Isuzu Ascender Gas Tank Size (2003 - 2008): Fuel Tank Capacity Data

Researched By The AutoPadre Research Team

Last Updated 2023-04-01

The Isuzu Ascender gas tank sizes range from 21.7 gallons to 25.0 gallons as specified in our data below, organized by trim, option package, and model year.

The gas tank size of the Isuzu Ascender, when combined with its fuel mileage, gives the Ascender the following ranges depending on the model year and options:

City range from 303 miles to 400 miles
Highway range from 434 miles to 550 miles

Check out the Gas Tank Size specifications for other makes and models.

2008 Isuzu Ascender Gas Tank Size

The 2008 Isuzu Ascender gas tank size is 21.7 gallons.

On a full tank of fuel, the 2008 Isuzu Ascender has the following ranges:

City range of 303 miles
Highway range of 434 miles

2008 Isuzu Ascender Gas Tank Size (Imp.)
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (miles)
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	21.7 gal.	303 city \| 434 hwy \| 368 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	21.7 gal.	303 city \| 434 hwy \| 368 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	21.7 gal.	303 city \| 434 hwy \| 368 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	21.7 gal.	303 city \| 434 hwy \| 368 combined
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	21.7 gal.	303 city \| 434 hwy \| 368 combined
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	21.7 gal.	303 city \| 434 hwy \| 368 combined

2008 Isuzu Ascender Gas Tank Size (Metric)
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (km)
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	82.1 liters	488 city \| 698 hwy \| 592 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	82.1 liters	488 city \| 698 hwy \| 592 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	82.1 liters	488 city \| 698 hwy \| 592 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	82.1 liters	488 city \| 698 hwy \| 592 combined
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	82.1 liters	488 city \| 698 hwy \| 592 combined
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	82.1 liters	488 city \| 698 hwy \| 592 combined

2007 Isuzu Ascender Gas Tank Size

The 2007 Isuzu Ascender gas tank size is 21.7 gallons.

On a full tank of fuel, the 2007 Isuzu Ascender has the following ranges depending on the trim level:

City range from 325 miles to 347 miles
Highway range from 455 miles to 477 miles

2007 Isuzu Ascender Gas Tank Size (Imp.)
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (miles)
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	21.7 gal.	325 city \| 455 hwy \| 390 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	21.7 gal.	347 city \| 477 hwy \| 412 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	21.7 gal.	325 city \| 455 hwy \| 390 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	21.7 gal.	347 city \| 477 hwy \| 412 combined
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	21.7 gal.	325 city \| 455 hwy \| 390 combined
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	21.7 gal.	347 city \| 477 hwy \| 412 combined

2007 Isuzu Ascender Gas Tank Size (Metric)
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (km)
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	82.1 liters	523 city \| 732 hwy \| 628 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	82.1 liters	558 city \| 768 hwy \| 663 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	82.1 liters	523 city \| 732 hwy \| 628 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	82.1 liters	558 city \| 768 hwy \| 663 combined
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	82.1 liters	523 city \| 732 hwy \| 628 combined
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	82.1 liters	558 city \| 768 hwy \| 663 combined

2006 Isuzu Ascender Gas Tank Size

The 2006 Isuzu Ascender gas tank sizes range between 21.7 and 25.0 gallons depending on the trim level and model options.

On a full tank of fuel, the 2006 Isuzu Ascender has the following ranges depending on the trim level:

City range from 325 miles to 400 miles
Highway range from 455 miles to 550 miles

2006 Isuzu Ascender Gas Tank Size (Imp.)
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (miles)
LS SUV	5.3L \| V8 \| OHV MPFI \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	25.0 gal.	375 city \| 500 hwy \| 437 combined
LS SUV	5.3L \| V8 \| OHV MPFI \| 4 Spd Hydra-Matic Auto w/OD \| RWD	25.0 gal.	400 city \| 550 hwy \| 475 combined
Limited SUV	5.3L \| V8 \| OHV MPFI \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	25.0 gal.	375 city \| 500 hwy \| 437 combined
Limited SUV	5.3L \| V8 \| OHV MPFI \| 4 Spd Hydra-Matic Auto w/OD \| RWD	25.0 gal.	400 city \| 550 hwy \| 475 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	25.0 gal.	375 city \| 500 hwy \| 437 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	25.0 gal.	375 city \| 500 hwy \| 437 combined

2006 Isuzu Ascender Gas Tank Size (Imp.) Continued
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (miles)
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	25.0 gal.	375 city \| 500 hwy \| 437 combined
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	25.0 gal.	375 city \| 500 hwy \| 437 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	21.7 gal.	325 city \| 455 hwy \| 390 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	21.7 gal.	347 city \| 477 hwy \| 412 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	21.7 gal.	325 city \| 455 hwy \| 390 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	21.7 gal.	347 city \| 477 hwy \| 412 combined

