1592 fuel recommendations

[hayesbd]

I have a 1973 Spider with a stock 1592 running the static timing at around 10 degrees BTDC. According to the shop manual, the compression ratio is only 8:1, so I filled up with 87 octane fuel. So far, I haven't noticed any pinging. From searching the site, it seems that a lot of people run much higher octane, even on stock engines. Does anyone else run 87 octane on this particular engine and does it give you any problems?

Thanks,
Brian

[vandor]

From an octane standpoint, 87 is fine for your car.
However, if your car sits for longer periods of time, consider using premium. In most areas premium does not have any ethanol in it, which separates from the fuel and absorbs water if allowed to sit. This can wreck an old car's fuel system.

[Exit98]

Csaba,

You're one of our valuable experts here and I for one appreciate the time and effort you spend on this board.

I do think you are mistaken about ethanol and premium fuel. Ethanol is an octane enhancer and it is very likely that it is in virtually all the premium fuel available at the pump. Possibly things are a little different in your neck of the woods, but I doubt it. My research indicates that non-ethanol fuel is essentially unavailable anywhere outside of airports. I can't offer direct web back up but if you google "premium and ethanol" I think you will come to the same conclusion.

Ethanol is miserable for our Spiders' fuel systems.

Separately I'd emphasize that paying 25 to 35 cents a gallon more for premium fuel for our Spiders, and in fact probably for 90% of all the cars we collectively own (Maytag's excluded) is a huge waste of money. Our modern cars will adjust timing to avoid detonation. You are not likely to even notice the negligible decrease in performance.

[Dawgme85]

I have had problems (missing, hard starting, etc) with "normal" gas (i.e. gas with added ethanol) in my spider, so I make a point of knowing where I can find ethanol-free gas while traveliing. EF gas can be found at many Grange stations and, luckily, one of these is located just a few miles from my house.

As a rule, I run mid-grade (89 Octane) ethanol-free gas in SHELOB, with no problems. The manual recommends 92 Octane, but I'm of the opinion that this isn't necessary due to the low compression ratio of the engine (8:1 or 8.5:1?). Regardless, pre-ignition/pinging isn't an issue.

You can find a list of ethanol-free stations in your area here:

http://pure-gas.org

Good luck!

[Exit98]

You can find a list of ethanol-free stations in your area here

Yeah, that's the problem. There are 3 listed in New Jersey and two of them I don't think are actually gas stations. At least on both coasts we're pretty much SOL.

[vandor]

>I do think you are mistaken about ethanol and premium fuel.

It is possible, as it was info I got from another automotive webpage and have not verified it.

> Ethanol is an octane enhancer and it is very likely that it is in virtually all the premium fuel available at the pump.

While ethanol does enhance octane, it used to not be in any of the automotive fuels, including premium.
It is not added to fuel to enhance octane, but as a requirement to "reduced dependance on foreign oil".

> My research indicates that non-ethanol fuel is essentially unavailable anywhere outside of airports.

I have not done any research yet, but was going to check if there is any truth to the ethanol-free premium fuel info.
It would be really good for our old cars...
bye,