods (months) I add StaBil to the gas. I have had the car stored for as long as 7 months (with StaBIl) and when starting for the first time, it starts as if it was running yesterday.

 

What is the spec for a 328? For my 308 QV the manual says 91 RON which is 87 AKI (USA). That's Regular in the US which is what I run in my car. No problems. E10 or E0 makes no difference unless you worry about ethanol damage. But E10 is all we have in CT since 2006.

 

Per the owners manual, RON 95 (US 91) is specified for the US 328.

 

...and "SP95" which is RON95 is specified for the "Euro" 328, although they run also without problem on "SP98" which is RON98 (close to the US AKI91, which is RON97 I believe (?)

Rgds

 

Then to answer the OP's question, your better off with 91 E10.

 

There is an interesting video on Youtube where they took a basic V8 engine and dynoed it using 87 to 116 octane fuel.

Acutally there are a lot of videos.The engine made the most power on 87 octane (only by 1-2 horsepower) over the higher octane fuel. Lesson is never use more octane than required. Your just wasting money. I leave it to the manufacturer to state the octane requirements of their engine and follow their recommendations.

 

Shell V power
Absolutely the best

 

I just pondered the same…I can find 87 ethanol free but nothing higher unless I went 10% 91; I went with the E free 87.

I just rebuilt my carburetors so I’m uber paranoid about the ethanol; three of four of my accelerator pump jets were plugged.

I can’t definitively indicate what caused the blockage, but I can definitively state that I will do anything to mitigate that from happening, again.


Sent from my iPhone using the awesome FChat App. [emoji869][emoji964][emoji869]

 

I run the high octane fuels from Shell and Exxon, but really only because they have more additives than regular.

 

The only issue I have seen with ethanol gas is if it sits for lengthy periods without stabilizer. It definitely will clog carb parts under those conditions. I have had to totally disassemble carbs for cleaning in that situation. But with stabilizer (like StaBil or similar product) added to the gas it doesn't occur and the fuel is OK for at least a year in storage based on my personal experience storing vehicles. Stabil claims 2 years but slightly over one year is the longest I have personally experienced.

 

If you drive the car frequant enough to re fill the tank once at least a 2-3 weeks go with pump gas of your choice. If you are planning on parking the car long term drain the tank, VP, Sunoco do offer ethanol free fuel by 5gal pails.

 

+1 Ethanol free V power is very good for my 1988/328 no water separation and no attack on the aluminum tanks very easy to find at shell station here in Canada

 

FWIW, V-Power is not ethanol free everywhere.

 

I run 91 in my 328 and 110 Sunoco in my Dino.

 

I always use Chevron 91 oct on my QV for the past 16 years because of their Techron injectors cleaner and she has been running very smooth since. Am I wasting my money and just use 87 oct chevron which also contains Techron injector cleaner?

 

Yes you are right you have to look at the bottom of the V power pump for the sticker

 

If you want to verify the ethanol or lack there of these kits work well. https://www.amazon.com/REV-X-Super-Tester-Flex-Ethanol/dp/B073HLSVHX

 

thanks for posting that video. I assumed it was going to talk about needing to adjust timing to get better HP out of higher octane, but .. nope.

I think i'll stick with no ethanol, though arguably in a fuel injected car it doesn't seem that its all that important. Maybe trade off with 91/93 having the better additives sometimes.
I've read the ethanol free gas will last longer but its doubtful I will ever have that problem .. ... no winterizing here

 

Higher octane fuel is just harder to ignite... It doesn't give you more power when you do eventually ignite it. Using a higher octane than the car needs is a complete waste of money.

Now, base octane has nothing to do with whether or not the gasoline has ethanol in it. Ethanol is a separate discussion.

The only reason to use the more expensive gas is if you want the additives. Just buy a bottle of additive and use it occasionally.

 

You won't have a problem until you do.

They run fine with it.

The problems with water corrosion and rubber disintegration appear eventually.

 

One would think that if it was a problem it would have shown up in the 14 years I have owned the car...

As I've stated, I am well aware that ethanol can cause serious problems if the vehicle is in storage with untreated fuel but I never do that; it's always got StaBil added when the car is not being driven. Same with our motorcycles.

 

The Doc is right the only reason for Ethanol fee gas is rubber life,water,aluminum life