MPG Observation JBD 100% vs 0%

Mark M · 08-30-2013, 07:20 AM

Heard from a friend.....

- Measured two tanks of fuel back to back from the same fuel station, tire pressures remained the same. Driving style remained the same.

1st tank of fuel:
JBD at 100%
Used AC 20%
Achieved hand calculated 32.1 mpg, on 15.28 gallons = 490 miles driven.
(OBC reported 35.6 mpg)

2nd tank of fuel:
JBD at 0%
Used AC 20%
Achieved hand calculated 34.3 mpg on 15.25 gallons = 523 miles driven.
(OBC reported 36.1 mpg)

Puerto Rican 335d · 08-30-2013, 08:42 AM

I strongly suggest you get a bigger IC for that matter and you will regain mpgs on HWY. I know I have made some mods i.e RENNtech/WAGNER IC/Air scoops and Im getting 21-23 city mpgs, its hard to get hwy mpg's since there TOO many vheicles here in the island but I once clocked over 44 mpgs at 70-75 mph at a short distance of 20 miles with A/C on. good luck on this.

crazyinp · 08-30-2013, 08:44 AM

That is strange, i have opposite issue with my OBC. It always shows less MPG than actual. I use fuelly all the time.

crazyinp · 08-30-2013, 08:48 AM

Quote:

Originally Posted by Puerto Rican 335d

I strongly suggest you get a bigger IC for that matter and you will regain mpgs on HWY. I know I have made some mods i.e RENNtech/WAGNER IC/Air scoops and Im getting 21-23 city mpgs, its hard to get hwy mpg's since there TOO many vheicles here in the island but I once clocked over 44 mpgs at 70-75 mph at a short distance of 20 miles with A/C on. good luck on this.

If the only reason to get FMIC is to gain 4MPG, you would need to drive the car for 4years before you see any savings. Simple math

Mark M · 08-30-2013, 08:51 AM

Plus I wonder how much of an affect our sooty intake charge air has on the intercooler. In theory, a new OEM intercooler would perform better than a 40k mile used OEM intercooler due to less sooty oil residue across the chambers. PR 335d, do you have any pics to show the inside of the intercooler you removed and the level of buidup within?

Puerto Rican 335d · 08-30-2013, 09:11 AM

Crazy I for one am looking for performance since MPGs here are hard to come by, Im using this as a referance for those of you in the states!!!

Mark GREAt question i still have the oem(at home) IC I will take photos of it ok and post

Thud · 08-30-2013, 09:25 AM

You really should run through 3 tanks at each setting and take an average.

2.2MPG could be within the margin of error just based on differences in driving conditions.

Hoooper · 08-30-2013, 11:29 AM

Quote:

Originally Posted by crazyinp

If the only reason to get FMIC is to gain 4MPG, you would need to drive the car for 4years before you see any savings. Simple math

def not the only reason, but certainly a benefit that is large enough to factor in to your decision

Puerto Rican 335d · 08-30-2013, 01:24 PM

Well said amigo Hooper , I bought the WAGNER IC for the power i would get and LESS heat soaking 335's in general(Gas and DIESEL models) go through. MPG's is an extra

335dFan · 08-30-2013, 01:25 PM

I hand calculate every tank. I did not notice any appreciable difference when I went from no JBD to JBD 100 pct. If anything, higher with. Today I took the JBD off for an upcoming dealer visit. We shall see. Doubt much difference will occur. On a recent road trip I was getting 39-41 mpg.

igom3 · 08-30-2013, 04:25 PM

My OBC MPG is the same as manual calculation.

Got_Diesel · 08-30-2013, 06:28 PM

I just got 38mpg hand calculated.

578 miles on 15.23 gallons of diesel. All highway from the end of new jersey to myrtle beach. Car is completely stock, sports package RFT tires too.

White D · 08-30-2013, 07:59 PM

Quote:

Originally Posted by crazyinp

That is strange, i have opposite issue with my OBC. It always shows less MPG than actual. I use fuelly all the time.

Me too. My OBC is 2-4 MPG Lower than actual.

