Last night I went to my local Mobil station filled up my 540, Got in started and went. I didnt think much at first but by the time i hit 3rd gear i noticed the car had a loss of power. The tach showed higher rev than normal. At 6th gear around 70mph flat road i rev about 2500 +/- 200, my 540 was reving at 3400rpm..weird. I arrived at my destination. Went in had a drink later when i started to go home the son of a bitch was back to normal...anyone have a clue???