electrical and ignition Fuel options

[mlcrum]

Would like to hear some opinions on fuel options. Non ethanol gas is becoming hard to find in my area. A couple of stations offer 89-90 octane non ethanol. Most offer 87, 89 and 93 octane with ethanol. Which is better 90 Non-E or 93E? I have been using 93E but treat it with stabilizer. My 02 has 292 cam and DCOE 40s. One other question. A couple of stations offer 100 octane. Would it make sense to blend a gallon or two into a full tank of 90Non-E to boost the octane?

[zinz]

What's your compression ratio? That's the key to answering your question.

 

Higher octane gas is used for those with high compression engines, subject to pre-ignition, or "pinging".  If your engine doesn't ping using gas with a lower octane, then don't spend the money on the expensive stuff... it's not necessary.  

 

I wish there was a station near me where I could buy non-ethanol gasoline... that alcohol is terrible on the rubber components of our old fuel systems. Not to mention the poor fuel economy you get by using it.... I hate it with a purple passion.

 

Ed

 

 

[mlcrum]

Thanks for the reply. The compression ratio is 9.5:1. I should have mentioned that detail. I haven't experienced any pinging with 93E.

 

I find my non ethanol at Shell stations. The octane was as high as 93 but dropped to 89 about 8-12 months ago. It's usually a price premium of $0.25-0.50/gal.

[zinz]

No problem...

 

Well-maintained engine shouldn't have any troubles running a lower octane gasoline with a 9.5:1 CR.  If you can't find anything but ethanol-based gasolines, you'll want to add something like Marvel's Mystery Oil to the gas to help keep seals from drying out.  Marvel's is a good upper cylinder lubricant, as well.  

 

Ed

[mlcrum]

Thanks! And will check out Marvel's. I do run some Sea Foam in my fuel from time to time. Good product as well.

[Hans]

I saw a Fastrac station in upstate NY that had 93 non-ethanol. I don't know if that is a big chain, and may not be top tier, but good combo.

[elfhearse]

http://www.pure-gas.org/index.jsp?stateprov=NC

 

Looks like one 90 octane station in Huntersville,  Cashion's Quik Stop Hwy. 73

[TobyB]

89 is fine.

 

If you can run it without pinging, 87 will get better power and gas mileage.

 

t

 

[Mike Self]

My '73 has 9.5 pistons and a 284 cam; I can use 89 octane (w/ ethanol--seems like that's all we can get in our part of Ohio) with no pinging problems at all--at least here in flatlandia.  If I take a drive down to Vintage through the mountains, I fill up with premium for pulling grades.  

 

To my surprise, my E30 318is seems to be happy with the same setup--89 for around here; 91/93 for the mountains.  And E30 M42s don't have knock sensors.

 

mike

[TobyB]

Huh- the E36 version has 2 knock sensors- and mine both use them if you lug the engines on 91...

 

I find fastest times in the M20E30 with 87 octane- but the plugs come out just a little... scary.

89 is slower- and probably safer...

 

t

 

[M3M3]

Don't worry about ethanol gas.  if you still have old rubber in your fuel system,  you need to do some serious maint on your car.   fuel hose design was changed decades ago to accommodate e-fuel.

 

I have never had any issues with ethanol in any of my cars and that is all I run.  

[Simeon]

38 minutes ago, mlytle said:

Don't worry about ethanol gas.  if you still have old rubber in your fuel system,  you need to do some serious maint on your car.   fuel hose design was changed decades ago to accommodate e-fuel.

 

I have never had any issues with ethanol in any of my cars and that is all I run.  

 

Does that go for KFish injection too? I thought ethanol had been fingered for problems there?

 

Certainly all of the new performance V8's in Australia are tuned for e85 (85% ethanol fuel) so apart from compatibility with rubber and plastic in the fuel system it isn't a bar on performance. 

 

Its also worth saying that if you don't have a rip snorting, high compression engine there is no point in running too high an octane fuel. The higher octane actually reduces the volatility of the fuel and makes it harder to ignite. 

[adawil2002]

1 hour ago, Simeon said:

 

Does that go for KFish injection too? I thought ethanol had been fingered for problems there?

 

 

In the 6 years I've owned Vern, I have had zero problems with 10% ethanol blended fuels. 

[Hans]

i think the larger problem with ethanol fuel is leaving it in the tank for more than a few months. While i read about rubber degradation, has anyone actually experienced that? As Mlytle points out, most old rubber lines should have been replaced, but are we sure that newer fuel pumps, for example, are built with appropriate ethanol-resistant diaphragms? Our Shell premium in Canada is zero ethanol, and that's all I use (especially for winter storage). Have to say though, cars haven't so far exploded when I drive in US on corn syrup.

[TobyB]

Quote

the larger problem with ethanol fuel is leaving it in the tank for more than a few months

This.

It takes a mighty trick additive package to keep water and oil mixed, and it doesn't store so well.

Then the corn alcohol starts to soak up moisture, and corrode and clog everything in sight.

 

The alcohol racers have a pretty rigorous shut- down to purge alcohol.

 

t