Brad335d · 08-31-2013, 09:08 AM

My HAND calculations have always been HIGHER than the OBC. Just yesterday when I filled up, the car said 26.4 mpg, and my math said 28.x. This has never been different since I've owned the car, and its had the JBD at 100% since three weeks after I picked it up.

FormerRotor · 08-31-2013, 09:27 AM

Quote:

Originally Posted by Puerto Rican 335d

I strongly suggest you get a bigger IC for that matter and you will regain mpgs on HWY. I know I have made some mods i.e RENNtech/WAGNER IC/Air scoops and Im getting 21-23 city mpgs, its hard to get hwy mpg's since there TOO many vheicles here in the island but I once clocked over 44 mpgs at 70-75 mph at a short distance of 20 miles with A/C on. good luck on this.

FWIW I have seen no mpg changes to the positive since installing the Wagner. If you are, I would suspect it is because of your retune from RENNtech.

Re:OP...OBC is consistently about 2 mpg low for me.

taibanl · 08-31-2013, 11:40 AM

Quote:

Originally Posted by FormerRotor

Quote:

Originally Posted by Puerto Rican 335d

I strongly suggest you get a bigger IC for that matter and you will regain mpgs on HWY. I know I have made some mods i.e RENNtech/WAGNER IC/Air scoops and Im getting 21-23 city mpgs, its hard to get hwy mpg's since there TOO many vheicles here in the island but I once clocked over 44 mpgs at 70-75 mph at a short distance of 20 miles with A/C on. good luck on this.

FWIW I have seen no mpg changes to the positive since installing the Wagner. If you are, I would suspect it is because of your retune from RENNtech.

Re:OP...OBC is consistently about 2 mpg low for me.

You can adjust/correct it

zoltans4 · 08-31-2013, 04:03 PM

It all depends on driving style. Power mods can increase mpg by giving you enough power to use less pedal on a trip or less mpg because you can't stop pushing the petal to feel the power.
More importantly an IC will vary quite a bit on location. Here in Las Vegas it is very hot and dry, better IC and utilizing liquids for evap and injection (say spraying your IC or injecting meth) make a huge difference. Power can be had anywhere, but the horrible heat soak from stopping at a light or traffic can really make for bad mpg.
In the summer here in the evenings I used to drive by a golf course on the way home everyday when they were watering the dense cooler air made your car accelerate although you never pressed on the accelerator because the difference in power you were getting from the same amount of fuel being used.

zoltans4 · 08-31-2013, 04:04 PM

Quote:

Originally Posted by taibanl

You can adjust/correct it

This is also correct. If your OBC is consistently say 2mpg off every time, you simply correct it to up or down the 2mpg and it will start giving you the correct reading.

White D · 09-01-2013, 03:17 PM

Quote:

Originally Posted by zoltans4

This is also correct. If your OBC is consistently say 2mpg off every time, you simply correct it to up or down the 2mpg and it will start giving you the correct reading.

How do you do this?
Never heard of this before.

taibanl · 09-01-2013, 07:35 PM

Quote:

Originally Posted by White D

Quote:

Originally Posted by zoltans4

This is also correct. If your OBC is consistently say 2mpg off every time, you simply correct it to up or down the 2mpg and it will start giving you the correct reading.

How do you do this?
Never heard of this before.

Hidden bc menu item 20

WreckerX5d · 09-02-2013, 12:43 AM

Quote:

Originally Posted by taibanl

Hidden bc menu item 20

Never knew that existed. Mine has been off by 1mpg or so every fuel up. Thanks.

Pierre Louis · 09-02-2013, 05:18 AM

How does one correct for proper mile measurement? I used to live in areas where you could do this with special mile markers. Now all we have is GPS, so when you correct for mpg on the hidden computer screen, how does it do it? Does it "fix" the mile reading or does it fix the gallon reading or does it just make a calculation adjustment?

The reason I ask is that if the mile reading is off, so is the manual calculation.

