Your one mistake here is believing the inherantly inaccurate stock gauge. Numerous studies have established that the reading is usually wrong due to an Italian-made gauge and a US-made sender. In addition, there are two gauges and at least three senders possible; some combinations are more accurate than others, and one is so far off, it does not qualify as a gauge! Check the archives for the background on this problem (bring along a chair; it'll take a while).
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