Disco 3 or RR tdv8?

[openspaceman]

This diesel vs petrol thing is not rocket science. Modern diesels running under full throttle use roughly the same air fuel ratio as a petrol at around 14.1 , the biggest difference is at idle or low revs when the petrol is still running roughly 14.1 air fuel ratio but the diesel can be as low as 150.1 . A diesel can be in stop start traffic for hours and use virtually no fuel whereas the petrol will drink gallons of the stuff. This is why folk with a light foot that dont rev the granny out of an engine can get these mpg figures. GM v8 6.2 diesel at idle has a fuel consumption of a third of a gallon an hour, see how long a third of a gallon will last in a v8 petrol at idle.

 

Bob

 

I don't think na diesels get near stoich and run weak of 20:1. The reason diesel's part throttle economy is better is that the volumetric efficiency is always 100% or more.I'd be interested to know if turbo diesels can approach stoich. Also of course diesel has 10% more calories per litre which propel them a bit further.

[skyhuck]

During my recent Landrover experience the fuel was the cheap bit