Gas Gauge
 

Forgive me if this has been covered in another thread in the past. As a new member, I did a search but found nothing like what I am experiencing.

I purchased a 2013 FR-S a week ago. Yesterday, I had about 3/4 of a tank of gas and I was going to top it off to full. After filling up, I got back in the car and noticed that gas gauge had not moved from the 3/4 mark to full. Has anyone else had this happen or know what might be the cause?

I am going to drive the car for a while longer to see if the gauge drops. If it does, I will then fill it up again and see if the needle points to full or not.

Happened to my 17 86 once. From what I read it is normal as it is a compensation thing so that the fuel gauge stays pretty steady so a small change it won't register. Mine never did it since but I usually always fill it at least below 3/4 tank.

22R

Thanks 22R. Hopefully the gauge will drop as I continue to drive it, and then I will fill up the tank and see where the needle points at that point, being there will be a greater distance to move at that time.

Normal for this car. Just don't fill until below a half tank.

Was the car running while you were filling it or the ignition at the "on" position?

No, the car engine was completely off.

I've noticed this as well on my car, it is a 2013. I've just waited until the gauge drops to 1/2 tank and you won't see the issue. Not sure why this happens on our cars :iono:

Very interesting. At least I'm not alone. I will definitely wait until it drops below 1/2 to fill. Until then, until the tank drops below 3/4, it will look like I'm getting GREAT gas mileage. :D

Because these cars are built for violent lateral maneuvers that slosh the gas around in the tank and would make your fuel gauge bob up and down like a cheerleader's head on prom night if it wasn't designed to dampen out small changes in level.

While on the topic of the gas gauge... How much is typically left in the tank when the gas light comes on?

Loads.
Mine comes on pretty much weekly. Have driven as many as 30 miles after it comes on and have never run out.

I think I've hit around 40-50, I was just curious if anyone had an "exact'er" number as I'm going to be traveling to Canada this weekend and who knows how many miles I'm going to have to drive to get gas when there ;)

The consensus seems to be about 3 gallons remain when the light comes on.


Where are you going in Canada? You realize we have gas stations all over just like you do right?

Haha of course, I was just pulling your leg. I've been numerous times before - just never drove the distance in the FR-S.

Well it is almost September


https://www.patrickmorin.com/DATA/PR...inal/12884.jpg

About 2.5 US gallons. I carried a gallon of gas and drove mine empty once, just to see.


edit: In detail, I filled, drove until light on, refilled and noted quantity, drove empty, added one gallon and took it into account when I filled again.

without exact-er numbers, when the light came on i have once due to necessity, gone about 60 miles without the ac draining power, going about 60 mph drafting big rigs on interstate. i now estimate 50 miles and often stop sooner when light comes on.

I have an old Galaxy Note that I use as an engine monitor running Torque. I have it set up to run a fuel gauge that reads out what the car's computer thinks is left in the tank, displayed in gallons.

The light consistently comes on when the car thinks it has 2.4 gallons of usable fuel left. There is literally zero variation in that number from what I have observed. It's always 2.4 gallons. I'm not sure if that's what's actually in the tank, but that's what the car thinks is there.

Whoever said three gallons isn't wrong either, though. 2.4 usable gallons is about three gallons of actual fuel in the tank, since there's roughly a half gallon of fuel at the bottom of the tank below the pickup that the car can't use. Tcoat can confirm that the unusable fuel at the bottom is to give water and debris a place to collect without being sucked up into the pickup.