My friends aunt has an Altima it consumes oil. They went on a 10 hour road trip to god knows where. On the way back the RPMs at 65 mph jumped from 2k up to 4k. My guesses were Transmission issue, throttle position sensor, or a vacuum leak.They did not feel any slipping or hard upshifting or down shifting. The car was idling at 1k RPMS in park which is normal and was fine up to 65 MPH. When they were 1 hour away the car returned to normal at 65 MPH it was running at 2k RPMS. Vacuum Leak is still a possibility. So is the tranny I dont know much about these cars but if anybody has an idea drop me a line. Thanks in Advance.