Jun 28, 2015 - 10:49 AM
The page Annika referred to includes all our suggested hikes, and allows you to filter on hiking time. There are only two between 4 and 6 hours. Beware that this is pure hiking time without breaks. So 6 hours is really long and such a hike should be started early.
Please click "Where it's valid" on the pass pages Annika gave you. That will show you what's included. You may also want to look into the Swiss Half Fare Card if you aim to drive as much as possible. My suggestion would be however, to park the car in Grindelwald and use the trains. They're excellent and an enjoyable way to travel. Traveling by car restricts you to circular routes or at least to travel back to your car once done hiking.