The companies give a multi-car discount that lowers the premium of each car around 20%. So when you go down to one car, that discount is removed. Factors relating to the way the company averages out the age of the drivers makes the calculation more complicated.
Your policies have uninsured-under-insured motorist coverage that protects you from drivers who hit you and cause you or your passenger injuries. For companies that offer non-stacked uninsured-under-insured coverage, both vehicles have the coverage, but they only add the charge to the first vehicle. If the vehicle is subject to state and or local taxes often they are lumped on the first vehicle as well. So when you remove a vehicle, those charges and taxes end up on the first vehicle. It gives the impression that the premium on your remaining vehicle went up, and it did because of the loss of the multi-car discount being removed, but you have to look at the uninsured-under-insured coverage and the taxes, as they play a part in the rating.
Now for companies that offer stacked uninsured-under-insured motorist coverage, this is slightly different. These companies charge you for this coverage on each vehicle you own, so when you remove a vehicle, that extra charge is also removed. You may still have the issue of the taxes being added to the remaining vehicle, but you won’t have additional premium added for uninsured / under-insured motorist coverage.
I know it is complicated and really doesn’t seem fair, but this is what will happen when you go from two vehicles to one vehicle. If you find another vehicle that you can add back to your policy, you will see that there isn’t much of a charge for adding that second vehicle. At least, that is what we have seen in the past.