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I recently went on leave with a buddy of mine, we drove home with him following me all the way. We checked our speedometers with each other and found them to be reading the same between both cars. However, when we stopped for gas, his trip odometer was reading quite a bit less than mine. After 350 miles, his trip odo was about 40 miles behind mine. He's driving a '97 Lincolin Mark VIII. Anyone have any suggestions as to what might be causing this? Last I knew, the odometers were driven from the speedo... (yes, his car has one of the old-school mechanical clusters)