My Most Recent Mods:

My most recent aerodynamic mods are sealing up the wheel wells from the engine bay to reduce wheel turbulence:
                       

I have stopped using the Amsoil 5w30 and I'm now using Millers Eco Longlife 5w30 and doing extended drain intervals.  I am keen to try Royal Purple API spec 5w30 since I got fantastic results for reducing friction with it on my v8 in my truck.  The Amsoil low viscosity ATF is the lowest viscosity full synthetic Dexron VI spec fluid around so still loving that stuff.

For vehicles tuned for 91 octane, it may help to use a mild octane booster.  I have had great results with Millers Petrol Power Ecomax using 1 mL/L and STP Octane Booster using 2 mL/L.  I am also having success using 1 tsp of raw tungsten disulfide (ws2) mixed with approximately 150 mL of Lucas Fuel Treatment with Upper Cylinder Lubricant per 60L of fuel.

I have also recently discovered that LED headlights and driving lights can save a lot of power and as a result improve fuel consumption.  Audi has already done this and has EU certification for this as a fuel saving technology.  As a result, I have installed some Cree-based 3000 lm headlights in the low beam of my headlight and replaced the corner ambers with LED by removing the amber lense in the housing entirely.   Winter and night driving fuel consumption has improved by up to 2 us mpg.  I had to use resistors to eliminate the hyperflash problem of the LEDs not drawing what the old 3157's used to draw.  I found 50W 3.6 ohm resistors were enough.   I used headlight housings that I bought from ebay after my first set were melted and scorched by the DRL overheating problem so I painted the original factory ones.  Here are the pics and you can mouse over for the descriptions:

                    

My fuel numbers are approximately on par with last year but I have recently switched from Shell VPower 91 Super to Esso Super 91 which also contains no ethanol.  I got a smokin' deal on 5 x $100 gift cards that made it too hard to turn up (paid $435).  However, I'm thinking if I switch back to Shell after I'm through all these gift cards, I should see a noticable improvement again.  I'm also suspecting that the Millers isn't as longlife as the 100% Signature Series from Amsoil and I'm thinking of doing an oil change after I'm done with Esso gasoline.