Tennessee is known for having one of the best Home fields in the nation, but that hasn't really been the case for a long time now it looks like. These are some of their home OOC games since 2003: 

2003 - Tennessee vs Marshall 34-24 W

2004 - Tennessee vs ND 17-20 L (This is the ND team that BYU beat, Tennessee won the SEC E but still lost this game)

2005 - Tennessee vs UAB 17-10 W, Memphis 20-16 W

2006 - Tennessee vs Air Force 31-30 W

2007 - Tennessee vs Ark St 48-27 W

2008 - Tennessee vs NIU 13-9 W, Wyoming 13-7 L (ouch, same wyoming team that we beat 44-0)

2009 - Tennessee vs UCLA 15-19 L, vs Ohio 34-23 W

2010 - Tennessee vs UAB 32-29 W (OT)

2012 - Tennessee vs Troy 55-48 W

2013 - Tennessee vs South Alabama 31-24 W

2014 - Tennessee vs Arkansas State 34-19 W

2015 - Tennessee vs Bowling Green 59-30 W

2016 - Tennessee vs App St 20-13 W (OT), Ohio 28-19 W

2017 - Tennessee vs Umass 17-13 W, Southern Miss 24-10 W

2018 - Tennessee vs Charlotte 14-3 W

While most of these games are victories, Tennessee every season plays a garbage team much closer than they should, or in some instances allows a bad team to score way more points than they should (Bowling Green scoring 30, Arkansas St scoring 27). Tennessee might have the talent to beat BYU easily, but the game will likely still be close. They could only muser 14 points against formerly FCS Charlotte just last season! While their new head coach looks the part, its early in the season and BYU is better than most of these teams on this list. Tennessee has an awful Offensive Line (their fans have been worried all off season about it) and can't be that much better than last year's 5-7 effort.

I don't think Tennessee having home field is going to give them some sort of advantage that makes them blow us out. This game is going to be a gritty close game, and I expect BYU to pull it out in a 17-14 type victory.