2009 BMW M3: Just How Big IS This Fuel Tank?
May 15, 2009
Here's something you don't see every day: Red hot headers! I couldn't help posting this photo of BMW's S65B40 V8 on some sort of testing jig even though it has only a little to do with this entry.
When I fired the car up this morning at 4:45 a.m., it told me the fuel range was 27 miles. Okay, but the office is 41 miles away. Hmm. Knowing what an alarmist the fuel warning light is (it chimes and displays a gas pump when the fuel gauge shows a quarter tank for goodness sake), and that the car was computing my range from previous data (collected on my bummer-to-bummer drive home yesterday), I accepted the challenge.
By the time I had reached the freeway from my house, the fuel range display had already gone up to 31 miles. Now, if I could just get it into 6th gear as soon as possible, avoid unnecessary slowing, and keep my speed as consistent as possible, I thought I'd be fine.
Well the display stayed at 31 miles for several miles, briefly went up to 36 miles, but then started plummeting: 27 21 16 18 11 9 5 and finally 1 when I was still 7.5 miles away from the Shell on Clovefrield. Then the display read, "---- mls" from then on.
When I wheeled into the gas station, I felt equally triumphant and relieved. I pumped 17.006 gallons of 91 octane into the tank. When I got to the office, I looked up the official fuel capacity of the M3 Sedan's tank and found it to be 16.6 gallons. Whaaaa?
Consulting the owner's manual, I found that to be a little misleading. It turns out in addition to the 65-liter (16.6 gal) capacity, there are an additional 12.5 liters (3.3 gal) in reserve, or truly 19.94 gallons. Sheesh, I could've driven at least another 40 miles!
Chris Walton, Chief Road Test Editor @ 2,602 miles