Better Mileage with Exhaust Upgrade
01-04-2008, 06:35 AM
#1
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My Ride: 2005 BMW 545i, Silver Grey, Sport Package, R. Shades, Cold Pkg, Sat. Rad., Prem. Sound.
It's been close to 2 months now since I balanced out my exhaust system (more free flow) to accomodate for the M5 rear bumper. What I have noticed is an improvement in miles per gallon of gas. The cold weather could be a factor too but I doubt it.
Typically, I get about 60-70 miles per gas notch (4 total). That's going to work and back to home and average speed of 33.4 mph. Now, I can go to work, back to home, and to work again, and the gas meter takes only a full notch and pass it about 1 mm. I've been noticing this on the 2 remaing notches as well. My driving style has not changed. I don't trust the computer calculation because it was reading 20.1 mpg for a long time until I temporary disconnected the battery. it then said 16.7 mpg. It's wacky. Isn't the gas gauge more accurate?
Has anyone notice an improvement in mpg after intalling a more free flowing aftermarket exhaust system? Please let me know.
Typically, I get about 60-70 miles per gas notch (4 total). That's going to work and back to home and average speed of 33.4 mph. Now, I can go to work, back to home, and to work again, and the gas meter takes only a full notch and pass it about 1 mm. I've been noticing this on the 2 remaing notches as well. My driving style has not changed. I don't trust the computer calculation because it was reading 20.1 mpg for a long time until I temporary disconnected the battery. it then said 16.7 mpg. It's wacky. Isn't the gas gauge more accurate?
Has anyone notice an improvement in mpg after intalling a more free flowing aftermarket exhaust system? Please let me know.
01-04-2008, 07:35 AM
#2
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My Ride: 2011, X6 Hybrid . Alpine White , every option. 20" Conti' NON runflats,OEM trunk spoiler , LUX V3 AE's , HP Thunder Fogs , custom front bumper reflector delete........
What system did you install, I saw your pics and the car turned out great BTW.
Chers
Chers
01-04-2008, 09:37 AM
#3
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Originally Posted by Bimmer32' post='513606' date='Jan 4 2008, 07:35 AM
It's been close to 2 months now since I balanced out my exhaust system (more free flow) to accomodate for the M5 rear bumper. What I have noticed is an improvement in miles per gallon of gas. The cold weather could be a factor too but I doubt it.
Typically, I get about 60-70 miles per gas notch (4 total). That's going to work and back to home and average speed of 33.4 mph. Now, I can go to work, back to home, and to work again, and the gas meter takes only a full notch and pass it about 1 mm. I've been noticing this on the 2 remaing notches as well. My driving style has not changed. I don't trust the computer calculation because it was reading 20.1 mpg for a long time until I temporary disconnected the battery. it then said 16.7 mpg. It's wacky. Isn't the gas gauge more accurate?
Has anyone notice an improvement in mpg after intalling a more free flowing aftermarket exhaust system? Please let me know.
Typically, I get about 60-70 miles per gas notch (4 total). That's going to work and back to home and average speed of 33.4 mph. Now, I can go to work, back to home, and to work again, and the gas meter takes only a full notch and pass it about 1 mm. I've been noticing this on the 2 remaing notches as well. My driving style has not changed. I don't trust the computer calculation because it was reading 20.1 mpg for a long time until I temporary disconnected the battery. it then said 16.7 mpg. It's wacky. Isn't the gas gauge more accurate?
Has anyone notice an improvement in mpg after intalling a more free flowing aftermarket exhaust system? Please let me know.
I don't know yet. I've only had my exhaust installed for 2.5 weeks and due to the Holidays haven't been driving very much. That should change soon.
I will let you know. She sounds awesome.
Jay C
01-04-2008, 09:47 AM
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My Ride: 2007 E63 AMG | Obsidian Black | Schwarzes Nappa | Black BirdEye Maple | Premium II Package | Electronic Trunk Closer | Parktronic
Engine: RPi/Powerchips custom ECU tune, RPi Ram Air Kit (BMC filter, scoops), RennTech Sport exhaust, secondary cats, charcoal and resonator delete, custom AAA x-pipe
Exterior: 50% side windows / 35% rear window Formula One Pinnacle Series | Flat AMG hood emblem
Suspension: Renntech Lowering Module
Wheels/Tires: Radenergie R10, Falken FK452 245/30/20, Yokohama ADVAN Sport 285/25/20
-----------------------------------------
2005 545i Sport SMG | Ti Grau | Schwarzes Dakota | Anthracite Maple | Logic 7 | Nav
Engine: Custom AFE CAI, Superchips ECU remap, Sprint Booster, RDSport Dual Exhaust Conversion with Quad Pipes and X-pipe, 3 resonators deleted, 90mm tips!
Exterior: M-Tech Aero kit | M5 Mirrors | M5 Rear Bumper | Trunk Lid Finisher | Vorsteiner decklid spoiler | 50% Formula One Pinnacle Tint
Suspension and Brakes: Bilstein PSS9 coilovers, JBT BBK: 16" cross-drilled rotors, 8 piston and 15" cross-drilled rotors, 4 piston
Wheels: VIP Modular VR 02 20x9F, 20x10R | Toyo T1R 245/30/20F, 285/25/20R
Lights: PIAA 4150K Xtreme White Plus fog lights, AIB v3
MOST IMPORTANT: Hardwired V1; =)
ED Date: 4/7/05, Re-delivery date: 5/21/05
The gas mileage on the 545i got worse actually after my quad exhaust install. With the combination of the Superchips remap, AFE CAI, Sprint Booster, and RDSport quads I was always wringing it out near redline in 1st, 2nd and 3rd gear. I just loved hearing the sound of the exhaust at WOT. 
01-04-2008, 10:07 AM
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My Ride: 2005 BMW 545i, Silver Grey, Sport Package, R. Shades, Cold Pkg, Sat. Rad., Prem. Sound.
Originally Posted by westcoast550' post='513622' date='Jan 4 2008, 10:35 AM
What system did you install, I saw your pics and the car turned out great BTW.
Chers
Chers
The car still flow much better than the stock chambered mufflers. The old mufflers and pipes are quite heavy (I'll weigh time tonight along with some runflats), so maybe the weight reduction has something to do with it. I go rid of a bag of used shoes in the trunk by donating them to the Salvation Army.
Damn, those women shoes were heavy. 
no, not really. 
01-04-2008, 10:09 AM
#6
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Originally Posted by Bimmer32' post='513606' date='Jan 4 2008, 04:35 PM
Has anyone notice an improvement in mpg after intalling a more free flowing aftermarket exhaust system?
Yes, me .
The stock exhaust is a bottleneck and I'm sure that catalysts are the second one (for power and consumption) .
01-04-2008, 07:18 PM
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My Ride: 2005 BMW 545i, Silver Grey, Sport Package, R. Shades, Cold Pkg, Sat. Rad., Prem. Sound.
Originally Posted by AlexFW' post='513686' date='Jan 4 2008, 01:09 PM
Yes, me .
The stock exhaust is a bottleneck and I'm sure that catalysts are the second one (for power and consumption) .
The stock exhaust is a bottleneck and I'm sure that catalysts are the second one (for power and consumption) .
01-04-2008, 11:52 PM
#8
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Originally Posted by Bimmer32' post='513889' date='Jan 5 2008, 05:18 AM
I just weigh the stock exhaust pipe from the oe center box resonator to the tips (including muffler) and the thing weighs in around 40 ish lbs. My 2 replacement mufflers weigh about 10 lbs. max.
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