PL

08-30-2013, 07:20 AM	#1
Mark M Major 240 Rep 1,288 Posts Drives: E30M3 E83X3 E90335D Join Date: Aug 2007 Location: Lancaster, PA iTrader: (0)	MPG Observation JBD 100% vs 0% Heard from a friend..... - Measured two tanks of fuel back to back from the same fuel station, tire pressures remained the same. Driving style remained the same. 1st tank of fuel: JBD at 100% Used AC 20% Achieved hand calculated 32.1 mpg, on 15.28 gallons = 490 miles driven. (OBC reported 35.6 mpg) 2nd tank of fuel: JBD at 0% Used AC 20% Achieved hand calculated 34.3 mpg on 15.25 gallons = 523 miles driven. (OBC reported 36.1 mpg) Last edited by Mark M; 10-25-2013 at 03:24 PM..
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08-30-2013, 08:42 AM	#2
Puerto Rican 335d Brigadier General 229 Rep 3,489 Posts Drives: Montego Blue 335d Join Date: Jun 2011 Location: Puerto Rico(Dominican Republic 03/2017) iTrader: (0)	I strongly suggest you get a bigger IC for that matter and you will regain mpgs on HWY. I know I have made some mods i.e RENNtech/WAGNER IC/Air scoops and Im getting 21-23 city mpgs, its hard to get hwy mpg's since there TOO many vheicles here in the island but I once clocked over 44 mpgs at 70-75 mph at a short distance of 20 miles with A/C on. good luck on this. __________________ RENNtech Flash(Lenny Wu)/WAGNER IC Enkei Rajin 18"/Execuhitch Hitch/Koni FSD Soft Ride Bike Rack/Brava Synthetic Motor Oil(Made in Puerto Rico)/Meth(in the works)/CBU done w Andrew EGR Race Pipe (whoa! what an animal it is now)
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08-30-2013, 08:44 AM	#3
crazyinp Major 297 Rep 1,245 Posts Drives: BMW Join Date: Jul 2011 Location: Bay Area iTrader: (5) Garage List 2022 BMW X5e [0.00] 2023 BMW X5M [0.00]	That is strange, i have opposite issue with my OBC. It always shows less MPG than actual. I use fuelly all the time.
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08-30-2013, 08:51 AM	#5
Mark M Major 240 Rep 1,288 Posts Drives: E30M3 E83X3 E90335D Join Date: Aug 2007 Location: Lancaster, PA iTrader: (0)	Plus I wonder how much of an affect our sooty intake charge air has on the intercooler. In theory, a new OEM intercooler would perform better than a 40k mile used OEM intercooler due to less sooty oil residue across the chambers. PR 335d, do you have any pics to show the inside of the intercooler you removed and the level of buidup within? Last edited by Mark M; 08-30-2013 at 09:17 AM..
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08-30-2013, 09:11 AM	#6
Puerto Rican 335d Brigadier General 229 Rep 3,489 Posts Drives: Montego Blue 335d Join Date: Jun 2011 Location: Puerto Rico(Dominican Republic 03/2017) iTrader: (0)	Crazy I for one am looking for performance since MPGs here are hard to come by, Im using this as a referance for those of you in the states!!! Mark GREAt question i still have the oem(at home) IC I will take photos of it ok and post __________________ RENNtech Flash(Lenny Wu)/WAGNER IC Enkei Rajin 18"/Execuhitch Hitch/Koni FSD Soft Ride Bike Rack/Brava Synthetic Motor Oil(Made in Puerto Rico)/Meth(in the works)/CBU done w Andrew EGR Race Pipe (whoa! what an animal it is now)
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08-30-2013, 09:25 AM	#7
Thud Throbbing Member 43 Rep 1,433 Posts Drives: Join Date: Jan 2008 iTrader: (0)	You really should run through 3 tanks at each setting and take an average. 2.2MPG could be within the margin of error just based on differences in driving conditions. __________________ 2014 Tesla Model S 85kwh Previous cars: 2011 335d / Deep Sea Blue / Saddle brown / sport / premium 2008 BMW 135i / 6MT 2002 Z06 Corvette
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08-30-2013, 01:24 PM	#9
Puerto Rican 335d Brigadier General 229 Rep 3,489 Posts Drives: Montego Blue 335d Join Date: Jun 2011 Location: Puerto Rico(Dominican Republic 03/2017) iTrader: (0)	Well said amigo Hooper , I bought the WAGNER IC for the power i would get and LESS heat soaking 335's in general(Gas and DIESEL models) go through. MPG's is an extra __________________ RENNtech Flash(Lenny Wu)/WAGNER IC Enkei Rajin 18"/Execuhitch Hitch/Koni FSD Soft Ride Bike Rack/Brava Synthetic Motor Oil(Made in Puerto Rico)/Meth(in the works)/CBU done w Andrew EGR Race Pipe (whoa! what an animal it is now)
