The best I ever had out of my 1.4 4spd was 38mpg and that was by sitting at 60 mph on the motorway. Having said that it always returned over 30mpg in town driving whereas the 2.0 GLS I had would dip to mid 20's in town and struggle to beat 33mpg on a run.
The later (B200 carb engined) 360's could get upper 40's if treated with kid gloves, and the 1.7's can get close too as long as the carb is in good order. 1.4's with the 5spd 'box are fairly close, but I'd say 30mpg in town and 42ish on a steady run - expect low to mid 30's in everyday use and you'd be about right.
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