Looking at your (@Doax) fuel log, you were averaging at 20km/L, and now you have about 26km/L. That cannot possibly be caused completely by your mod.
You were averaging 20km/L, which is 0.05L/km, which is about 0.125kWh/km (10kWh in a litre of petrol, engine efficiency about 25%). On 25km/L the car uses 0.1kWh/km. the difference is 0.025kWh/km, which is 2Ah/km at 12V.
You wrote your daily commute is about 30min, let's say 40km. In that case you should have saved 80Ah on that trip, which is 160A during that 30min. And then I'm assuming a 100% efficiency for the alternator and battery.
You also write in the log that you have mounted LRR tires. When you didn't have LRR tires before, I think they are responsible for the majority of this result.
__________________________________________
View my fuel log 2013 Space Star Cleartec Intense 1.0 manual: 55.7 mpg (US) ... 23.7 km/L ... 4.2 L/100 km ... 66.9 mpg (Imp)