fuel RON's

nncoolg · Post by **nncoolg** » Mon Oct 25, 2010 5:12 pm

I have always been a little dissapointed by our maximum 98 RON fuels, well I just came back from Hawaii, and get this - the fuels on offer there are 85 & 87 unleaded and 92 V-power! how's that! They are obsessed with 'gunk' though-so many ads on TV from oil company's and stuff reminding everyone to change their oil to prevent 'engine destroying gunk' the shell fuels listed above are even advertised as containing nitrogen to 'stop the gunk'

good times!

someguy · Post by **someguy** » Mon Oct 25, 2010 5:57 pm

I use a minimum of 98RON on all my cars.

Even my EA82 runs smoother and has a little more kick once I run a few tanks of 98 through it (don't rotate between 98 and 91 due to price changes, if you stick to 98 for 3-4 fill ups it will reward you)

Gannon · Post by **Gannon** » Mon Oct 25, 2010 6:00 pm

Hey good to see you're back.

Dont forget that the US measures their RON differently us and the Japs.

Octane Rating - Wikipedia

the octane rating shown in the United States is 4 to 5 points lower than the rating shown elsewhere in the world for the same fuel.

nncoolg · Post by **nncoolg** » Wed Oct 27, 2010 6:01 pm

thats interesting, if that wiki entry is true, it would certainly make sense. Looks like the rental Yaris got a nice dose of good fuel then, cause I gave it a whole tank of 92

steptoe · Post by **steptoe** » Wed Oct 27, 2010 9:48 pm

You filled it up ?? One of my brothers mates 20 years ago was known for his...thriftyness. Went to all the trouble to remove seats etc of a Starlet to bend the sender to read full on the gauge before he returned it to the rental crowd. A little smarter and he could have saved the effort and just earthed the sender. Certain NZ authorities watching in case he returns

nncoolg · Post by **nncoolg** » Thu Oct 28, 2010 5:14 pm

sammynb · Post by **sammynb** » Thu Oct 28, 2010 6:46 pm

Not that I'm advocating using lower RON fuel but isn't there an article online about cheap, effective modifications for either ea81s or 82 engines and the author recommends using the lowest RON fuel available?
It had some good basic tips to gain a few extra HP but I remember questioning the use of 91 fuel over 98.

sammynb · Post by **sammynb** » Fri Oct 29, 2010 1:27 pm

Found it!
From the Subarus of the 80s site: http://www.indysworld.com/80s/general/e ... mance.html

Fuel

Gasoline? Who cares! Just put premium in the tank and everything will be tine right? Wrong! You should ALWAYS use the lowest octane fuel that your car can tolerate without detonation. Why?

Well of course the lower octane fuels are cheaper, but there's another reason. Lower octane fuels burn at a faster rate than higher octane fuels and contain more BTU'S (British Thermal Units) per equal measure. In short it takes less 87 octane gasoline to produce the same power of a 93 octane gasoline.

'I'he octane number is NOT a measure of the power-producing ability of the gasoline. The octane number is simply an index to relate the anti-knock (anti-detonation) properties of the gasoline. The higher the number, the more resistant the gasoline is to pre-ignition. (ignition of the fuel before the spark is applied) or detonation. The flash-temperature, or temperature the fuel will spontaneously ignite, is much higher for a high octane fuel. So a higher octane fuel takes more energy to make it ignite and releases less energy as it burns.

Since the lower octane gasolines contain more potential energy, it takes less to make the same power in your engine. The result? slightly better fuel economy and better torque.