Sudden milage drop


Hello i have a audi a4 2.0t and i am experiencing a sudden milage drop in my car in city i go only around 3-4 km and the on board km thing drops by 10km but on it drop by 10km after 13-14 km i am only having this problem in city anyone know what’s wrong?

Probably nothing. When you start the car, the computer uses its last mpg which was on a warm engine. Short trips in the city use much more gas.

What year?
How many kilometers are on the odometer?
Has it been well maintained?

City driving is horrible on mileage. That may well be the only problem.

I notice something similar on my 2017 Accord with the 4-cyl. I’ve seen less than 20 mpg when I first start the car and drive slowly to a highway. As I put on miles at 55+ mph, it climbs to bet than 33 mpg, and often the instantaneous mileage is around 39 mpg.

Are you referring to the km/gallon (fuel usage) reading, or just the km (distance travelled) display?

In city it just goes like 2-3km per letter but on highway it goes 13-14km this started happening after I got my diverter valve changed

With respect, I can’t understand the post.
What “diverter valve” are you referring to?

I think he might be referring to a blowoff valve:

@Gurkamal_Singh Did you just have your turbo repaired? If it wasn’t working before but it is now (and you’ve been a little heavier footed on the gas pedal), I could see that causing a milage drop

I think you might be right.
And the conclusion in your post might also have merit.

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I presume you mean per liter. If a decrease in km per liter is your primary concern, the most common cause Iis a malfunctioning cooling system thermostat. If the engine is running below its optimally designed for operating temperature, the km/liter result will suffer. That’s the first thing to check.

Check these components and REPLACE. Check the air filter, change pcv valve and change the oil.