<p>The point is that good grades are a necessary, but not sufficient condition for admission to most good engineering schools. Your GPA isn’t a waste - but by itself, with an ACT of 20, it’s not enough. If you had excellent test scores and lousy grades, it would be the same issue. And no, excellent ECs don’t make up for low grades or low test scores. They simply differentiate you from all the others who have both the grades and the test scores to get in (and there are many of those).</p>
<p>You can figure this out for yourself by googling the Common Data Set for each school you are interested in. Look at the latest year for which numbers are available and go to Section C, in particular, to see how you compare to the admitted student body. Note that you need to be above the lowest 25% to have a reasonable chance of admission since those with grades or test scores in the lowest 25% usually have hooks of some sort.</p>