How many miles before an oil change on 2003 audi

DON'T TRUST AUDI MANUALS, MY 2003 A4 PLUGGED OILS LINKS ONLY AFTER 5000 MILES. VW STRETCHED THE MILEAGE OUT TO MAKE A PROFIT AND I REALLY RECOMMEND 4000 INTERVALS, NO LONGER -AT A US EAST COATS TEMP RANGE OF FREEZING TO 10 BELOW TO 15 C - 20 C.

AUDI ENDED UP INCREASING OIL LINE SIZES AND ENLARGING THE OIL FILTER BY 50% AND TELLING ME TO USE THE NEW FILTER FROM THEN ON.

SO LESSON LEARNT, EVEN WITH SYNTHETIC, DO NOT GO BEYOND 4,000 OR BAD THINGS WILL HAPPEN -CALLED ENGINE SLUDGING UP

Consumer report says 4 to 6000 miles with good oil. I would stay with 4000 miles and filter. Synthectic oil can go longer - see mfg specs
on line

It depends if you are driving in a hot or cold country
and check the owner manual you will get the answer