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DISCUSSION => General Topics => Topic started by: txleadfoot on April 21, 2009, 10:15:33 AM

Title: Reserve Fuel Light Mileage
Post by: txleadfoot on April 21, 2009, 10:15:33 AM
OK, I did some math trying to figure out an approximate figure for expected miles after the reserve fuel light illuminates.  Most of my driving is commuting to work in the city in light traffic.

The facts:
Mileage at fill-up: 333.3 mi.
Fuel at fill-up:  14.76 gal.
MPG:  22.6
Miles at reserve light:  329.0
Fuel Tank Capacity:  16.4

From my calculations, the reserve fuel light comes on at 1.83 gal. remaining.  In my case, that translates to an additional 41.35 miles after the light illuminates, totaling a possible 370.3 miles to a tank.
Title: Reserve Fuel Light Mileage
Post by: JP 91iS on April 21, 2009, 12:14:29 PM
The E30 M42's have 14 gal tank right? I think for us the light comes on with 2 gallons left, at least that's what someone told me.
Title: Reserve Fuel Light Mileage
Post by: carlos318is on April 21, 2009, 03:22:56 PM
I have done about 45miles:eek: from when the light came on I didnt want to risk running out after that as it was going to be a long walk to the garage:(
Title: Reserve Fuel Light Mileage
Post by: monty23psk on April 21, 2009, 09:54:39 PM
I got 32 miles once, was starting to stall as I pulled into gas station. I guess depends how you drive it the last 2 gallons.
Title: Reserve Fuel Light Mileage
Post by: bmw327 on April 21, 2009, 10:57:46 PM
As I understand it, the 318's have a 14.5 gal (55L) tank  My light typically comes on at ~300 miles and the two times it came on, the car required 12.3 and 12.8 gal, respectively, yielding 23.8 and 24.5 mpg.
Title: Reserve Fuel Light Mileage
Post by: 3seriesNut on April 21, 2009, 11:02:21 PM
my gas light came on tonight when i was leaving the hospital at 290  miles i drove to the station and when i shut it down the trip odo was at 310miles. $11.67 or 4.88gal gave me a cunthair under 1/2 tank.
Title: Ut-oh
Post by: txleadfoot on April 21, 2009, 11:06:33 PM
I just checked the owner's manual and yes, the fuel tank capacity on the 318i is 55 liters or 14.5 gal.  Looks like I need to recalculate!

Quote from: bmw327;70543
As I understand it, the 318's have a 14.5 gal (55L) tank  My light typically comes on at ~300 miles and the two times it came on, the car required 12.3 and 12.8 gal, respectively, yielding 23.8 and 24.5 mpg.
Title: Reserve Fuel Light Mileage
Post by: ///m42 sport on April 21, 2009, 11:26:10 PM
wow, looks like I'm too cautious. The most I've had to fill up was 11 gallons and I thought I was running on empty.  Good info to know.

On a side note, I noticed my fill gauge is sporadic sometimes.  Like it reads 1/4 full for a while, then 1/2 full then 1/3 full.  There's no gradual decrease in fuel consumption.  Does this have anything to do with the distribution of gas in the tank or is it more likely the gauge?
Title: Reserve Fuel Light Mileage
Post by: 1991 E30 M42 on April 22, 2009, 01:44:14 AM
i have run my car completely out of gas as i was pulling into a gas station and it took almost exactly 14 gallons to fill it up
Title: Reserve Fuel Light Mileage
Post by: Meister on April 29, 2009, 01:05:29 AM
Mine comes on at around 290Miles on a full tank.  The longest that I've driven with the light on was about 315Miles.  I filled it up with almost 13 gallons
Title: Reserve Fuel Light Mileage
Post by: parker575 on May 04, 2009, 02:37:16 PM
The most I've put in is about 12.9 gallons, I've never completely emptied the tank.
Title: Reserve Fuel Light Mileage
Post by: gearheadE30 on May 04, 2009, 08:37:41 PM
huh, I thought mine had a 12.7 or something. I put 12.6 in it after it died pulling into the lot....
Title: Reserve Fuel Light Mileage
Post by: sports.racer on May 04, 2009, 10:35:29 PM
I put about 12.6 or so gallons in when the light comes on. Not getting anywhere near 300 miles at that point though. Need to work on that.
Title: Reserve Fuel Light Mileage
Post by: twright on May 05, 2009, 05:53:48 AM
I put a gallon of gas in the trunk, so that I could see how far mine would go after the light came on.  On the highway (at 65 mph) my car went 41 miles until it was empty, after the light turned on.

YMMV.
Title: Reserve Fuel Light Mileage
Post by: Mrod 91 318IS on May 05, 2009, 10:17:33 PM
My light comes on at about 330 miles and when I fill up I usually have to put in about 13 gallons
Title: Reserve Fuel Light Mileage
Post by: roundel318 on May 05, 2009, 10:38:27 PM
I pull 335 miles when the light comes on, then have seen up to 37 miles after that before filling up.