The tires are inflated to 45 psi, I have a K&N air filter, I've removed the stock "Y" shaped airbox intake horn, so there's just a hole going into the airbox, and I've put a hot air intake from the exhaust manifold over to the intake box. There's also a front air dam that is just tall enough to reach below the dangly bits under the car, so that the airflow is diverted from *some* interference.
Keep in mind that this mileage is on the open highway, with a fully warmed up engine, one passenger, no AC.
The latest tank is 36mpg, that's around town from home to work and such. I tried to P&G as much as possible within rush 'hour' traffic. (Rush minute, in my little home town...
)
I still want to build a 555 timer circuit that will make a 1.5 volt variable frequency/duty cycle square wave that I can add to the Oxy sensor's output, to convince the ECU that the engine is running a little richer than it really is.
The engine has about 160,000 miles on it, so it's well broken in by now...