340xi mpg drop- need advice

JimBean2014 · 12-20-2018, 01:23 AM

Hi friends-

Back in VA my gas light would come up around 300-320 mi range but that has changed a lot in the recent months after my move to CA.. now it does so in the 230-250 mi range..

I am not sure of reasons for this big drop except may be VA has 93 octane and in CA I'm getting 91..traffic conditions are more or less the same..I also checked the tire pressure and it is normal (32 front/34-35 rear tires as per the sticker)

Would really appreciate to know your thoughts. Thanks

jparnes1 · 12-20-2018, 09:31 AM

91 is approved for BMWs so it's not the gas. Different driving habits: are you in the street more than before? More stop and go on the highway?

JimBean2014 · 12-20-2018, 09:50 AM

Quote:

Originally Posted by jparnes1

91 is approved for BMWs so it's not the gas. Different driving habits: are you in the street more than before? More stop and go on the highway?

Thanks .Traffic conditions are almost the same and my driving habits haven't changed much..taking in for service tomorrow,will ask about this and see

Mkswoosh · 12-20-2018, 11:48 AM

Elavations has an affect on mpg as well. More than you would think. Not sure the difference from Ca and Va though

But itll never hurt to change oil and air filter and such.

JimBean2014 · 12-20-2018, 12:55 PM

Quote:

Originally Posted by Mkswoosh

Elavations has an affect on mpg as well. More than you would think. Not sure the difference from Ca and Va though

But itll never hurt to change oil and air filter and such.

Thanks,that makes sense

truth649 · 12-20-2018, 04:22 PM

Is there a difference in temperature? I always get better mileage in warm weather than cold.

jh_f30 · 12-20-2018, 04:36 PM

Quote:

Originally Posted by truth649

Is there a difference in temperature? I always get better mileage in warm weather than cold.

Between Virginia and San Diego? I would say so!

I've actually been noticing a similar trend with my car. No location changes, but I did go from a long highway commute to mostly city driving.

Might also be an O2 sensor going out. I read that a faulty sensor can cause decreased gas mileage.

KRS_SN · 12-20-2018, 05:56 PM

this is ominous. i am no expert but mt car did this(mpg dropped from 30's to 20's and after a few weeks it broke down l. for some reason your fuel isnt being efficiently burnt. take it to the dealer.

Wires · 12-20-2018, 07:30 PM

Does CA get "winter fuel" like us up north? We experience a substantial mileage loss when the fuel gets swapped over (which would be similar to what you are seeing).

gizmo32 · 12-20-2018, 08:04 PM

my mileage in winter goes from 600km plus (summer) to around 480-530 km a tank

JimBean2014 · 12-20-2018, 08:17 PM

Quote:

Originally Posted by Wires

Does CA get "winter fuel" like us up north? We experience a substantial mileage loss when the fuel gets swapped over (which would be similar to what you are seeing).

I have never heard of this winter fuel thing,will do some research about it..San Diego doesn't have winters like NE ..it is constant 70s and sunny on most days

gds52 · 12-20-2018, 08:31 PM

Where have you been filling up.
Not sure if you know Wawa gas stations in East.....worst gas ever. My 3 cars' mileage dropped like crazy....then I searched and people were calling out Wawa gas the worst. Some ppl had their cars' fuel pump replaced.
I wrote to Wawa...the said if you have any repair send us the bill...lol.
Make sure to get good gas.....look for Top Tier

JimBean2014 · 12-20-2018, 08:49 PM

Quote:

Originally Posted by gds52

Where have you been filling up.
Not sure if you know Wawa gas stations in East.....worst gas ever. My 3 cars' mileage dropped like crazy....then I searched and people were calling out Wawa gas the worst. Some ppl had their cars' fuel pump replaced.
I wrote to Wawa...the said if you have any repair send us the bill...lol.
Make sure to get good gas.....look for Top Tier

I used to fill up at Texaco/shell/Costco in VA and now Valero/Shell in CA

gds52 · 12-20-2018, 09:32 PM

Quote:

Originally Posted by JimBean2014

Quote:

Originally Posted by gds52

Where have you been filling up.
Not sure if you know Wawa gas stations in East.....worst gas ever. My 3 cars' mileage dropped like crazy....then I searched and people were calling out Wawa gas the worst. Some ppl had their cars' fuel pump replaced.
I wrote to Wawa...the said if you have any repair send us the bill...lol.
Make sure to get good gas.....look for Top Tier

I used to fill up at Texaco/shell/Costco in VA and now Valero/Shell in CA

Try changing the gas company and make sure it's top tier gas. Some gas stations were caught in Jersey selling non premium gas under premium

agentorange · 12-21-2018, 10:11 AM

IIRC winter gas in CA (if not all gas) has about 10% ethanol. That doesn't do your mileage any favors.

jh_f30 · 12-21-2018, 12:18 PM

Quote:

Originally Posted by agentorange

IIRC winter gas in CA (if not all gas) has about 10% ethanol. That doesn't do your mileage any favors.

