How do I know how fuel mileage is calculated for my 97 Volvo 850 (non-turbo, stick shift)? The Automatic site says, "To see whether your car’s MPGs can be calculated more accurately [i.e., through sensors] or less accurately [i.e. through EPA estimates] by Automatic, check it on our Car Compatibility page." The comparability page though only says if the Automatic Pro, which I already purchased, will work on my car - it shares no specifics. Thank you!