Just wondering!

I have a Chevy Captiva Sport, 2014. I thought my fuel tank capacity was 17 gallons. I recently let the fuel light go off but drove right to the service station to fill up. The tank took 17.1 gallons. Does anyone know just how big the fuel tank is on this car?

When you say that you “let the fuel light go off”, do you actually mean that the fuel light lit up?
(I am always confused by people saying that something “went off”, when it actually went…on.)

In any event, the possibilities as I see them (in no particular order) are:

The fuel level sensor is not accurate, and it turns the low fuel warning light on later than it should.
The capacity, as stated in the Owner’s Manual, is not accurate.
The gas pump at that station is not accurate.
You overfilled the tank by not stopping when the gas pump clicked “off” for the first time.

For your sake, I hope that the last possibility is not the case, as repeatedly doing that will contaminate the carbon canister that is the heart of the evaporative emissions system. In a case like that, you may wind up having to replace the canister to the tune of…maybe $300+

Hmmm. The idea of a low fuel light is to never find out the true capacity of the tank. I usually never go below one half tank.

That’s my SOP also, Bing, but some people like to gamble, I guess.

I presume that the .1 gallon was in the fillerneck, and you should never fill it that full.

I’ve known people that have let the tank run dry just to find out how far they could go in case the fuel light went on, but this is not a very logical thing to do.
I watch my fuel gauge and rarely fall below the 1/4 tank mark.

The fuel pump is cooled by the gas that surrounds it, and letting the tank get below the point where the light comes on regularly can overheat the pump and a replacement pump will be necessary much earlier.

As @VDCdriver said you can cause expensive damage doing this.
Continuing to pump after the pump has clicked off is a harmful practice. It is one thing to get to the next nickle, but trying to get that next 32 cents to get to an even dollar can fill the evap system with raw fuel.

Pick your poison; new Evap canister and diagnosis $300…or, a new fuel pump $500 if you are lucky.


“I recently let the fuel light go off but drove right to the service station to fill up.”

My wife works at a car sales lot and drives different cars home all the time. She never knows what she’ll be driving next and most of the vehicles are kept low on gas. It’s not a good investment to put more than a couple bucks worth of gas in a car you will possibly never drive again.

It’s SOP to have the gas pump symbol lit up on the cars she drives. It makes me very nervous riding with her (we live 20 miles from town in a rural area), but she is quite good at using that light as her “gas gauge.” :wink:

We have filled different cars that have the symbol illuminated, in preparation for a road trip and it does not surprise me that that the “advertised” tank capacity doesn’t exactly match with the fill-up amount.


A gas station near me (on Rt 1) is attendant only, and he insisted on going past the cutoff despite me standing there telling him not to. I complained to the manager, but when that happened a second time, I put that place on my “emergencies only” list.

PS. I don’t agree with the “fill it when it’s half empty” philosophy. You waste energy in two ways, first, because you are always carrying around, on average, 3/4 a tank of gas, which could be 90 pounds. Second, the energy to drive to the gas station, plus the wear on the engine due to stoping and starting.

Fill it when it’s less than 1/4 full…


Fuel capacity is never an absolute. In addition…some gas pumps are not that accurate. I found that out last summer when getting gas for my riding mower.

@BillRussell-- My gas-fill routine is coordinated with my visits to Costco.
Since I go there once a week for my low-cost lettuce, cherry tomatoes, sliced turkey, pomegranate juice, etc, it is just much more convenient to get my gas there at the same time.

Costco’s gas is Top Tier, and they charge anywhere from 10 to 30 cents per gallon less than any other station in the area, so that is my go-to gas station. Also, they give me no problem about doing the fueling myself, despite NJ’s supposed ban on self-service.

Now that I am retired, I use only about 1/2 tank of gas most weeks. If I waited until my tank was down to 1/4, I would probably wind up buying gas from stations that are much more expensive than Costco. Hence my practice of filling-up at the 1/2 way point on the gauge.

However, if I am on a highway trip, it is very likely that I will wait until the gauge reads 1/4.

VDCdriver gave a good list above. I’ll add one more item, which is that different pumps probably shut off at different points. The capacity is an approximation for all of these reasons.

I strongly recommend never letting the fuel level get so low that you can’t drive to the nearest hospital in an emergency without stopping for gas.

17.1 gallons.
Next question.

Fuel capacity is never an absolute. In addition....some gas pumps are not that accurate. I found that out last summer when getting gas for my riding mower

They should be. Most states I’ve been in…it’s regulated. They have testers that go out and certify each pump in each station every few years. And if you think a pump is inaccurate you can call the state and file a complaint. There were at least 2 stations in NH that were shut down because of inaccurate pumps. They can be severely fined for this.

The pumps are certified.
The gas cans aren’t.
If the two vary, my money is on the accuracy of the pump.

“I thought my fuel tank capacity was 17 gallons.”

Have you looked in the Owner’s Manual? (It might be 17.9)
Sorry if this has already been asked.

A fuel tank’s listed capacity always allows for some air space and is never calculated to the tippy top of the neck.
Years ago there were some Escort fuel pumps listing two ‘‘capcities’’ …yet the part number of the tank was the same for each.
The capacity was restricted by the vent tube for some odd reason. So, you could get more in if you waited for it to even out above the tip of the vent tube by the added weight of the fuel in the neck.

You probably have a gallon left after the light goes on. The lawyers don’t want to give people a reason for suing after running out of gas.

The fuel does more than just explode in the engine, it also cools the fuel pump. And running out of fuel on a modern engine can trip a bunch of fault codes. Designers provide enough of a “buffer” so that you have sufficient fuel to perform that function and to find a gas pump and fill the tank after the warning light illuminates.

And, yet, people still run out of gas. Repeatedly. And they continue to support the fuel pump manufacturers industry with donations from their prematurely failing fuel pumps. Fortunately, you were smart enough to head straight for a gas station when the light came on.

However, I recommend filling up when the gage reads half full rather than when the light comes on. That way you’ll never run out, never have insufficient fuel pump cooling, and it won’t cost you one penny more.

I also recommend that you never fill the tank beyond where the nozzle shuts itself off. Doing that can cause expensive EVAP system problems.

My 2012 Camry has a stated capacity of 17 gallons. If i fill it when the light comes on I can only get 12. something gallons in. Drives me nuts on long trips because I know I could go 600 miles but usually fill up at just over 500 because the light has been on awhile.

On my '15 Forester if you have less than 2.6 gallons (out of a 15.9gal tank) the low fuel light comes on,I usually fill up when the gauge reads 2-3bars meaning a 1/4tank or less.

Bill Russell is technically correct in his posting. But, no thanks. I try to keep my tank closer to full. I have never run out of gas, and especially here in Mexico, it would be a very unpleasant and dangerous thing.

I am reminded of a fellow worker, Steve, who would not put freon in his car a/c and believed he was personally saving the planet. While his family suffered with 100 degree 100 percent humidity. I suspect the difference in gas mileage between 1/4 and 3/4 tank of gas would not be measurable by a driver without special equipment.

I certainly do not mean to criticize Bill. Though it is political and we are not supposed to do much of that. IMO liberty means being able to do things your own way (ala Frank Sinatra) without being crucified by others, as long as you harm no one in the process.