Almost all the companies give significant discounts for engineers. Although you don't have to pick up the cheapest one, it's fair that you get the right discount from your insurance company. In this article, we will compare some of the most well-known brands.
A Reddit post talked about the Farmers' 15% insurance discount for engineers. The link in the post is invalid now. But I found it here: http://media.yellowbot.com/documents/SVj-V2ceP_o--/Special-Offers-farmers-insurance-ruth-stroup-oakland-ca.pdf The qualification for engineers is "Persons with a Bachelor, Masters, or Ph.D. in engineering. CA Engineering licensees" But the document does not mention how much actual discount you will get.
On GEICO's site: https://www.geico.com/save/discounts/organization-member/business-and-professional/#engineering You'll see a few organization that applicable for organization discounts such as Society of Manufacturing Engineers, Society of Women Engineers, etc.,
StateFarm's discount page does not list engineer specifically. However, our quote shows that engineers can receive up to 15% from StateFarm. Your insurance agents will also ask for the proof of your degree if you want to apply for this discount. https://www.statefarm.com/insurance/auto/discounts
As a tech-powered car insurance company, it's not surprising that it gives out a considerable discount for engineers. Although we failed to find documents online which indicate the actual number, based on our quote experience, engineers usually get 10% ~ 20% discount from Clearcover.
We'll keep updating this list as we complete our research for more companies. Stay tuned!