2006 Isuzu Ascender Gas Tank Size (Imp.) Continued
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (miles)
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	21.7 gal.	325 city \| 455 hwy \| 390 combined
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	21.7 gal.	347 city \| 477 hwy \| 412 combined

2006 Isuzu Ascender Gas Tank Size (Metric)
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (km)
LS SUV	5.3L \| V8 \| OHV MPFI \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	94.6 liters	604 city \| 805 hwy \| 703 combined
LS SUV	5.3L \| V8 \| OHV MPFI \| 4 Spd Hydra-Matic Auto w/OD \| RWD	94.6 liters	644 city \| 885 hwy \| 764 combined
Limited SUV	5.3L \| V8 \| OHV MPFI \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	94.6 liters	604 city \| 805 hwy \| 703 combined
Limited SUV	5.3L \| V8 \| OHV MPFI \| 4 Spd Hydra-Matic Auto w/OD \| RWD	94.6 liters	644 city \| 885 hwy \| 764 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	94.6 liters	604 city \| 805 hwy \| 703 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	94.6 liters	604 city \| 805 hwy \| 703 combined

2006 Isuzu Ascender Gas Tank Size (Metric) Continued
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (km)
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	94.6 liters	604 city \| 805 hwy \| 703 combined
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	94.6 liters	604 city \| 805 hwy \| 703 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	82.1 liters	523 city \| 732 hwy \| 628 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	82.1 liters	558 city \| 768 hwy \| 663 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	82.1 liters	523 city \| 732 hwy \| 628 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	82.1 liters	558 city \| 768 hwy \| 663 combined

2006 Isuzu Ascender Gas Tank Size (Metric) Continued
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (km)
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	82.1 liters	523 city \| 732 hwy \| 628 combined
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	82.1 liters	558 city \| 768 hwy \| 663 combined

2005 Isuzu Ascender Gas Tank Size

The 2005 Isuzu Ascender gas tank sizes range between 21.7 and 25.0 gallons depending on the trim level and model options.

On a full tank of fuel, the 2005 Isuzu Ascender has the following ranges depending on the trim level:

City range from 325 miles to 375 miles
Highway range from 434 miles to 500 miles

2005 Isuzu Ascender Gas Tank Size (Imp.)
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (miles)
LS SUV	5.3L \| V8 \| OHV MPFI \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	25.0 gal.	350 city \| 475 hwy \| 412 combined
LS SUV	5.3L \| V8 \| OHV MPFI \| 4 Spd Hydra-Matic Auto w/OD \| RWD	25.0 gal.	375 city \| 500 hwy \| 437 combined
Limited SUV	5.3L \| V8 \| OHV MPFI \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	25.0 gal.	350 city \| 475 hwy \| 412 combined
Limited SUV	5.3L \| V8 \| OHV MPFI \| 4 Spd Hydra-Matic Auto w/OD \| RWD	25.0 gal.	375 city \| 500 hwy \| 437 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	25.0 gal.	375 city \| 500 hwy \| 437 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	25.0 gal.	375 city \| 475 hwy \| 425 combined

2005 Isuzu Ascender Gas Tank Size (Imp.) Continued
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (miles)
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	25.0 gal.	375 city \| 500 hwy \| 437 combined
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	25.0 gal.	375 city \| 475 hwy \| 425 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	21.7 gal.	325 city \| 434 hwy \| 379 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	21.7 gal.	347 city \| 455 hwy \| 401 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	21.7 gal.	325 city \| 434 hwy \| 379 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	21.7 gal.	347 city \| 455 hwy \| 401 combined

2005 Isuzu Ascender Gas Tank Size (Imp.) Continued
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (miles)
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	21.7 gal.	325 city \| 434 hwy \| 379 combined
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	21.7 gal.	347 city \| 455 hwy \| 401 combined

2005 Isuzu Ascender Gas Tank Size (Metric)
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (km)
LS SUV	5.3L \| V8 \| OHV MPFI \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	94.6 liters	563 city \| 764 hwy \| 663 combined
LS SUV	5.3L \| V8 \| OHV MPFI \| 4 Spd Hydra-Matic Auto w/OD \| RWD	94.6 liters	604 city \| 805 hwy \| 703 combined
Limited SUV	5.3L \| V8 \| OHV MPFI \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	94.6 liters	563 city \| 764 hwy \| 663 combined
Limited SUV	5.3L \| V8 \| OHV MPFI \| 4 Spd Hydra-Matic Auto w/OD \| RWD	94.6 liters	604 city \| 805 hwy \| 703 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	94.6 liters	604 city \| 805 hwy \| 703 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	94.6 liters	604 city \| 764 hwy \| 684 combined

