Good point on octane - premium high octane fuel also has lower BTU content per gallon - unless you have the high compression ratio [or turbo] which increases the engine's thermodynamic efficiency you are immediately losing fuel economy by using 'low BTU' gasoiline.

Last edited by jmoser; 04/04/07 03:39 PM.
Jeff
96 T100 SR5 4WD Ext Cab, Warn Hubs, HD torsion bars, Bilsteins, Camper Shell, TJM bar, factory 31 x 10.5's, Powertrax No-slip rear, Recaro driver's bucket