(1) Does unburnt petrol igniting in the exhaust create a back pressure detrimental to the free flow of gases ?
(2) If so, is super unleaded, or Optimax even more likely to cause this ? working on an assumption that higher octane is harder to ignite, due to its increased resistance, but more powerful when it does.
(3) Again, assuming the spark is what matters in ensuring as much fuel as possible gets ignited in the cylinder, does this not then mean that the quality of the plug is more important than some indicate ? particualry where super unleaded etc is used ?
Or is it just a case that as long as the fuel is ignited, it matters not how the spark is produced or make of plug ?
Reason for the last question, is on the Regal site, it states that as part of stage 1, NGK (or equilvalent) race plugs should be used.
(4) What exactly is a race plug ?
(5) Name the best plugs to get