Fuel Capacity

How Much Usable Fuel Does the NSX Hold?

[A/H] Several weeks ago one of the members of this list asked about the low fuel light. I responded to him that the light will not come on until the needle is on the empty line. The specifications state that the tank will have 2 liters of fuel when the engine quits, and that the usable fuel is 70 liters. I then conducted a test by running a car out of fuel and then measuring fuel as it went in:

  • 2.7 gallons (10.25 liters) - The low fuel light went off
  • 18.6 gallons (70.43 liters) - Full (first click off)
  • 15.9 gallons (60.18 liters) - Usable fuel in the tank before the low fuel light activates.

This test was done on my 1991 5-speed. I have no information that the fuel system was changed through the 1996 model year but every car may vary a little bit from these numbers.

[LE] The other day my fuel light lit up just as I was pulling into the gas station. My ’91 took 15.17 gallons from the low fuel light first coming on to first click-off at the fuel pump, which is almost a gallon less than above.

[FG – 99/6/10] When the gas light on the NSX is on CONSISTENTLY, you have about 2.5 US gallons left. I’ve used this as a GUIDELINE for my cars on the street and it has always worked. I’ve been able to predict how much gas I’m going to need within about 1/10 gallon.

[A/H – 2000/7/24] With a 1999 model year NSX  I watched it go to about the middle of the Red empty mark and stay there for about 30 miles. Then the Low Fuel Light came on and I continued to drive for 32 more miles. I filled up and put in 16.2 after two clicks. The Owners manual states 18.5 gallons. I figured less than 1 gallon not usable in the tank should have given me another 25 to 30 miles before the engine quit.

"Topping Off" The Tank

[GM] I’ve seen the signs at gas stations asking people to refrain from topping off the gas tank when refueling. I’ve always thought this procedure referred to avoiding spilling any gas on the pavement, and therefore not releasing any gas vapors to the atmosphere and compounding air pollution problems.

The actual reason is different. All modern cars including the NSX have vapor recovery systems for the fuel system. If the gasoline in the tank later expands due to temperature, excess gasoline may be forced into the charcoal canister. If this happens often or even one significant time it can ruin the canister.

So … don’t top off when refueling because it can damage your NSX!

How Does Fuel Affect Weight Distribution?

Another interesting item along this line would be where the fuel tank is placed. In 1991 competitive info states that the NSX with a full tank had weight distribution of 42% front, 58% rear, this number will change by .5% when the fuel tank is empty. The Porsche 911 will change by 2.25%.

Technical Information