I have Googled, read the owner’s manual, and even spoken with my local mechanic, and I have yet to find an answer to this question…
I own a 1993 Buick Regal Custom, 3.8L V6. When I am running low on gas, the low fuel light turns on. I would like to know how much fuel is left in my gas tank when the light turns on. I would imagine somewhere between 1/2 gallon - 1 gallon. As it is now, I try to put gas in the tank within 10 miles of the light turning on. Do I have more miles to spare, or is this about right?
I think Buick sets it right around a 1/16 of a tank, as per the readout.
That’s about 1.5 gallons on display, plus about 1-2 they leave as room for error in setting the gauge.
You’ll be pressed to get an exact answer, but you have about 1.5-3.5 gallons.
I have a '95 same engine, good engine! My low fuel light turns on with about 40 miles left to travel, which is about 2 gallons. Every car will be a little different on this, and your car will vary from fillup to fillup, not much, but 1/4 gallon or so.
I believe the fuel tank holds 16 gallons, you can figure it from there. ( If you have an Owners manual, it will say how big the tank is) Just FYI, my Wife’s older Buick ran out of fuel with 3 gallons displayed on the digital display. (She was not happy)
1-Fill up to automatic shutoff at pump.
2-After your 300 mi.or so drive makes light go on,pull into gas station (1 or 2 miles further won’t make that much of a difference capacitywise to your tankfull.)
3-Fill up gas tank to automatic shutoff.
4-look at gallons dispensed-subtract from gas tank capacity=amount left when low fuel warning appears.
Mine is abt.1.6 on a 16 gal.tank (not Buick),which equals abt. 40 miles left by virtue of a 23 mpg avg.YMMV
Unless you need this answer for a report or something this will get you within 1/10 of a gallon or so.