Nearly all CA gas is E10. At least up here in the Bay Area. Also, we do get different formulations between winter and summer.
https://www.caranddriver.com/news/a1...ine-explained/

JimBean2014 · 12-27-2018, 12:06 AM

Update: Just got the oil change done with the dealer and they couldn't verify the mpg drop.. however, they mentioned my car has Dinan piggyback.I know my car has MPPSK but didn't know about Dinan. Will someone be able to confirm from the pic?

12-20-2018, 01:23 AM	#1
JimBean2014 Second Lieutenant 44 Rep 275 Posts Drives: 2020 X3 M40I Join Date: Sep 2014 Location: San Diego CA iTrader: (0)	340xi mpg drop- need advice Hi friends- Back in VA my gas light would come up around 300-320 mi range but that has changed a lot in the recent months after my move to CA.. now it does so in the 230-250 mi range.. I am not sure of reasons for this big drop except may be VA has 93 octane and in CA I'm getting 91..traffic conditions are more or less the same..I also checked the tire pressure and it is normal (32 front/34-35 rear tires as per the sticker) Would really appreciate to know your thoughts. Thanks
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12-20-2018, 09:31 AM	#2
jparnes1 Colonel 245 Rep 2,387 Posts Drives: 2016 340i, 2012 Z4 35i Join Date: Jan 2010 Location: NY iTrader: (1)	91 is approved for BMWs so it's not the gas. Different driving habits: are you in the street more than before? More stop and go on the highway? __________________ 2016 340i XDrive, EBII/black, 6 MT, M Sport, Track Handling, Cold Weather, Tech, Lighting, Driver Assistance Plus. 2012 Z4 35i, ED 2/24/2012, Melbourne Red Metallic, Black Leather, Carbon Trim, 6MT, M Sport, CW, PP, PS, NAV, CA.
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12-20-2018, 11:48 AM	#4
Mkswoosh First Lieutenant 93 Rep 385 Posts Drives: 2018 340xi tanzanite blue Join Date: Nov 2018 Location: Portland iTrader: (0) Garage List 2018 BMW 340xi [0.00] 2021 Ford Bronco Ba ... [0.00] 2015 Kawasaki Ninja ... [0.00]	Elavations has an affect on mpg as well. More than you would think. Not sure the difference from Ca and Va though But itll never hurt to change oil and air filter and such.
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12-20-2018, 04:22 PM	#6
truth649 Enlisted Member 14 Rep 49 Posts Drives: 2016 BMW 340i xdrive Join Date: Oct 2016 Location: Bristol CT iTrader: (0)	Is there a difference in temperature? I always get better mileage in warm weather than cold.
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12-20-2018, 05:56 PM	#8
KRS_SN Major General 13530 Rep 5,210 Posts Drives: IX,G07 Join Date: Oct 2018 Location: Glasgow iTrader: (0) Garage List 2020 X7 [10.00] X5 [8.50] IX [8.00]	this is ominous. i am no expert but mt car did this(mpg dropped from 30's to 20's and after a few weeks it broke down l. for some reason your fuel isnt being efficiently burnt. take it to the dealer.
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12-20-2018, 07:30 PM	#9
Wires Brigadier General 1646 Rep 4,877 Posts Drives: 2016 340i xDrive Join Date: Apr 2008 Location: Calgary iTrader: (0)	Does CA get "winter fuel" like us up north? We experience a substantial mileage loss when the fuel gets swapped over (which would be similar to what you are seeing).
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12-20-2018, 08:04 PM	#10
gizmo32 Private 24 Rep 80 Posts Drives: 19 audi s4 Join Date: Feb 2015 Location: Alberta iTrader: (0)	my mileage in winter goes from 600km plus (summer) to around 480-530 km a tank
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12-20-2018, 08:31 PM	#12
gds52 Colonel 886 Rep 2,720 Posts Drives: BMW Z4M Coupe, BMW 328i E93 Co Join Date: Oct 2011 Location: NJ iTrader: (0)	Where have you been filling up. Not sure if you know Wawa gas stations in East.....worst gas ever. My 3 cars' mileage dropped like crazy....then I searched and people were calling out Wawa gas the worst. Some ppl had their cars' fuel pump replaced. I wrote to Wawa...the said if you have any repair send us the bill...lol. Make sure to get good gas.....look for Top Tier
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12-21-2018, 10:11 AM	#15
agentorange Major 1508 Rep 1,387 Posts Drives: 328d Join Date: Nov 2018 Location: Desert SW iTrader: (0)	IIRC winter gas in CA (if not all gas) has about 10% ethanol. That doesn't do your mileage any favors.
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12-27-2018, 12:06 AM	#17
JimBean2014 Second Lieutenant 44 Rep 275 Posts Drives: 2020 X3 M40I Join Date: Sep 2014 Location: San Diego CA iTrader: (0)	Update: Just got the oil change done with the dealer and they couldn't verify the mpg drop.. however, they mentioned my car has Dinan piggyback.I know my car has MPPSK but didn't know about Dinan. Will someone be able to confirm from the pic? Attached Images
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