Ignition timing/super plus petrol

[jc denton]

OK, who here thinks its worth advancing ignition timing slightly on an older car to take advantage of higher RON petrol??

 

[Yugguy]

I can see your point but how would you calculate how much and would it really make any difference? I remember back in the 80s putting new contact breaker points in and finding TDC by rocking the car in gear to turn the crank, which is hardly accurate but never seemed to make any difference to the engine as long as I got it as near as I could.

 

[obi_waynne]

I remember those days where you could simply advance the timing. Now everything is computerised it is a lot harder unless you have the technical expertise but I'd never go back to a points/breaker set up as electronic ignition is so much better.

It does make sense to do this but how much more power will you get? I'd guess that you'd be looking at 4bhp more, and is that going to be worth the higher fuel prices?

 

[HDi fun]

Most spark ignition cars will advance to the point of detonation and then retard slightly anyway. This is done on a cylinder by cylinder basis and in real time so there's nothing to adjust really.