Gap insurance covers the excess amount on your auto loan in an instance where your insurance company does not cover the entire loan. Depending on the company's specific policies it might or might not cover the deductible as well. This coverage is marketed for those who put low down payments, have high interest rates on their loans, and those with 60-month or longer terms. Gap insurance is typically offered by a finance company when the vehicle owner purchases their vehicle, but many auto insurance companies offer this coverage to consumers as well.
The cheapest car insurance, period, will likely carry the minimum coverage required in your state. In most states, this is liability insurance only, which covers property damage and medical bills for others due to accidents you cause. Some states also require uninsured and underinsured motorist coverage, which pay for your injuries or damage if an at-fault driver doesn’t have enough insurance.