|
I did the voltmeter to sending unit setup with my brothers 90 Civic hatch when I was doing some testing and wanted more accuracy. No other MPG instrumentation. One of the issues that became apparent to me after repeatedly driving a 9 mile loop was the huge variation in tank readings.
It finally dawned on me that after a 9 mile run and a tank reading that was actually HIGHER than when I began that loop, that the return fuel system combined with 90+ degree temperatures resulted in the fuel in the tank heating up. Adding the hot asphalt pavement to raise the temperature even higher made short distance calculations an exercise in futility requiring the car to cool down overnight for decently repeatable readings.
I did see 90 MPG loops without cold starts, significant traffic, no traffic lights, and P&G engine off from 25-40 MPH, but even the heating and cooling as the daytime temps increased the heat content and expansion of the fuel in the tank made true precision an exercise in frustration. Even parking in the sun affected the readings versus parking in the shade, when you consider the asphalt was probably at a surface temperature of over 150 degrees in direct sunlight.
regards
mech
|