well I am looking at fuel saving kits for my 4 year old myvi icon 1.5SE, currently its doing 13km per litre on 60 city 40 highway
And one of my trusted workshop suggested these, with tm works direct power harness, and supercircuit extractor
(+ I prefer not to turn my car into road bully with loud exhaust) haha.
I don't quite agree with the VS. I have not felt any difference with Inazma during the days I tested it. I've only ever had 2 types of VS that had some sort of effect. One was a DIY-ed one that used quite a lot of expensive parts (cost was RM130) and experimented by a electronics guy. It had some sort of affect on the pickup of the car which was interesting. Didn't improve anything else. The other VS was quite an old one that is no longer in production - it made the battery last 4 years and seemed to smooth out electronics (the lights dimmed less whenever the aircon compressor kicked in).
You want to improve FC the TM Works thing is going to smoothen out your plug coils and perhaps give a bit of extra torque. But the caveat is if your car is old - then it'll work great to make it "new again". A new car won't feel any difference. If you however increase the voltage output using stuff like the IgniteVSD and Alpha16V it'll probably help a bit with the spark side of things and improve combustion hence improving FC? I dunno. I wanna test this but it's not exactly cheap.
Then the extractor - yes and no. Depends. I dunno.
Aiya..if you want to improve FC there's loads you can do. Keep your car engine and everything in tip-top condition, use good oil, use good petrol, improve your spark everything, let engine breathe better (free flowing drop-in air filter, don't use open pod), lightweight rims and low-resistance tyres, plexiglass windows and stripped interior, stop using air-con and lighten the car, etc etc. It'll probably cost you more to save petrol than just driving with a brick behind your pedal.
Incidentally that last one is real - driving with the air-con off makes a huge difference. I have a 1st gen Myvi with a busted aircon compressor so I drive without aircon. Just open window and drive - and drive conservatively. I got 16.7km/L recently.