Ok so I recently bought a f350 6.7L Crew cab 95k miles on it, my question is when I tow my 2014 Springdale 32ft tow trailer weight about 11k lbs loaded my engine oil temp hit 260F when going up hill, I feel I still have a lot of peddle left and only going about 55-60 mph, is this temp normal? I've called 3 dealership and they all have said to keep it under 290F and I would be fine.