A return on equity that continues to exceed that of its insurance owner by a mile and a near zero level of loan impairments cast a new light on Suncorp Bank.The ROE for the bank was 13 per cent over the year to June 2017 up from 12 per cent in 2016, Suncorp disclosed in its annual results.At the group level, the ROE was 8.2 per cent on a cash basis.Suncorp Bank's part in ratchetting up lending rates on investment loans this year has not aided the net interest margin. This fell 3 bps to 1.83 per cent.Problems with an IT upgrade for its Oracle systems are one obstacle for the bank.Implemented last financial year, this kit "has taken longer than expected to fully embed and adapt for use in the Australian market," Suncorp said.The aim now is to "complete the final migration phase for remaining retail loans at which point it will pause the migration of deposits and transaction banking products, pending further system enhancements from the vendor."The banking business net profit of A$396 million was only $3 million better than in 2016. Lending growth of less than two per cent was below system.Investor lending growth of four per cent was, Suncorp noted "well within the supervisory measure of ten per cent."The bank trimmed its share of interest-only loans to 28 per cent, inside APRA's new cap.Issues with credit quality at Suncorp Bank are for the future, the ratio of impairment losses to gross loans all of 0.01 per cent, one third the level of 2016.The ratio of net impaired loans to gross loans for the bank was 0.23 per cent.