Mine is very accurate, no more than .1 off. It does take into account idle. If you turn your car on and leave it there, you'll see the MPG meter go down.
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Kenwood DDX616 | Polk DB6501 | Llumar 23% tint | STi-R Clear Lens
SSR Type-F | F.I. 18" CF | Stillen Gen 3 | KW V3
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