3.5 carb vs 3.9i mpg

Much difference?

3.9i will has a smoother torque curve and has slightly more torque at the bottom end.

I would go EFi every time. Carbs are just soooo 1980s

why? There is when ones got an LPG conversion...

I may be mistaken but I think the introduction of efi was to improve driveability and power as well as improve economy and lower emissions. For what it is worth, my 3.9RRC returned an average of 17mpg over 650 miles of mixed driving comprising motorway, traffic jams, urban crawl, minor roads and laning.

My old man's 83' 3.5 twin carb Rangie would do about 8mpg....however it was driven.

i would say that the efi must be more efficient but no idea on the figures.. probably out there on a web search if you look..

My old 1977 carb Rangie from years ago would average about 13mpg combined driving. Dropped to 11mpg in town & gave 18mpg tops on motorway. Car was well tuned & drove well. One reason why I've never bought another Rangie, though I've been tempted a couple of times. Another minus with the carbs was mine were fitted with the infamous poppet valves on the butterfly discs which had the notorious weak springs resulting in the revs shooting up sometimes. Had to solder mine permanently shut, then all was ok. Also had to keep the carbs balanced & had to sort out some bodged linkage mechanism. once sorted, they were reliable. Apparently swapping the Zeniths for SU's was a popular move & could give you an extra mpg or so.