After lengthy testing, it seems like the average fuel consumption is about the same (13.4 mpg). However I think this is down to a combination of things:
- Most of my journeys are 80% city and 20% rush hour motorway, maybe more city driving than that.
- Given the additional temptations, my right foot may occasionally be a bit heavier. Therefore opening up the secondaries more often than needed.
I still think this carburettor is better on fuel than the old carb. I just don’t drive in conditions that best show it. On a run up to Hindhead and back, I used significantly less fuel than I was expecting to use. So cruising at 55/60 on the primaries is probably getting me the 20 mpg that I was hoping for.