Good point from @cptofthehouse. When you visit schools, ask about the 1st year retention rate for engineers (ie, how many switch majors after the first year), which usually correlates with the graduation rate (and yes, 5 years is nearly typical for engineers anymore, though usually because of work placements or class availability).
And when he goes, don’t ‘place out’ of the first level Calculus group. Collegekid had the choice, and chose to take the first level Calc course & says it was one of the best decisions she made. Even with AP Calc the class wasn’t easy- and it is so fundamental to the rest of the course that having a strong base was worth it. And, not struggling right from the start helped her confidence during that first term adjustment to college.