Percolation? Heat soak? Don't drive during summer??

I definitely agree 230 is pushing it. I would be flushing the coolant system and checking the condition of the thermostat. I think the thought of heat breaking down viscosity is a valid point, I am just not sure. I agree with Jpar too, I wouldn't be scare to see 160-170. The oil is still going to have heat in it, and I would think enough heat to burn any condensate out of it.