Looking at the possibility of installing a ByPass filter system on my Volvo 4 cylinder Turbo. What am I looking at for total installation cost for a good system. And what is and who makes a good system for an automobile? It is really tough for me to get over 3000 mile OCI's even though I'm up to 4500 mile OCI on M1 10W30 with Volvo recommending 5,000 mile OCI. Last week end I got laughed at by two mechanics when I said I changed my Synthetic oil between 4K and 4500 miles. They were not laughing because it was too long of an OCI.