Does higher octane fuel burn cooler than normal fuel or is there no difference.

As far as I know my pinto head hasnt been converted. Im happy enough running in on normal pump fuel with additive as I dont do loads of miles in it.

Every so often I get my hands on some high octane (105RON) fuel for nout but dont want to use it if its going to be worse than normal fuel for the head.

For what it costs, i'd say stick with the normal fuel and additive if you are happy with it. For the mileage you do, you'd probably get away with not using any additives at all in your fuel even with the standard valve seats and 95 RON. The 98 RON fuels will allow you to run an extra couple of degrees of advance and gain a little power.

Are you using Castrol Valvemaster then???

[Edited on 25/3/09 by Paul TigerB6]

It will most likely have lead in it , sounds as if its maybe Avgas so should actually do the head good as it will help keep a coating on the valve seats.
Paul

Good point ^^^. Is it Avgas then??

105ron used to melt the exhaust valves in my old Mini. On the bright side the bits used to clean the piston tops like new. It will almost certainly be leaded so I wouldn't think twice about using it in a Pinto.

Its racing fuel, it may be slighly lower around 103ron, will have a look. But its not leaded.

Am using Castrol vavlemaster, happy to carry on using normal unleaded its just with free fuel going to waste I wanted to check if it was usable.

quote:

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Originally posted by greggors84

Am using Castrol vavlemaster

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Very high octane fuel can actually burn more slowly than lower octane, which would actually be more punishing on the valves and valve seats if the ignition timing is not optimised for it.

If you're getting this 105ron for free then mix it in with the normal stuff

Or send it this way I'll mix it in swmbo's car and watch it go!