What fuel for a Rangie?

[Reynard]

I have been following a discussion on an international forum on the fuel consumption and fuel type used in RR P38a's.

I thought that given the 4.0 motor was low compression it was more than happy running on regular unleaded but there's been discussion about the advantages of using premium unleaded eg 95RON or higher.

What has been the experience of those here? Better fuel consumption, increased pinging, etc etc

Reynard

[PhilipA]

Seeing that its 8.13:1 or thereabouts it will probably run on Kero without pinging. Later 4.0 litre Thor after about 2002 had a high comp engine 9.35 which needs 95 or 98.

The Yanks reckon to use high octane to get better detergents to reduce exhaust valve sticking, but I reckon over 100K that they take to stick you would probably spend more than the repair cost at 10c a litre.
I use ULP and give her a good run up a mountain . Some injector cleaner every now and then may help also.
Regard s Philip A