How critical is PREMIUM fuel for Q45?

[pperelman]

Just want to know what might happen. I have owned LandRover which required Premium "only". Had it filled with mid range fuel - ok no problem...slightly less accelleration. No major engine problems have been discovered.
TIA
Pit...

[maxnix]

Very. The KS will start retardation which will increase richness, decrease mileage, and may start a runaway overheating condition on less than new OEM spec cooling systems.

The O2 sensors and catalytic converter's life will be shortened.

Don't confuse a DOHC VH45DE with a Landrover pushrod V8 from the sixties. If you must buy regular, get a Honda or a later model Cadillac.

[pperelman]

I know all aspects of ign syst and engine controls Just wanted to hear from real owners of this elegant vehicle!