Epic gas guzzling after stage 2 BM3

GrabEmByTheBimmer · 03-06-2023, 10:26 PM

2015 335i. Recently jumped from BM3 stage 1 93 octane w upgraded charge pipe to BM3 stage 2 93 octane FBO (high flow catted downpipe). I’ve probably driven 100 miles on it. The tune is phenomenal - burbles sound louder (I have the non aggro tune bc I have a cat), turbo spool is def louder, and performance is impressive.

Only thing is, the gas usage seems to have literally doubled. My first night testing the tune I went through 1/2 tank on one drive! That said, I was going WOT a lot. I’ve continued to see the same gas guzzlage on subsequent drives. It drains like an old iPhone battery, gives me Tesla battery anxiety but for my BMW. I’ll update soon w mpg, I haven’t taken a reading. Is this all par for the course? Anything you guys have done to mitigate this? Ill probably be running 100% economy mode unless I want to have fun - and I can count on one hand the times I’ve used it prior.

Nickski06 · 03-07-2023, 07:29 AM

Yes, more horses will eat more hay. That being said, it’s probably 90% because of how you’re driving it now. When I jumped to stage 2 MHD on my 340, my average mileage dropped about 3 mpg. However, on a long trip, my highway mileage hasn’t really changed. So in conclusion, with the extra noise and power you get with stage 2, you’re mileage is mostly because you’re on the throttle more than normal, thus killing your mileage.

GrabEmByTheBimmer · 03-07-2023, 01:56 PM

Quote:

Originally Posted by Nickski06

Yes, more horses will eat more hay.

My new favorite quote, I’m stealing this!

thejeremyman9 · 03-07-2023, 03:58 PM

The tune doesnt change AFRs or anything at low/light throttle, so as noted above, its your driving style. Because of the increased HP/boost targets/etc, you will command more boost (and thus more fuel) for a given pedal input. So even if your right foot is doing the same thing as before, 30% pedal input will be using more fuel with a stage 2 tune than a stage 1 tune. In order to keep fuel economy the same, you actually need to reduce pedal input, to keep the acceleration what it was before.

Gen13 F36 · 03-07-2023, 07:27 PM

No shit!!!, you pay to play

03-06-2023, 10:26 PM	#1
GrabEmByTheBimmer Private 18 Rep 89 Posts Drives: F30 Join Date: Sep 2018 Location: USA iTrader: (0)	2015 335i. Recently jumped from BM3 stage 1 93 octane w upgraded charge pipe to BM3 stage 2 93 octane FBO (high flow catted downpipe). I’ve probably driven 100 miles on it. The tune is phenomenal - burbles sound louder (I have the non aggro tune bc I have a cat), turbo spool is def louder, and performance is impressive. Only thing is, the gas usage seems to have literally doubled. My first night testing the tune I went through 1/2 tank on one drive! That said, I was going WOT a lot. I’ve continued to see the same gas guzzlage on subsequent drives. It drains like an old iPhone battery, gives me Tesla battery anxiety but for my BMW. I’ll update soon w mpg, I haven’t taken a reading. Is this all par for the course? Anything you guys have done to mitigate this? Ill probably be running 100% economy mode unless I want to have fun - and I can count on one hand the times I’ve used it prior.
	Appreciate 0 Tweet Quote

03-07-2023, 07:29 AM	#2
Nickski06 Private First Class 53 Rep 106 Posts Drives: 2016 340i M-Sport Join Date: Sep 2020 Location: Indiana iTrader: (0)	Yes, more horses will eat more hay. That being said, it’s probably 90% because of how you’re driving it now. When I jumped to stage 2 MHD on my 340, my average mileage dropped about 3 mpg. However, on a long trip, my highway mileage hasn’t really changed. So in conclusion, with the extra noise and power you get with stage 2, you’re mileage is mostly because you’re on the throttle more than normal, thus killing your mileage.
	Appreciate 2 GrabEmByTheBimmer18.00 oem.plus_440gc366.50 Quote

03-07-2023, 03:58 PM	#4
thejeremyman9 Major General 4392 Rep 7,632 Posts Drives: 2015 BMW 335i Join Date: May 2019 Location: Cali iTrader: (0)	The tune doesnt change AFRs or anything at low/light throttle, so as noted above, its your driving style. Because of the increased HP/boost targets/etc, you will command more boost (and thus more fuel) for a given pedal input. So even if your right foot is doing the same thing as before, 30% pedal input will be using more fuel with a stage 2 tune than a stage 1 tune. In order to keep fuel economy the same, you actually need to reduce pedal input, to keep the acceleration what it was before.
	Appreciate 1 GrabEmByTheBimmer18.00 Quote

03-07-2023, 07:27 PM	#5
Gen13 F36 Brigadier General 1599 Rep 3,748 Posts Drives: 428i Gran Coupe Join Date: Nov 2017 Location: Los Angeles, CA iTrader: (1)	No shit!!!, you pay to play
	Appreciate 1 GrabEmByTheBimmer18.00 Quote