Installment util% calculations do exist but they carry less weight than revolving utl% calculations. Your difference in scores might simply be the difference between the three scoring models. FICO EQ, EX and TU while all FICO are still different scoring models. Also, you, pizza and I all might be swimming in different "pools, scorecards or buckets."
installments do not count towards utilization, but they do count as accounts with balances, and if you have too many, it hurts your score--I'm positive of this now
my ex and eq profiles are virtually identical--except for ex shows 6 accounts with balances and eq shows 4 accounts with balances.
6 accounts with balances on ex = 704
4 accounts with balances on eq = 726
I'm telling you, it means something. Keep 4 or less and your score goes up.