It is my understanding that during the World War One period the gasoline of the time had an octane rating of around 40??

Does anyone know when they started making gasoline in the 87 or modern range? Does anyone know when and what this break thru technology was called or who researched it?

Thanks

Octane rating has nothing to do with how much energy the fuel has, but rather what its resistance to premature combustion is. Having an octane rating in the upper 80s means that you can be fairly sure when the explosion in the piston will occur. The improvement was better refining, to include only octane and iso-heptanes in the fluid.

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Perhaps they added a lot of ethyllead. That works by SLOWING the burn incidently.

These days they have to increase the proportion of aromatic hydrocarbons to give the same slowing as the lead.

Jimmy Doolittle left the Army in the 1930s and went to work for Shell Oil. One of his biggest projects was to develop and market 100 octane aviation gasoline. At first, it wasn't very successful. Some even called it "Doolittle's $6 million dollar blunder."

Then a funny thing happened. Someone tested his high octane fuel in a standard fighter plane of the time (P-13?) and found it could fly much faster. Doolittle no doubt knew this from his racing days because racing pilots had been adding lead to their fuel for some time. The lead allowed the engines to produce more power without knocking.

I've read that one of the things the US did to help England in 1940 was to ship them high octane aviation fuel. When you consider just how close a thing the Battle of Britain was, any small measure of improved performance in the Spitfires and Hurricanes had to help. This is discussed briefly here.

Further, thanks both to prewar agreement and wartime sales arrangements, American suppliers delivered sufficient quantities of performance-enhancing 100 octane fuel to England in time for use by RAF Fighter Command during the Battle of Britain, a contribution of profound significance to the operational success of both the Spitfire and Hurricane fighters.

Power and fuel economy can be improved if the compression ratio is increased. See below.
That's why the octane number is important. A fuel as resistant to premature combustion - 'knock' - as well as 100% iso-octane (2,2,4-trimethyl pentane) has an octne number of 100. One as prone to knock as n-heptane has a number of zero. It's that arbitrary.
(And the US standard method for determining this is different to the UK one, so that RON (Research Octane Number, US) is about 10 more than MON (Motor ditto, UK) for the same fuel.)

For these reasons, the use of a supercharger was essential to give the Spitfire (and the Lancaster) it's high altitude performance, and high octane fuel was essnetail for that. See: http://www.spitfiresociety.demon.co.uk/engines.htm

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Interesting responses gentlemen, thank you, does anyone know what the octane level of WWI era actually gasoline was?

Cool, thanks for the details.

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if your car runs good on 87 octane, don't assume that it will run better on 89, 91, or 93 octane. if it's optimized for 87 octane gas, the slower burn of the higher octane fuel could kill your efficiency by quite a bit, or at the very least cost you more money to drive the same amount of distance.
next spring- funds permitting, of course- i'm gonna build me a high compression engine so i can run 100+ octane E85 in my 1974 Monte Carlo without giving up the mileage or power that i'd give up by running it in the stock engine that's in it now that was built and tuned for 89 octane gas.
it's gonna be fun..

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1918 gasoline had 36-40 octane although kerosene was sometimes mixed in which lowered octane toward the 25 end.

Not til the mid 20's did octane reach 60 due to the use of tetra ethyl lead.

Catalytic petroleum cracking led to present octane ranges just before WWII.

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