Simplest lease comparison you can do is compare the following:
Lease Residual Value - Remaining Purchase Loan Balance @ Lease Term (i.e. 3 years) - (Loan Down payment - Lease Cap Cost Reduction) + $7500 Tax Credit >0
then Buying is better financially than leasing. What this formula simplifies a lot is basically, what is my equity position in the car if I buy it as your equity position in a lease is $0 at the end, so if you have positive equity in the car (i.e. what amount of money would you net if you sold it after the lease period) you come out ahead.
When I ran these numbers for my Model X and Model S comparing Teslas 3 year lease they offered me and the 0.99% financing for 72 months, I came out a huge amount ahead buying (average about $22k).
Now the risk on the residual value is all on me and if the car is not worth the end value I am using (I used the same value for the end value in the loan as the residual value in the lease calculation in the above simplification) then you will have less benefit. This is the key risk and you can adjust the above calculation by the amount you think it may be worth less than the lease residual after 3 years if you want.
Lease Residual Value - Remaining Purchase Loan Balance @ Lease Term (i.e. 3 years) - (Loan Down payment - Lease Cap Cost Reduction) + $7500 Tax Credit >0
then Buying is better financially than leasing. What this formula simplifies a lot is basically, what is my equity position in the car if I buy it as your equity position in a lease is $0 at the end, so if you have positive equity in the car (i.e. what amount of money would you net if you sold it after the lease period) you come out ahead.
When I ran these numbers for my Model X and Model S comparing Teslas 3 year lease they offered me and the 0.99% financing for 72 months, I came out a huge amount ahead buying (average about $22k).
Now the risk on the residual value is all on me and if the car is not worth the end value I am using (I used the same value for the end value in the loan as the residual value in the lease calculation in the above simplification) then you will have less benefit. This is the key risk and you can adjust the above calculation by the amount you think it may be worth less than the lease residual after 3 years if you want.