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08-30-2013, 01:25 PM	#10
335dFan Jumping Jack Flash 321 Rep 1,692 Posts Drives: 2021 X3 M40i Join Date: Nov 2012 Location: California (east of Sacramento) iTrader: (0) Garage List 2021 BMW X3 M40i [0.00] 2017 Toyota Prius [0.00]	I hand calculate every tank. I did not notice any appreciable difference when I went from no JBD to JBD 100 pct. If anything, higher with. Today I took the JBD off for an upcoming dealer visit. We shall see. Doubt much difference will occur. On a recent road trip I was getting 39-41 mpg. __________________ 2021 X3 M40i: M Sport Differential, Adaptive M Suspension. Previous BMWs: 1971 BMW 2002, 1973 BMW R75/5, and 2011 BMW 335d Previous Other Vehicles: '67 Cougar, '70 911e, '86 Jetta Diesel, '05 and '12 Foresters, et al.
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08-30-2013, 04:25 PM	#11
igom3 Major 76 Rep 1,147 Posts Drives: 02 E46M3 15 F80 M3 16 X5 35d Join Date: Mar 2009 Location: San Diego iTrader: (1) Garage List 2016 X5 35d [0.00] 2015 BMW M3 [0.00] 2002 E46 M3 [0.00]	My OBC MPG is the same as manual calculation.
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08-30-2013, 06:28 PM	#12
Got_Diesel Second Lieutenant 20 Rep 298 Posts Drives: 335d Join Date: Dec 2012 Location: United States iTrader: (0)	I just got 38mpg hand calculated. 578 miles on 15.23 gallons of diesel. All highway from the end of new jersey to myrtle beach. Car is completely stock, sports package RFT tires too.
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08-31-2013, 09:08 AM	#14
Brad335d Oil Burner 26 Rep 231 Posts Drives: 2011 BMW 335d Join Date: Nov 2009 Location: Atlanta, GA iTrader: (0) Garage List 2014 Volvo XC60 T6 AWD [0.00] 2011 BMW 335d [0.00] 2007 Ford Shelby GT500 [0.00]	My HAND calculations have always been HIGHER than the OBC. Just yesterday when I filled up, the car said 26.4 mpg, and my math said 28.x. This has never been different since I've owned the car, and its had the JBD at 100% since three weeks after I picked it up. __________________ '11 BMW 335d Sport -JBD '07 Shelby GT500 -Not Stock
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08-31-2013, 04:03 PM	#17
zoltans4 Private First Class 7 Rep 151 Posts Drives: '14 650 coupe Join Date: Aug 2013 Location: las vegas iTrader: (0)	It all depends on driving style. Power mods can increase mpg by giving you enough power to use less pedal on a trip or less mpg because you can't stop pushing the petal to feel the power. More importantly an IC will vary quite a bit on location. Here in Las Vegas it is very hot and dry, better IC and utilizing liquids for evap and injection (say spraying your IC or injecting meth) make a huge difference. Power can be had anywhere, but the horrible heat soak from stopping at a light or traffic can really make for bad mpg. In the summer here in the evenings I used to drive by a golf course on the way home everyday when they were watering the dense cooler air made your car accelerate although you never pressed on the accelerator because the difference in power you were getting from the same amount of fuel being used.
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09-02-2013, 05:18 AM	#22
Pierre Louis Captain 158 Rep 866 Posts Drives: 2016 535d Join Date: Apr 2012 Location: Savannah GA iTrader: (0)	How does one correct for proper mile measurement? I used to live in areas where you could do this with special mile markers. Now all we have is GPS, so when you correct for mpg on the hidden computer screen, how does it do it? Does it "fix" the mile reading or does it fix the gallon reading or does it just make a calculation adjustment? The reason I ask is that if the mile reading is off, so is the manual calculation. PL
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