Changed wheels SID settings - MPG value dubious

[BigMike]

Hi,

As mentioned in this thread: http://www.saabtechtalk.com/forum/index.php?topic=1558 I changed wheels from 16 inch to 15 inch.

I also changed the temp sensor as the dash gauge wasn't reading correctly.

My local specialist changed the SID settings to make the speedo read correctly, but left the temperature on the air con unit and the SID displaying in Fahrenheit.

The MPG figure shown on the SID displays as about 25 mpg - prior to this it was reading 29.? around town and high on longer runs.

I plan to get the SID settings changed so the temperature reads in C.  I'm wondering if this could be related to the poor indicated MPG and which values need to be changed in the SID.

Are these values something I can change using on of the inexpensive ODB-II readers you see advertised?

Thanks again for your help,


Mike

[Audax]

He has set your SID to american units, the UK has bigger gallons (almost exactly 20%) hence the difference. I remember one time someone ranting about how their car only did 25mpg so they were going to scrap it, when I changed the sid and it said 30mpg they were over the moon and decided they must keep the car. Change the SID and the units will be correct.

You can change the SID by holding down the right combination of buttons, it should say in your cars handbook.

[BigMike]

Thank you Audax, much appreciated.

Mike