well after chemo treatment we headed up to Oregon coast, Bandon. came up i5 over mountains. wow, long haul up. outside temp was 105-110 new 2015 Ram 3500 diesel 2001 30ft Cardinal 12,100 ...
Nothing wrong at all with those temps. Your Cummins has an oil cooler (oil to water) and with those temps, AC running, pulling a load, those are normal.