Supplementary fans

[Minxy]

Hmmm don't know what the others think but the negligent rise in temperature from the different fuels should have little or no effect overall. In my experience electric fans where seldom if ever used in a supplementary way but were used where extra cooling was required due to modifications often when fixed fans where removed to free up power or engines were retro-fitted to cars that did not allow the rad to be sited in front of the water pump.

[JPB]

.......electric fans where seldom if ever used in a supplementary way but were used where extra cooling was required due to modifications often when fixed fans where removed to free up power or engines were retro-fitted to cars that did not allow the rad to be sited in front of the water pump.

Late model VW Passat TDIs have an engine-driven viscous fan and an electric one alongside, then VW turned the engine around and ruined that great idea.

And with ignition timing set correctly and using fuel of the correct octane rating you'd never notice the difference in running temperature on the gauge. 848cc miniMetro vans (a Swedish thing, no idea why) ran on the old 2 star (typically 92RON in the UK) which was way below current Premium (95RON) or Super (97-99RON) petrol in octane rating yet the CR on the 850 was around 9.7:1 (Source: Autodata 1981-1991, ISBN 0-85666-601-7) so roughly the same as the E in Allegro 1.5 sc form.

[Richard Moss]

My money is on a partially blocked radiator or thermostat which isn't opening fully or (less likely) a "slow" fan.