|DISCLAIMER : 195/60 R15 tires until 2007/05/30. This car originally had 185/65 R15 tires. This would mean that my current MPG totals are 1% greater than they should be. For now, I am going to leave the data the same (so many mileage entries!!!!) but increase the EPA combined value by 1, from 31 to 32. This will keep me from becoming a "fake" Hypermiler.
UPDATE : As of 2007/05/30, I now have 195/65/15 tires, which would mean that my new MPG totals will be 2% less than they should be. This will be fixed by increasing my total miles driven by 2% and documenting this action in my gaslog. This will be retested every 6 months because normal tire wear will reduce this % over time.
Old EPA vs New EPA MPG Figures :
Old: 27 City/38 Hwy => 31 Combined
New: 23 City/34 Hwy => 27 Combined
K&N Air Filter
Denso Iridium Performance Spark Plugs
12 Volt "cigarette lighter" personal fan to avoid using AC
2006/09/10 - Removed Air Dam
2006/09/30 - Switched to 192-195 Coolant Thermostat (Napa Part #THM268)
2006/10/28 - Front wheel spoilers (modest aerodynamic upgrade)
2006/11/28 - Experimenting with Warm/Hot Air Intake, fiddling to get it right.
2007/01/04 - Warm Air Intake offline
2007/01/08 - Warm(er) Air Intake online
2007/01/27 - Hydrogen Generator installed, full function pending
(I got the generator from www.hydrogen-boost.com)
2007/01/31 - Hydrogen Generator online. Supplemental components pending.
2007/02/02 - Disabled DRLs (Daytime Running Lights) for saving up to 10 Amps on daylight commutes.
2007/02/04 - Reduced to 37 PSI for coming week of rain
2007/02/16 - 1/2 Grill Block
2007/02/24 - Replaced my 2 narrow-band 02 sensors, pre and post catalytic converter. Replaced Engine Coolant Temp sensor. Switched from 20W50 to 10W40 engine oil. Why the thick oil to begin with? I thought I had a tappy valve problem that turned out to be a loose headlight adjustment screw. Go figure.
2007/02/27 - Full Grill Block
2007/02/28 - Removed Grill Block
2007/03/05 - Constricted cold air intake from 2" diameter to 1" diameter. This increased IAT temperatures to about 140+ degrees F on the freeway. Previous average was maybe 121 degrees F.
2007/03/18 - Installed Manual Fan Radiator Switch, don't need to turn on AC to engage electric cooling fan.
2007/05/27 - El Cheapo (Ultra Cap?!?!) Battery/Electric Stabilizer
2007/05/30 - New Tires : Continental Contact-Pro 195/65 R15, one size up from stock. Rated at 51 PSI, running 40 PSI.
2007/06/27 - IAT Resistor Mod. 220 Ohm for steady 200 IAT reported to ECU/PCM.
2007/06/29 - IAT back to normal
2007/07/05 - Starting FFT fuel treatment test
2007/07/21 - Radio Antenna delete (just ran a wire attached to the antenna connector up the A-pillar. AM reception not great, but good enough)
2007/07/30 - Control Button for "steady state" CC Cruise Control, not working as desired yet.
2007/08/01 - Switched to Wix air filter after reading this thread (thanks psyshack!) :
2007/08/02 - Digital A/F ratio gauge online
2007/08/08 - EFIE online and in testing state.
2007/08/22 - EFIE being used conservatively, when TPS is zero.
2007/08/31 - 5th gear swap from MP2 to MP3 Saturn transmission.
2007/09/xx - Rotated tires.
2007/09/24 - Raised Tires to 50 PSI.
2007/12/02 - Installing AirTabs, on rear roof so far.
2007/12/21 - EFIE OFFLINE to test MPG without it.
2008/03/25 - Original Radiator replaced with non OEM version at 154,947 miles.