1. The issue of less reliability with the high component count verses the original relay
hasn't been discussed, i.e. the reliability decreases as the component count of any
system increases.
2. A solid state fuel pump relay is less reliable and prone to failure when the fuel
pump stalls or may generate excessive start-up currents than a mechanical relay.
3. Most all automotive OEMs still use mechanical (contact type) fuel pump relays.
4. The inductive discharge voltage when the fuel pump turns off can over-stress
solid state switching devices.
5. Solid state relays are more prone to failure during an intermittent over-charging
alternator.