My Speedo, odometer, fuel meter etc is converted from km/h to mph (im a JDM er), so the centre clock still says km/h but its actually mp/h. My dte reads about 450 (miles) when i fill it up, but ive only ever managed about 280miles before a re-fill. dte seems to only get accurate with under 150miles left on it, at least on my converted example.
Jamie