a dealer offers to sell a truck for $230,000 with a 3 year financing at 1.5% (3 equal payments) and the market rate is 6%

Another dealer offers to sell a truck for $208,000 but financing needs to be done through the bank at 6% (4 equal payments)

I am having a hard time understanding how the 1.5% is supposed to affect the lease payment schedule, and how this is different/similar than calculating the present value of a bond.