Hi all, happy to report I'm back in a civic (mk10), bought a 2018 1.6 diesel with 40k on the clock (2018 plate). This is after having a mk9 with the same engine (2014 plate) all be it with a gap (went 'posh' and had a v90 for 18 months, spoiler alert, the honda is more reliable), both effectively same engine, same manual box etc.
Anyway, I do faily mega milage (30k a year at least) and I'm 10k in from when I bought the car in late December. When I bought it almost immediately I had an issue with an engine light which ended up being 1st lambda sensor (replaced by honda). Prior to the 'fix' I was really struggling to hit 50mpg but put this down to being understandable. Since the fix the mpg has improved, however I'm struggling to get more than high 50s. I've got it into low 60s on a proper eco drive of say 30 mile or so, but never getting anywhere past mid 60s, but really REALLY trying.
I should point out that my driving (by nature of the miles I do) is mainly national speed limit roads cruising at 60 the majority of the time, and motorways sitting in the mid 70s of cruise. I have tried not using cruise, tried turning eco off, and back on for good distances and with basically zero effect.
I drive the same roads as I did in the mk9 and regularly was hitting 70mpg, often mids and over long distances.
Is this normal? I appreciate it may be a bit worse than the mk9 with weight etc but didn't expect such a big difference (I would say 15mgp average worse). My concern is that there's another fault or issue that caused the lambda to fail that's still in the background. Car drives fine etc. Could this be where someone has put petrol in it or something?? And comments/suggestion etc much welcomed ta