Hi; I have done some research and the mirage looks to be one of the most efficient ‘normal’ petrol cars out there at the moment which is also affordable.
I want to then maximise fuel savings further by converting it to LPG [also known as CNG] as it is fairly common to source and is only about half the price of petrol in the UK.
However; I don’t know if it would be recommended with its engine and wondered if there is any knowledge here about it?
Certain engines such as those on German cars usually don’t have issues with it but I have heard Japanese engines or those on cheaper models have components made from softer metal.
The effect of running long-term on LPG is similar to when old cars started running on unleaded fuel in that the lack of lubrication results in pre-mature valve seat and guide wear.
There are kits that deliver an additive along with the natural gas as you drive along using a vacuum driven drip-feed system but this doesn’t work under light-load steady-throttle situations such as when cruising on a motorway and it is really only optimised for stop-start city driving.
I do about 4 miles of city driving at the beginning and end of my journey with about 20 miles of flat motorway in-between twice-daily.
The conversion usually allows the engine to start and run the first few minutes on petrol until it is warmed up and then switches over to the natural gas but also usually offers a manual switch when the secondary tank is empty.
Is there any data that might suggest if the valves on the Mitsubishi engines are hardened and would resist this wear?