[fatcatzzz]

Not sure what you are seeing on your map. Maybe the old highway, but if I was going over the Grapevine headed to Oxnard. I would stay on I-5 south to Hwy 126 just north of Santa Clarita. Hwy 126 to Hwy 101 in Ventura, Oxnard just a few miles south. Been this route several times with our 5r. Grapevine is a long 6% grade, so take your time, use gears or exhaust brake and you will be fine.