hello, ive done all servicing per owner’s manual at vw dealership, which manual states is a 1 year, 10k mile interval. this year ive driven less so my 1 year oci arrived at 87k miles in june, when i did the 90k mile service. i’m no longer doing long highway drives, mainly just 20-30 suburban trips with an occasional 60mph stretch. i’ve noticed a bit of a clatter at idle with this n.a. 5 cylinder engine, but nothing terrible or causing reduced performance. mpg is easy 25 town, 36+ highway. should i go to a 5k mile oil change in addition to the regular 10k mile service? if yes, should i simply return to the vw dealer for a $70 synthetic (vw spec) oil & filter change, or try a new vioc where i have some cheaper promotional coupons? i just replaced the tires and battery so likely will keep this otherwise decent, paid off passat for a couple more years. thanks.