Utah State AND Syracuse.

Spreadsheet link here:

www.goo.gl/SgxAt6

Tweet that has screenshots of the data here:

2017 CFB "Avg Player Age"
USU 23.5
Syracuse 23.5
UAz 23.3
AzSt 23.2
4 tied w/ BYU for 5th @ 23.0
--
Last Hawaii 20.0https://t.co/aRN29BxVwn pic.twitter.com/Yzg30oSrIU

— Jeffrey Fuller (@jjfuller72) July 28, 2017

https://twitter.com/jjfuller72/status/890766567046336512

And here's the top 25 oldest teams pasted in:
Utah State 23.5
Syracuse 23.5
Arizona 23.3
Arizona State 23.2
Missouri 23.0
BYU 23.0
Coastal Carolina 23.0
UCF 23.0
WKU 23.0
SMU 22.8
Eastern Michigan 22.8
Charlotte 22.8
UConn 22.7
Wyoming 22.6
UMass 22.6
Alabama 22.6
Boston College 22.6
UTEP 22.6
Stanford 22.5
Oregon 22.5
Cinci 22.5
UNC 22.5
Buffalo 22.5
Utah 22.4
Oregon St 22.4
SDSU 22.4

Here's the 4 youngest teams:
Iowa 20.7
Florida State 20.7
Kent State 20.2
Hawaii 20.0

Here's some data for BYU's schedule from the same source (with weights of OL/DL included):

Age,OL/DL Weight #s from CBSSports 4 @BYUfootball+opponents
USU has oldest team in nation (Y tied w/ 4 others @ 5th) https://t.co/9bMBQraE3f pic.twitter.com/3fQWsXeWCv

— Jeffrey Fuller (@jjfuller72) July 28, 2017

https://twitter.com/jjfuller72/status/890773586524479488

I really don't know how exactly CBS calculated this. At first I thought it might just be based on the numbers of players in each class. However, the fact that the 3 service academies and WSU don't have a reported avg age makes me think that CBSSports must be getting actual data somehow (the class/year is included for the service academies/WSU, but not an avg age tally).

I'm loving the irony of Rich Rod's comments last year about playing the BYU's old and mature players going against his team of teenagers. Pot, meet kettle.

https://www.ksl.com/?sid=41193394&nid=294&title=byu-foes-cry-foul-over-age-issue

“They’re grown men,” he said. “We’re going to have 18-year-old kids – some of our guys haven’t shaved yet — and we’re going up against some guys who got families and kids; they got to get daycare stuff. It’s going to be a different challenge for us.”

Donavan Tate, the 2009 MLB Draft's No. 3 pick, will join Arizona football as a 26-year-old freshman QB https://t.co/eAyX7SJZWu

— Arizona Sports (@AZSports) May 4, 2017

https://twitter.com/azsports/status/859981408864919552

What a doofus ...