Back on the day 25 thou or 0.6mm was standard plug gap and old style NGK 14mm plugs still come pre-set to this. Nowadays with modern individual coil packs they seem to have crept up to 35 thou or around 0.8mm. Since the gap will increase if anything with age (particularly with fine tip plugs) I still aim for the lower end if in doubt.
Thanks for that Richard; it confirms my original thoughts. Would have thought the 1.25mm figures would be more akin to a race spec engine possibly.
