Tri-tips are like grilling or smoking a brisket to me...just in a smaller version. Got to pay attention to the temps...meat probes are good for them, just like briskets.
@Jon1212 nailed that one if going for med rare to medium. You can get medium rare to medium on the same piece of meat, Tri-Tip, same as on a big packer brisket. Depends on the end of either nearest the exit smoke, i.e. chimney stack. Depending on smoker or grill, you can get the best of both worlds...Med rare and medium all in the same deal. Keep the probes on the leading end of the meat nearest the exit smoke. If low and slow, the end nearest the stack will always cook s few degs more than the opposite end. Pay attention to the bottom dampers and airflow as it goes though the stack, keep the temp where you want it. This is the deal breaker for smoking or grilling low and slow, 8/10 hrs or more. Don't get the meat too hot too soon. That's where a lot of folks *f-word up. They open that lid, they get anxious, wanna get the groceries, wanna show their buddies what's on the smoker. Bad mistake. I open my Traeger or my Snoke Hollow once an hour, real quick, if what I'm smoking needs a quick pump down with the juice. If it don't need no juice, don't ever open the lid or door. Don't open it. There's a helluva difference in the smoke ring and the texture of meat at 180-200 degs low and slow, compared to 250 degs low and slow. Once the inside probe-wise gets near its target, you can slick up and bark the outside any way ya want with any sauce. The outside is already barked by that time, just saying if a wanna add your sauce that you like. The inside is a done deal and that's what matters. Enjoy your grillin and smoking fellas. I been trying to perfect my grilling and smoking after damn near 35+ yrs. I've had it down for many yrs now, depending on what meat is hitting the grill/smoker. It's all about the temps fellas and give it time...and no looking.
Jeez...I can't believe I bumped my gums this long. Lol