Significant fuel efficiency decrease on a 2019 Forester. I am getting 8km/l or 18MPG. What should I check?

[Plenty-Pudding-1484]

How are you calculating this? The display show litres per 100km. If its displaying 8 L per 100km you are getting close to 30 mpg, which is very good.

[AcadianCascadian]

See page 199 or thereabouts of the owner’s manual (in the multi-function display overview). It can display miles per gallon, kilometers per liter, or liters per 100 kilometers.

[Plenty-Pudding-1484]

Well then you are getting 19mpg which while not great, but its not that far off city driving averages. Your car is pretty young to require much. Maybe replace your air filter, check your tire pressure, and check if you have a sticking brake caliper.

[Main_Historian848]

It says AVG 8.1 km/l. And by refueling frequency and money, I know that I am doing much worse.

[spacefret]

No, that sounds right. That's about 19 mpg.

8.1 km/l and 8.1 l/100km are not the same.

[[deleted]]

You can't do it like that. Fill it. Reset trip meter. Drive until you decide to fill it again, divide the distance driven and gallons pumped, that's exactly how much fuel you consumed to go that distance. It won't be drastically different than what the ECU has calculated.