So here's the official word on the matter: Technical Bulletin No 334 from Chevrolet describing Distance For Remaining Fuel Logic Driver Information Centre (DIC)
It says:
"The DIC is programmed to display the most accurate Distance For Remaining Fuel reading as possible.
Due to the Saddle type fuel tank, the fuel level in the left compartment can differ from the right. Therefore each compartment has its own fuel level sensor, so with a half-empty fuel tank, the left can be completely full, while the right will be completely empty.
To make the calculation for Remaining fuel the Engine Control Module will measure one side then the other, this delays sending of information to the display. This is most prevalent after refueling, the calculation has to count down before it's able to display the correct distance.
The remaining distance reading will differ from the actual distance because of different driving patterns, driving conditions and speed.
The readings on the DIC are also affected by the Diesel Particulate Filter (Emissions Control). During regeneration the Control Unit commands the engine to burn off excessive soot in the filter by injecting increased amounts of fuel. During this process the Distance reading will drop due to increased fuel consumption.
None of the above affect the actual fuel gauge because of a software damping process in the instrument cluster.
This is a characteristic of the DIC system and repairs under warranty should not be attempted."
Now, all of this seems to me to be flawed logic and will never produce "the most accurate Distance For Remaining Fuel reading as possible". If there are independent fuel level sensors in each side of the tank then why can't it simply read these and calculate correctly on refueling. I know its never going to be 100% accurate but to continue to count down to zero miles after refuelling just makes no sense whatsoever. This looks like sloppy coding to me and Chevrolet should be ashamed that their fuel distance reading just doesn't work properly.
Can anyone advise me on how to take this up with Chevrolet?
Edited by: placidpete