I think my previous 290 was set to either every 8k or 10k for oil service. I did a lot of miles though, so it was every 4 months I was changing the oil. And it did make a difference when changing the oil on those intervals. I only use Millers oil, so it is a bit of an expense each time I change, probably close to £80 for oil, filter and sump plug. Only takes about 30mins or so to change. I still use a VAG specialist to do the minor and major services which include the oil changes, but do the other oil changes between the services myself.