What weight was the synthetic oil?? Today’s synthetics are usually 0W20, an extremely thin oil with great film strength that give high miles per gallon and good low temperature starting.
Unfortunately your Saturn was designed likely with looser clearances and for 5W30 mineral oil. Many older cars start “using oil” when switching to synthetic.
That’s why now car manufacturers state in the owner’s manual that 1 quart per 1000 miles is considered “acceptable”. I rented a Toyota a few years ago and the statement was there all right. The engine used 0W20 synthetic and Toyota was aware that under very hot conditions this engine would use oil.
These things are all done to meet Obama fuel consumption standards.
So, just check the oil more often and add as needed. Switching back to 5W30 mineral (non-synthetic) oil may slow the oil consumption.
My wife’s Mazda 3 was designed to use thin oil and experiences no consumption during the 5000 mile drain interval.