Reduced Fuel Milage after High Flow Catted Downpipe

[mustardsupra]

Hey everyone, I recently installed my active autowerke downpipe, and it sounds and feels great! One thing I did notice is that my fuel economy has tanked, insanely. After I had some fun with it, I topped the car off and managed to burn over half the tank in around 160 KM of highway cruising. This is a lot worse than my normal numbers, and it ain’t because of my right foot hahaha! I noticed the difference and drove normally for testing purposes

I was thinking it could be the stock ecu overcompensating and running a richer mixer?
I’m getting the stage 2 tune tomorrow, will that help
Any other reasons?
TIA

Sponsored

 

[itzTang]

Hey everyone, I recently installed my active autowerke downpipe, and it sounds and feels great! One thing I did notice is that my fuel economy has tanked, insanely. After I had some fun with it, I topped the car off and managed to burn over half the tank in around 160 KM of highway cruising. This is a lot worse than my normal numbers, and it ain’t because of my right foot hahaha! I noticed the difference and drove normally for testing purposes

I was thinking it could be the stock ecu overcompensating and running a richer mixer?
I’m getting the stage 2 tune tomorrow, will that help
Any other reasons?
TIA

Normal. Proper tuning should help.

 

[BMWAF]

Hey everyone, I recently installed my active autowerke downpipe, and it sounds and feels great! One thing I did notice is that my fuel economy has tanked, insanely. After I had some fun with it, I topped the car off and managed to burn over half the tank in around 160 KM of highway cruising. This is a lot worse than my normal numbers, and it ain’t because of my right foot hahaha! I noticed the difference and drove normally for testing purposes

I was thinking it could be the stock ecu overcompensating and running a richer mixer?
I’m getting the stage 2 tune tomorrow, will that help
Any other reasons?
TIA

What are you L/100 numbers? I have a sportscat with a stage 2 MHD OTS tune and my car doesn't seem to use over 9.1/100km.. even on spirited hill climbs.

 

[djf]

What are you L/100 numbers? I have a sportscat with a stage 2 MHD OTS tune and my car doesn't seem to use over 9.1/100km.. even on spirited hill climbs.

The difference is that you’re tuned. His mileage will improve once it’s tuned

 

[mustardsupra]

The difference is that you’re tuned. His mileage will improve once it’s tuned

Yeah thanks. I will get back to you guys after the tune with the updated numbers because I’m hearing that will solve my problems

 

[BMWAF]

The difference is that you’re tuned. His mileage will improve once it’s tuned

Yeah, I know. Just providing a baseline. ?

 

[razorlab]

Stock tune targets stoich. DP ain't going to change that.

Most of the times when something like this happens is because the person is driving the car harder with their new mods.

 

[ColonelAdama]

Stock tune targets stoich. DP ain't going to change that.

Most of the times when something like this happens is because the person is driving the car harder with their new mods.

Yep if anything DP would improve mpg. Less work done by the engine to pump the turbo to the same boost targets.

 

[Funkjaw]

Any codes/CELs? Could be you boned the O2S during install, or left it unplugged.

 

[Extreme Power House]

Any codes/CELs? Could be you boned the O2S during install, or left it unplugged.

you cannot leave the O2 unplugged

this downpipe comes with a no CEL guarantee, unless its defective, you should not getting the check engine light

 

[itzTang]

you cannot leave the O2 unplugged

this downpipe comes with a no CEL guarantee, unless its defective, you should not getting the check engine light

huh!? how would you know the OP plugged or not plugged the o2?

 

[mustardsupra]

Stock tune targets stoich. DP ain't going to change that.

Most of the times when something like this happens is because the person is driving the car harder with their new mods.

I'm gonna get back to you after I tune it with an update. I was driving it and cruising at mostly highway speeds, was not driving it harder.

 

[mustardsupra]

Yep if anything DP would improve mpg. Less work done by the engine to pump the turbo to the same boost targets.

Yes that is exactly what I was thinking... I'm entirely certain mpg has decreased. I was driving the exact same way as before and milage has dropped. Next time im at my car, I'll get you accurate mpg numbers.

 

[mustardsupra]

Any codes/CELs? Could be you boned the O2S during install, or left it unplugged.

No codes, everything was plugged in properly

 

[razorlab]

Yes that is exactly what I was thinking... I'm entirely certain mpg has decreased. I was driving the exact same way as before and milage has dropped. Next time im at my car, I'll get you accurate mpg numbers.

How are you calculating MPG? The real time MPG on the dash or actually doing the math?

Only accurate way is doing the math. Miles Driven ÷ Gallons Used = MPG

Sponsored