[JamesM3M5]

As far as an UPGRADE goes, there is only one way to tell. Test the Delphi coil versus the Bosch and see. For empirical testing, you would need to have a high boost car with possible misfires due to lack of spark voltage especially at higher RPMs. Run one set of coils versus another and see whether either coil sparks better with wider plug gaps.

Otherwise, just leave good enough alone. Typically these cars only need a tighter plug gap or just new coils if they are getting old once you really push the envelope.