Data here! Get your data here! Get it while it's hot!
 

I have a cable that lets me log some data on my laptop. I'll only have it for a short time. Anyone have any questions they want answered by data? Of course my data is specific to my car and driving, but it can probably still apply a lot to other cars. I can log any 4 at a time of the following:

03: Fuel system 1/2 status (Open loop vs. closed loop -- I believe this differs vastly from other vehicles, as mine doesn't go open except in DFCO)
04: Calculated load value
05: Engine coolant temperature
06: Short Term Trim Bank 1
07: Long Term Trim Bank 1
11: Intake Manifold Absolute Pressure
12: Engine RPM
13: Vehicle Speed
14: Ignition timing advance for cyl #1
15: Intake Air temperature
16: Mass Air Flow
17: Throttle position sensor
18: Secondary Air Status
19: Location of O2 Sensors
21: Bank 1 Sensor 2 Status
22: Bank 1 Sensor 3 Status
28: OBD Requeirements Met
31: Time since engine start
33: Distance travelled with MIL active
46: Commanded evaporative purge
48: Warm-ups since DTC cleared
49: Distance since DTC cleared
51: Barometric pressure
52: Bank 1 Sensor 1 Status
60: B1S1 Cat. Temp.
62: B1S2 Cat. Temp.
66: Control module voltage
67: Absolute Load Value
68: Commanded Equivalence Ratio
69: Relative Throttle Position
70: Ambient Air Temp
71: Absolute Throttle Position B
73: Accelerator Pedal Position D
74: Accelerator Pedal Position E
76: Commanded Throttle Actuator Control
81: Fuel type
86: Long term sec. O2 trim bank 1/3

What's #81: 'Fuel type'?
Might that be the car's interpretation of the octane rating of the fuel you're using?

I'm almost entirely sure that it's diesel vs. gasoline, but I'll have to try it and see what it says the next time I drive that car.