Toyota Avensis Trip Computer - Bob Prescott
I would appreciate anyones views on the following

I have a 2001 Avensis diesel with a trip computer as a standard item. The average indicated mpg, over a tank of full, is consistantly indicating 13% better fuel consumption than it actually is. The "Range" left to run on the remaining fuel in the tank, is out in as much as I estimate that it would run out well before the range says zero, wheras the instruction book says that there should be fuel left when it indicates zero. The dealer has changed the computer display, only to make matters worse. Both he and Toyota now say that such errors are within the specification, but have failed to come up with a specification. Has anyone else had any experience with Avensis trip computers.
Toyota Avensis Trip Computer - Bob Prescott
Something that I forgot to add to my query above is that both the dealer and Toyota refuse to accept that the problem could be with a sensor or other system that feeds data to this trip computer. This seems somewhat illogical to me. Anyone have any views