This recipe is delicious and comes from Frank Ostini who owns the Hitching Post Restaurant in CA. The only thing I would suggest doing differently that my DH and I do, is to baste with your favorite smoky barbecue sauce during the last 30 minutes of cooking, instead of the oil/vinegar mixture. We found that the oil/vinegar basting sauce in combination with the fat from the tri-tip caused too many flare-ups and we had tri-tip flambe the first time we made it. =) I believe the cook time is for medium to medium-rare, so you may need to adjust that to your liking. Hope you like this as much as we do! **TIP: Marinate the tri-tip in a marinade made of half beer, half barbecue sauce for 48 hours and it will be even more tender and juicy! When we make this tri-tip we make sure to do this and it always comes out great!