Adding a vehicle will definitely make your insurance (total bill). Let's for argument sake say you are paying $1,000 for insurance. You add a second car, which for the example assume is the same car with the same coverage, so it would also be $1,000 making the toal bill $2,000. The multi-car discount takes 5% off each car, so now instead of costing $1,000, its $950 per vehicle, so the total bill is now $1,900 instead of $2,000. You saved $50 on your existing premium but added $900 to your total cost. This is the same even if the coverage on the second vehicle is lower than the first car. It will definitely increase your out of pocket cost. My advise if you can do without the second car don't add one. It will save you a bunch of money if you're trying to save. I did this with my wife for about 5 years when we were first starting out. Sometime a PIA without a second vehicle, but it definitely helped us out financially. Good luck.