socalgirl

Happy Pre-Thanksgiving Day...
Just curious what gas you recommend for me to use in my beauty!
1984 5 speed 114000 miles

Thanks AND HAPPY GOBBLE GOBBLE DAY!

Alan

Premium min 91 octane and as much more than that as you can get locally up to 93 octane (R+M)/2. Brands - doesn't matter as long as its reliably good... e.g. I wouldn't drive down to Tijuana to fill up...

Injector cleaning additives may help...

Alan

Jim bailey - 928 International

It was designed to burn 87 octane regular. The USA engine is low compression less than 9 to 1 and will be quite happy with the lower cost lower octane fuel with no reduction in power or performance. Anything "better" is a waste of money.

Shane

What Jim said...^^^^^^^^

Alan

Ah yes - Jim is right (as usual) you have lower compression... - ignore what I said - still don't drive it to Tijuana unless you already have a full tank!

85fortheDrive

Here is a recent thread/poll I started on this very topic...

https://rennlist.com/forums/928-forum/389633-octane-poll-for-16v-cars.html

AO

Yep... 87.

SeanR

No ****?

I've been pumping 93 since day one..... am I really wasting $$?

RngTrtl

Only waste of money if car was no designed to run on it. Higher octane rating essentially raises the stability and the ignition point of the fuel. This is required when compression ratios are increased or ignition timing is advanced. If the motor was designed to run on 87 fuel and the motor is unchanged then money is wasted on the higher octane fuel.

Here are some snippets from wikipedia

"Higher octane ratings correlate to higher activation energies. Activation energy is the amount of energy necessary to start a chemical reaction. Since higher octane fuels have higher activation energies, it is less likely that a given compression will cause knocking. (Note that it is the absolute pressure (compression) in the combustion chamber which is important - not the compression ratio. The compression ratio only governs the maximum compression that can be achieved)."

"It might seem odd that fuels with higher octane ratings explode less easily, yet are popularly thought of as more powerful. The misunderstanding is caused by confusing the ability of the fuel to resist compression detonation as opposed to the ability of the fuel to burn (combustion)."

Mongo

Stay at 93. YOu have a 10:1 compression car. Any US 928 before 1985 could run on 87 octane.

I'd recommend 89 because I've had some bad 87 octane in my life for my 944. I won't touch 87 anymore after my experiences.

anonymousagain

Hold up there Sean - your sig states S4's in the paddock ==> 91min for you.

Sharkbody

Treat the ones you love to the very best.--- Perhaps 87 comes in a box with a spout. G

hacker-pschorr

I would first theck for stock timing before dumping in 87 octane.

If the previous owner jacked it up 10 degrees (like more than a few OB owners I know) then 87 octane is no longer such a good idea.

Jim bailey - 928 International

The 32 valves need high octane. The guy who named 91 Octane as "premium" was a marketing genius there are millions of people who insist on feeding their cars the high priced spread in the belief that it is somehow better for a car not designed to run it.

icsmike

So on a 86 32v with a chip whats the best performing fuel to run?