Very slightly low temps, this affect mileage?

BimmerToolRental · 06-20-2015, 07:06 PM

Been tracking down sub normal mileage.

Averaging 27 with 60-70% highway. CBU just completed at BMW with same results. I noticed this morning that my temps were 185f while driving, 186.6 at idle. This evening the temps outside are mid 90's and the car was at 188f driving. Is this enough to make a difference as its pretty close to the 190f the t-stat calls for.

Also just completed this week as part of normal maintenance and tracking down mileage issue. Car has 54.5k on it :

- Trans fluid, pan, sleeve
- Fuel Filter
- Oil Change

dixy2k · 06-20-2015, 09:26 PM

I call that normal operating range. I don't like it when mine gets up to 195F.

Hoooper · 06-21-2015, 09:57 AM

188.6F is 87C. My understanding is that is normal operating temp

grant123 · 06-22-2015, 09:53 AM

at 70mph mines usually at 89-91 degrees c, yours looks quite low

mefferso · 06-24-2015, 11:32 AM

Well crap. After reading this thread i thought I should check mine with torque. Looks like im running at ~80C or 180F under peak normal operating conditions. Haven't checked how high it gets when doing a regen.

Worth changing my thermostat at this temp?

TDIwyse · 06-24-2015, 12:37 PM

Quote:

Originally Posted by mefferso

...Looks like im running at ~80C or 180F under peak normal operating conditions...

That's what mine normally runs at after doing all the deletes. It'll creep up to 185 on extremely hot days if using the AC and in stop-n-go traffic. Has been that way for a long, long time now. Haven't had any issues with fuel efficiency or power output with ~180F coolant temps.

mefferso · 06-25-2015, 12:19 PM

Quote:

Originally Posted by TDIwyse

That's what mine normally runs at after doing all the deletes. It'll creep up to 185 on extremely hot days if using the AC and in stop-n-go traffic. Has been that way for a long, long time now. Haven't had any issues with fuel efficiency or power output with ~180F coolant temps.

Thanks for the feedback. Just caught the end of a regen this morning and it looked to be in the mid 190sF

Hoooper · 06-25-2015, 03:44 PM

Mine tops out about 170F. I sure hope it is damaging to mileage so that after I fix it I get a bump up from the 32-35 I get now

dixy2k · 06-25-2015, 09:37 PM

170? wow. how do you get that low temp?
my oscillates between 185-195 on the freeway and 195-206 on the streets.

Hoooper · 06-26-2015, 02:32 AM

Haha I don't do it on purpose. It starts out at 60 or so and just doesn't get above that at normal driving. In the morning it's even cooler.

BimmerToolRental · 06-28-2015, 08:33 PM

Just an FYI, i was wrong. I didn't let the car warm up long enough. The temps are correct @190.

06-20-2015, 07:06 PM	#1
BimmerToolRental Wannabe Mechanic 8 Rep 54 Posts Drives: 2011 E90 335D Join Date: Apr 2015 Location: Raleigh, NC iTrader: (0)	Very slightly low temps, this affect mileage? Been tracking down sub normal mileage. Averaging 27 with 60-70% highway. CBU just completed at BMW with same results. I noticed this morning that my temps were 185f while driving, 186.6 at idle. This evening the temps outside are mid 90's and the car was at 188f driving. Is this enough to make a difference as its pretty close to the 190f the t-stat calls for. Also just completed this week as part of normal maintenance and tracking down mileage issue. Car has 54.5k on it : - Trans fluid, pan, sleeve - Fuel Filter - Oil Change
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06-20-2015, 09:26 PM	#2
dixy2k Major 88 Rep 1,151 Posts Drives: 335d Join Date: Nov 2009 Location: CA iTrader: (0)	I call that normal operating range. I don't like it when mine gets up to 195F.
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06-21-2015, 09:57 AM	#3
Hoooper Colonel 213 Rep 2,210 Posts Drives: 335D Join Date: Jun 2013 Location: Petaluma, CA iTrader: (0)	188.6F is 87C. My understanding is that is normal operating temp
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06-22-2015, 09:53 AM	#4
grant123 New Member 0 Rep 7 Posts Drives: 330D Join Date: Jun 2015 Location: leeds, uk iTrader: (0)	at 70mph mines usually at 89-91 degrees c, yours looks quite low
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06-24-2015, 11:32 AM	#5
mefferso Second Lieutenant 44 Rep 239 Posts Drives: 2010 335d Join Date: Feb 2014 Location: Covington, Louisiana iTrader: (0)	Well crap. After reading this thread i thought I should check mine with torque. Looks like im running at ~80C or 180F under peak normal operating conditions. Haven't checked how high it gets when doing a regen. Worth changing my thermostat at this temp? __________________ Last edited by mefferso; 06-24-2015 at 12:30 PM..
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06-25-2015, 03:44 PM	#8
Hoooper Colonel 213 Rep 2,210 Posts Drives: 335D Join Date: Jun 2013 Location: Petaluma, CA iTrader: (0)	Mine tops out about 170F. I sure hope it is damaging to mileage so that after I fix it I get a bump up from the 32-35 I get now
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06-25-2015, 09:37 PM	#9
dixy2k Major 88 Rep 1,151 Posts Drives: 335d Join Date: Nov 2009 Location: CA iTrader: (0)	170? wow. how do you get that low temp? my oscillates between 185-195 on the freeway and 195-206 on the streets.
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06-26-2015, 02:32 AM	#10
Hoooper Colonel 213 Rep 2,210 Posts Drives: 335D Join Date: Jun 2013 Location: Petaluma, CA iTrader: (0)	Haha I don't do it on purpose. It starts out at 60 or so and just doesn't get above that at normal driving. In the morning it's even cooler.
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06-28-2015, 08:33 PM	#11
BimmerToolRental Wannabe Mechanic 8 Rep 54 Posts Drives: 2011 E90 335D Join Date: Apr 2015 Location: Raleigh, NC iTrader: (0)	Just an FYI, i was wrong. I didn't let the car warm up long enough. The temps are correct @190.
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