CheeseHelmet
Member
Found out yesterday that the light comes on (then turns off if I turn) almost right at 12 gallons.
Mine comes on around 8-10 liters (roughly 2.0-2.5 gallons).
One thing that made a huge difference for me was changing my rear O2 sensor; it was broken and I got about 400km (~250mi) on a tank. This morning my needle was at the halfway mark and the trip odometer was reading 270km (~168mi).
It's probably a waste of money to change your O2 sensors prematurely, but if the check engine light comes on and that's the problem, it's worth the money to change it just for the added fuel economy.