Lots of misconceptions about octane. Octane is a measure of how well the fuel resists detonation. Higher octane gasoline has less energy per weight than lower. So, if you truck is not pinging on the gas you are running, switching to higher octane will not make it run better, and may make it run worse. You will see a slight gain from higher octane if you get a chip specifically mapped for it, but as Mike points out there are much greater gains to be had elsewhere.

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I'd rather have a bottle in front of me than a frontal lobotomy.

'84 Alan Record Carbonio, Aerospoke wheels, Campy brakes.
'00 SVT Lightning, silver, G-tech Pro, JBA headers, cam bolts, 4.10 gears
(soon, Swanson's chip and MAF, Cal-tracs)
2001 Kevlacat 2400, twin 115 Evinrude FICHT, Raytheon VHF, Radar, and Sounder/DGPS chartplotter

gmvye@pacbell.net