The platinum tipped OEM spark plugs in a 5th MK5 2005-2010 or 6th MK6 2011-2014 generation Volkswagen Jetta should be replaced every 40,000 miles. To view my DIY tutorial for the procedure including replacement part numbers, click on the text link or thumbnail image below.
VW Jetta 2.5L I5 Engine Spark Plugs Replacement Guide
