Test optional colleges typically admit a good portion of the class test optional, but few colleges provide stats that break down specifically to engineering, so stats are often not available for engineering students. When stats are available, they typically show a good portion of engineering students are admitted test optional, like the college as a whole.
For example, Cornell is generally considered to have the top engineering program among Ivy League colleges. ~40% of admits to Cornell Engineering have been test optional in 2021-23 compared to ~50% for A&S. However, it’s also important to note, the Cornell test optional review found the following.
Regression models that estimate the probability of admission holding constant several other factors—including high school GPA and additional student and high school characteristics—suggest that submitting test scores significantly increases the likelihood of admission in the test optional colleges but has little or no effect in the score free colleges.