Loss of Fuel Miles

[Karl Carrier]

Evening guys, i'm new to this site so please be kind! 

I have an S-Line A4 2008. On Friday the flashing coil light came on and went into limp mode. After turning the car off re-starting the car the light had gone out. I had a range of 255 miles left in the tank. Basically upon driving the car for every mile i did i lost 5 miles on the fuel tank. Took it in to my mechanic today, he did full service including all filters changed new oil etc, did the MOT and put it on the diagnostic machine. This threw up lots of faults. He dealt with them all, put it back on the diagnostic machine no faults coming up. I got the car back put diesel in (£60) which gave me a fuel range of 370 miles. Ive done 4 miles of driving and fuel range dropped again to 350 miles. He said he checked injectors and they seem fine, no black smoke coming out which also would suggest not injectors. 

Guys I'm at a loss so is he, anyone got any ideas?

Thank you

Edited November 2, 2022 by Karl Carrier
change year of car

[Stevey Y]

2 hours ago, Karl Carrier said:

Evening guys, i'm new to this site so please be kind! 

I have an S-Line A4 2008. On Friday the flashing coil light came on and went into limp mode. After turning the car off re-starting the car the light had gone out. I had a range of 255 miles left in the tank. Basically upon driving the car for every mile i did i lost 5 miles on the fuel tank. Took it in to my mechanic today, he did full service including all filters changed new oil etc, did the MOT and put it on the diagnostic machine. This threw up lots of faults. He dealt with them all, put it back on the diagnostic machine no faults coming up. I got the car back put diesel in (£60) which gave me a fuel range of 370 miles. Ive done 4 miles of driving and fuel range dropped again to 350 miles. He said he checked injectors and they seem fine, no black smoke coming out which also would suggest not injectors. 

Guys I'm at a loss so is he, anyone got any ideas?

Thank you

Hi you can't trust the fuel range implicitly as it works on an algorithm which makes its calculations on driving style, the most common source of milage drop rapidly is DPF regeneration. BTW £60 worth of diesel is not a lot at current prices.

Steve.

[Karl Carrier]

1 hour ago, Stevey Y said:

Hi you can't trust the fuel range implicitly as it works on an algorithm which makes its calculations on driving style, the most common source of milage drop rapidly is DPF regeneration. BTW £60 worth of diesel is not a lot at current prices.

Steve.

Hi Steve thanks for the reply. I just know the car well and know the fuel range was much more efficient prior to Fridays Limp mode saga seems odd to me why it’s dropping so much so quickly. Normally so efficient around town.