2005 Isuzu Ascender Gas Tank Size (Metric) Continued
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (km)
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	94.6 liters	604 city \| 805 hwy \| 703 combined
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	94.6 liters	604 city \| 764 hwy \| 684 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	82.1 liters	523 city \| 698 hwy \| 610 combined
S SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	82.1 liters	558 city \| 732 hwy \| 645 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	82.1 liters	523 city \| 698 hwy \| 610 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	82.1 liters	558 city \| 732 hwy \| 645 combined

2005 Isuzu Ascender Gas Tank Size (Metric) Continued
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (km)
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| 4WD	82.1 liters	523 city \| 698 hwy \| 610 combined
LS SUV	4.2L \| I6 \| 4 Spd Hydra-Matic Auto w/OD \| RWD	82.1 liters	558 city \| 732 hwy \| 645 combined

2004 Isuzu Ascender Gas Tank Size

The 2004 Isuzu Ascender gas tank sizes range between 22.0 and 25.0 gallons depending on the trim level and model options.

On a full tank of fuel, the 2004 Isuzu Ascender has the following ranges depending on the trim level:

City range from 330 miles to 400 miles
Highway range from 450 miles to 500 miles

2004 Isuzu Ascender Gas Tank Size (Imp.)
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (miles)
LS SUV	5.3L \| V8 \| OHV \| 4 Spd Auto w/OD Hydra-Matic \| 4WD	25.0 gal.	350 city \| 450 hwy \| 400 combined
LS SUV	5.3L \| V8 \| OHV \| 4 Spd Auto w/OD Hydra-Matic \| RWD	25.0 gal.	400 city \| 475 hwy \| 437 combined
Limited SUV	5.3L \| V8 \| OHV \| 4 Spd Auto w/OD Hydra-Matic \| 4WD	25.0 gal.	350 city \| 450 hwy \| 400 combined
Limited SUV	5.3L \| V8 \| OHV \| 4 Spd Auto w/OD Hydra-Matic \| RWD	25.0 gal.	400 city \| 475 hwy \| 437 combined
S SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| 4WD	25.0 gal.	375 city \| 500 hwy \| 437 combined
S SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| RWD	25.0 gal.	375 city \| 475 hwy \| 425 combined

2004 Isuzu Ascender Gas Tank Size (Imp.) Continued
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (miles)
LS SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| 4WD	25.0 gal.	375 city \| 500 hwy \| 437 combined
LS SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| RWD	25.0 gal.	375 city \| 475 hwy \| 425 combined
S SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| 4WD	22.0 gal.	330 city \| 462 hwy \| 396 combined
S SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| RWD	22.0 gal.	352 city \| 462 hwy \| 407 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| 4WD	22.0 gal.	330 city \| 462 hwy \| 396 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| RWD	22.0 gal.	352 city \| 462 hwy \| 407 combined

2004 Isuzu Ascender Gas Tank Size (Imp.) Continued
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (miles)
LS SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| 4WD	22.0 gal.	330 city \| 462 hwy \| 396 combined
LS SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| RWD	22.0 gal.	352 city \| 462 hwy \| 407 combined

2004 Isuzu Ascender Gas Tank Size (Metric)
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (km)
LS SUV	5.3L \| V8 \| OHV \| 4 Spd Auto w/OD Hydra-Matic \| 4WD	94.6 liters	563 city \| 724 hwy \| 644 combined
LS SUV	5.3L \| V8 \| OHV \| 4 Spd Auto w/OD Hydra-Matic \| RWD	94.6 liters	644 city \| 764 hwy \| 703 combined
Limited SUV	5.3L \| V8 \| OHV \| 4 Spd Auto w/OD Hydra-Matic \| 4WD	94.6 liters	563 city \| 724 hwy \| 644 combined
Limited SUV	5.3L \| V8 \| OHV \| 4 Spd Auto w/OD Hydra-Matic \| RWD	94.6 liters	644 city \| 764 hwy \| 703 combined
S SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| 4WD	94.6 liters	604 city \| 805 hwy \| 703 combined
S SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| RWD	94.6 liters	604 city \| 764 hwy \| 684 combined

2004 Isuzu Ascender Gas Tank Size (Metric) Continued
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (km)
LS SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| 4WD	94.6 liters	604 city \| 805 hwy \| 703 combined
LS SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| RWD	94.6 liters	604 city \| 764 hwy \| 684 combined
S SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| 4WD	83.3 liters	531 city \| 744 hwy \| 637 combined
S SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| RWD	83.3 liters	566 city \| 744 hwy \| 655 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| 4WD	83.3 liters	531 city \| 744 hwy \| 637 combined
Luxury SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| RWD	83.3 liters	566 city \| 744 hwy \| 655 combined

2004 Isuzu Ascender Gas Tank Size (Metric) Continued
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (km)
LS SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| 4WD	83.3 liters	531 city \| 744 hwy \| 637 combined
LS SUV	4.2L \| I6 \| 4 Spd Auto w/OD Hydra-Matic \| RWD	83.3 liters	566 city \| 744 hwy \| 655 combined

2003 Isuzu Ascender Gas Tank Size

The 2003 Isuzu Ascender gas tank size is 25.0 gallons.

