i have to say since replacing my dirty 200,000km CDH275's (factory 6G74 injectors) with a fresh new set of HDB305F (12 hole 6G75/380 units) fuel economy has increased from 14.5-15L/100km mixed city/very occasionally freeway,

to a staggering 10.5L/100km... granted i have only travelled 400km's CITY driving only (i can't wait to see lots of single digits for highway trips!!).. but i still am reading about half a tank.. where as before 450 would mean i need to fill up! (i hate using the fuel gauge as a guide for fuel economy, but i will post a more conclusive result once i run a few tanks through her)

also the exhaust is alot quieter, and there is a lot less resonance noise around the 1700rpm mark just when your on the converter accelerating.. the car also feels alot more responsive to very light throttle applications..

now i'm not 100% which of these it could have been.. but when i did the injectors

a few days before hand i did a Subaru upper cylinder cleaner 'treatment' which made it idle a bit smoother, and replaced the fuel filter (was only about 20 thou old anyway, but i knew i was putting the injectors in the day after)

so it could be that my injectors were really really dirty, and not atomising the fuel very well at all (which is my main conclusion as the exhaust note change indicates a better burning mixture), and or the 12 hole units are the bee's knee's for atomisation, as they have 12 tiny holes as opposed to 4 larger ones..

either way i have been struggling to get her under 14L/100 since i bought her a few years ago with 149 on the clock.. and i replaced everything (including o2 sensor) i could think of up untill the injectors just recently.. now i'm kinda kicking myself..

either way, fresh reco'd ones, with new o-rings ready to drop in and go i got for around $37 AUD each, from a guy in the US.. (our dollar is pretty good still)