The initials CSL in regards to auto insurance normally refers to combined single limit. With CSL, your auto insurer combines both Bodily Injury Liability and Property Damage Liability insurance under a single limit. The insurance company would pay up to the stated limit on a third party claim, regardless of whether the claim was for bodily injury or property damage or for both.
To the best of our knowledge when you lease a car in California, this is not always required but may be a mandate by a specific leasing company. We checked with the California Department of Insurance CSL and leased cars. Their reply was that usually, "CSL" from an insurance standpoint means Combined Single Limits, just as we mentioned early. They are not aware of this as a require with leased vehicle but that most commercial line policies provide a combined single limit for the occurrence and aggregate limits of the policy.
When financing a car, whether a lease or loan, you will normally be required to have not only the state required liability coverages on the vehicle but also physical damage coverages of collision and comprehensive. If your leasing company requires CSL then this would mean combining your liability limits instead of the normal split limits.
For example, if the limit for the CSL is $200,000 per accident, that is the total that the insurance provider will pay for all bodily injuries and property damage caused in one accident, no matter the number of people injured or what the portion of bodily injury or property damage is.
Split limit coverage splits the coverage amount into three limits, such as 15/30/5 (the minimum limits required by California car insurance law). Under the split limit coverage, these numbers would mean that you have $15,000 of bodily injury coverage per person per accident, $0,000 total for all injuries per accident and a $5,000 limit for property damage done in one accident.
The difference between a combined single limit policy and a split limit policy is that the split limit requires multiple limitations to the policy while single limit coverage gives you one amount of coverage to use as needed for the expenses resulting from an auto accident.
The split limit has the portions of payment limits already designated while the combined single limit policy can give a policyholder flexibility to use the entire coverage for bodily injury and property damage as it is needed to be allocated between the different expenses.
Therefore, if you purchase a CSL policy and are at fault in an accident you may be better covered for accidents then with a split policy. For example, say you purchase a $300,000 CSL policy and are at fault in an accident. California minimum insurance laws require that you carry 15/30/5 in liability. Now if the car you damaged costs $15,000 to repair or total out then you are already $10,000 above your split liability policy. If medical bills for the other party are high, say $40,000, due to a few people being hurt in the accident then you are another $10,000 over your limits. You thus may be personally responsible for $20,000 of claims that exceed your split limits
With a $300,000 combined singled limit (CSL) insurance policy everything should be covered in the example given above because you can to split the coverage up how you need it. Therefore, your PD liability can pay out $15,000 and your BI liability can pay out the $40,000, and you are still well below your $300,000 combined limit.
The availability of these different forms of coverage varies from insurance company to insurance company. If you have questions regarding your leasing paperwork or requirements that are placed on your leased vehicle, speak with the company with whom you have leased your vehicle for clarification.