On a full tank of fuel, the 2003 Isuzu Ascender has the following ranges depending on the trim level:

City range from 350 miles to 375 miles
Highway range from 450 miles to 475 miles

2003 Isuzu Ascender Gas Tank Size (Imp.)
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (miles)
LS SUV	4.2L \| I6 \| DOHC 24-VALVE \| 4 Spd Auto w/OD Hyrda-Matic \| 4WD	25.0 gal.	350 city \| 450 hwy \| 400 combined
LS SUV	4.2L \| I6 \| DOHC 24-VALVE \| 4 Spd Auto w/OD Hyrda-Matic \| RWD	25.0 gal.	375 city \| 475 hwy \| 425 combined
Limited SUV	4.2L \| I6 \| DOHC 24-VALVE \| 4 Spd Auto w/OD Hyrda-Matic \| 4WD	25.0 gal.	350 city \| 450 hwy \| 400 combined
Limited SUV	4.2L \| I6 \| DOHC 24-VALVE \| 4 Spd Auto w/OD Hyrda-Matic \| RWD	25.0 gal.	375 city \| 475 hwy \| 425 combined
S SUV	4.2L \| I6 \| DOHC 24-VALVE \| 4 Spd Auto w/OD Hyrda-Matic \| 4WD	25.0 gal.	350 city \| 450 hwy \| 400 combined
S SUV	4.2L \| I6 \| DOHC 24-VALVE \| 4 Spd Auto w/OD Hyrda-Matic \| RWD	25.0 gal.	375 city \| 475 hwy \| 425 combined

2003 Isuzu Ascender Gas Tank Size (Imp.) Continued
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (miles)
LS SUV	4.2L \| I6 \| DOHC 24-VALVE \| 4 Spd Auto w/OD Hyrda-Matic \| 4WD	25.0 gal.	350 city \| 450 hwy \| 400 combined
LS SUV	4.2L \| I6 \| DOHC 24-VALVE \| 4 Spd Auto w/OD Hyrda-Matic \| RWD	25.0 gal.	375 city \| 475 hwy \| 425 combined

2003 Isuzu Ascender Gas Tank Size (Metric)
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (km)
LS SUV	4.2L \| I6 \| DOHC 24-VALVE \| 4 Spd Auto w/OD Hyrda-Matic \| 4WD	94.6 liters	563 city \| 724 hwy \| 644 combined
LS SUV	4.2L \| I6 \| DOHC 24-VALVE \| 4 Spd Auto w/OD Hyrda-Matic \| RWD	94.6 liters	604 city \| 764 hwy \| 684 combined
Limited SUV	4.2L \| I6 \| DOHC 24-VALVE \| 4 Spd Auto w/OD Hyrda-Matic \| 4WD	94.6 liters	563 city \| 724 hwy \| 644 combined
Limited SUV	4.2L \| I6 \| DOHC 24-VALVE \| 4 Spd Auto w/OD Hyrda-Matic \| RWD	94.6 liters	604 city \| 764 hwy \| 684 combined
S SUV	4.2L \| I6 \| DOHC 24-VALVE \| 4 Spd Auto w/OD Hyrda-Matic \| 4WD	94.6 liters	563 city \| 724 hwy \| 644 combined
S SUV	4.2L \| I6 \| DOHC 24-VALVE \| 4 Spd Auto w/OD Hyrda-Matic \| RWD	94.6 liters	604 city \| 764 hwy \| 684 combined

2003 Isuzu Ascender Gas Tank Size (Metric) Continued
Trim	Engine \| Transmission \| Drivetrain	Gas Tank Size	Range (km)
LS SUV	4.2L \| I6 \| DOHC 24-VALVE \| 4 Spd Auto w/OD Hyrda-Matic \| 4WD	94.6 liters	563 city \| 724 hwy \| 644 combined
LS SUV	4.2L \| I6 \| DOHC 24-VALVE \| 4 Spd Auto w/OD Hyrda-Matic \| RWD	94.6 liters	604 city \| 764 hwy \| 684 combined