dramatically reduced mileage? Downpipe change..

clone000 · 09-13-2020, 07:52 PM

Hi Guys,

I recently changed from a catless downpipe back to my stock downpipe.

I am not sure if the shop did something or my car is adjusting back to its original downpipe etc..

I went from avg. 350-410 miles per tank to approx 280-300 miles on a full tank.

Car: 13' 528i,
intake / cat back exhaust

lsturbointeg · 09-14-2020, 03:32 PM

do you have a tune?

clone000 · 09-14-2020, 10:09 PM

Quote:

Originally Posted by lsturbointeg

do you have a tune?

Thanks for the reply

I had a JB4 and told the shop to install it, but they said it did not work when the installed it breifly, but since they attempted to install it (and intall my old DP) the car just drops in mileage.

Dash said 420 total for the tank, i ended up with 290 for the full tank.

Usually I average 370-400

Boosted M5 · 09-14-2020, 10:17 PM

I had a big jump in mpg when I went catless on my M5. A lot of tuners will advertise better gas mileage when tuning the car. Makes you wonder why it's not the opposite. I wouldn't worry about it, it's just the nature of the beast.

gr8brwnshark · 10-04-2020, 10:58 PM

Super interesting. I have the same car, '13 528i but stock downpipe with a Remus exhaust. I commute 100 miles/day for work and consistently get almost exactly 420 miles per tank. Will I get more if I put on a downpipe now? lol

09-13-2020, 07:52 PM	#1
clone000 Private First Class 10 Rep 134 Posts Drives: F10 \| N20 Join Date: Nov 2016 Location: US iTrader: (0)	dramatically reduced mileage? Downpipe change.. Hi Guys, I recently changed from a catless downpipe back to my stock downpipe. I am not sure if the shop did something or my car is adjusting back to its original downpipe etc.. I went from avg. 350-410 miles per tank to approx 280-300 miles on a full tank. Car: 13' 528i, intake / cat back exhaust __________________ 2013 M Sport 528i - HM Style Carbon Fiber Front Lip \| Dual Slat Gloss Grill w/ M colors \|H&R Front / Rear Sways \|Downpipe (Catless) \| Afe Intake
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09-14-2020, 03:32 PM	#2
lsturbointeg Lieutenant General 9153 Rep 14,522 Posts Drives: 2011 535i Jet Black Join Date: Aug 2014 Location: Asian lost in OH iTrader: (0)	do you have a tune? __________________ ~F90Conversion~21"3Piece Forged AvantGardeWheels~KWV1Coilovers~CQUENCE slotted/drilled rotors~GoodridgeStainlesslines~MeisterschaftQuadEx haust~Akrapovic 4"tips~VRSF DP~VRSF CP~TurboSmart BOV~K&N filter~CarbonFiberExteriorComponents~GladenAlphaCo mponents~MatchUp7BMW~Punch P300-12T~ Follow me on Instagram: lsturbointeg
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09-14-2020, 10:17 PM	#4
Boosted M5 Private First Class 69 Rep 193 Posts Drives: F10 m5 Join Date: Dec 2018 Location: Sf bay area iTrader: (0)	I had a big jump in mpg when I went catless on my M5. A lot of tuners will advertise better gas mileage when tuning the car. Makes you wonder why it's not the opposite. I wouldn't worry about it, it's just the nature of the beast.
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10-04-2020, 10:58 PM	#5
gr8brwnshark Private 27 Rep 81 Posts Drives: 2013 BMW 528i, 2006 BMW X5 Join Date: Apr 2020 Location: Portland, OR iTrader: (0) Garage List 2013 BMW [0.00]	Super interesting. I have the same car, '13 528i but stock downpipe with a Remus exhaust. I commute 100 miles/day for work and consistently get almost exactly 420 miles per tank. Will I get more if I put on a downpipe now? lol
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