There is one thing I am curious about and I never see anyone talk about this when a country goes mostly EV. What impact if any is there to the cost of diesel f

There is one thing I am curious about and I never see anyone talk about this when a country goes mostly EV. What impact if any is there to the cost of diesel fuel? There are still big trucks, farm equipment and construction equipment that needs fuel. That equipment is not going to change to EV as fast as cars. Has the cost of fuel risen notably when demand from consumer cars drops? I am asking because I am looking at excavators and skid steers. There are a handful of EV excavators but they are exponentially more expensive right now. If I were a business, it might pay for itself but I am buying them for myself.