2003 Honda Civic Gas Tank Size

The standard 2003 Honda Civic gas tank size holds 13.2 gallons, but the rare GX features an 8-gallon CNG tank.
Written by Maxine Boyko
Reviewed by Jessica Barrett
Updated on Nov 03, 2022
The gas tank in your 2003 Honda Civic strictly holds 13.2 gallons—unless you’re one of the few owners with a GX model, which takes only eight gallons, due to having a standard CNG fuel tank. 
Not knowing the fuel tank capacity on your vehicle may not seem like all that big of a deal—until it comes time to fill up your tank, do your own maintenance or repairs, or your trivia team is counting on you for the right answer. 
No matter your situation,
is here to ensure you don’t come up short—the licensed
car insurance
broker and the
#1-rated insurance app
in the app store has put together a road map to the 2003 Honda Civic gas tank size. 

How big is the gas tank on a 2003 Honda Civic?

The gas tank on a 2003 Honda Civic is the same across all its models—except the GX, a CNG (compressed natural gas) vehicle produced from 1998 through 2015.
While it’s much more likely you own a regular gasoline-powered Civic, we will still go over all the possible tank sizes so no one feels left out. 
Here are the possible configurations, trims, and respective engine types for a 2003 Honda Civic:
Coupe, sedan
1.7-liter 4-cylinder
1.7-liter 4-cylinder
Coupe, sedan
1.7-liter 4-cylinder
Coupe, sedan
1.7-liter 4-cylinder
Two-door hatchback
2.0-liter 4-cylinder
1.3-liter 4-cylinder
1.7-liter 4-cylinder
Are you overpaying for car insurance?
Compare and find out in 45 seconds.
Find Savings!
No long forms. No spam calls. Free Quotes.
4.7/5 App Store Rating, 8,100+ Reviews
Trusted by 1.5+ Million Customers.
rating primary
All models from the DX through the Hybrid model have a fuel tank capacity of 13.2 gallons (50 liters). The GX, however, has a much smaller gas tank that can accommodate up to 8 gallons (31 liters). 
The GX has a special fuel tank that can store the compressed gas under extreme pressure, as well as a fuel regulator. But while the gas tank has a smaller volume, these parts surprisingly take up more space than a conventional gasoline tank—which explains why the GX has only 7 cubic feet of trunk space as compared to 12.9 cubic feet for the rest of the lineup.

How to check your 2003 Honda Civic’s gas tank size

Don’t just take it from us! There are a few ways to check your 2003 Honda Civic’s gas tank size so you never have to worry about running low or running into other unforeseen issues.

Check your owner’s manual

The best, albeit perhaps the most obvious method, for verifying the size of your Civic’s gas tank is by checking the specifications in your owner’s manual. Look for keywords like “fuel tank capacity.” 
If you’ve thrown out your manual or otherwise lost it, you’re in luck—Honda has most of its specifications uploaded to its website. You can look up all the
2003 GX specs
and other vehicle information in the
Honda Civic Owner's Manual

Drive till empty, then fill it up

If you’re feeling a little more adventurous, you can drive until your fuel gauge hits “E”, then see how much gas it takes on a fill-up. This method works best on regular gasoline vehicles, but be sure not to drive too long on empty to avoid damage to your car. 
We do not recommend testing the limits of your GX, however. Overfilling, or even filling your tank up to the brim is not recommended. Underfilling can also cause unnecessary stress on your system. Besides, considering only 1% of gas stations offer CNG, you’ll want to make sure you give yourself ample time to make it to the pump before you run out.

How to save on fuel costs in a Honda Civic

CNG is pretty cheap, but it isn’t necessarily always cheaper than gasoline. Nevertheless, it’s a pretty economical and environmentally friendly fuel option, generally speaking. Gasoline, on the other hand, is incredibly expensive. 
Neither configuration has an abysmal fuel economy, but there are always ways you can improve it and save money while you’re at it. Here are a few tips to follow:
  • Schedule regular service. Skipping maintenance appointments can cause wear and tear on your Civic that can hamper its efficiency, which will cause it to run through more fuel more quickly. 
  • Let up on the pedals. Harsh braking and acceleration will quickly tank your fuel efficiency.
  • Don’t idle. Many people believe it necessary to let their cars needlessly run in place for them to efficiently warm up—this is a myth and wastes precious fuel. You should instead
    ease into driving on cold winter days

How to optimize your Civic’s insurance coverage

Tired of spending a fortune on car-related expenses? You can easily pump up your savings on your
Honda Civic car insurance
with the right tools.
the car insurance super app is designed to optimize your coverage and save you money quickly and without hassle. 
It takes just 45 seconds to download the free app and answer a short questionnaire. Once you provide some basic information, Jerry will compare plans from 55+ leading insurance providers and send the best ones your way. 
Whether you want the same coverage at a lower cost or you’d like to try a new policy or company, Jerry will be there every step of the way. Plus, the average user saves more than $800 each year on their car insurance!
“I used
to get a way better deal for Progressive! My insurance was set to expire the next day and Jerry was able to help me in a matter of seconds.” —Mario B.
Thousands of customers saved on average $887/year on their car insurance with Jerry
This app is great, but the customer service is even better! Not to mention convenient! My husband and I got the lowest rate (much lower than the rates I was finding online through my own searches), quickly, and pretty much all through text message! Thank you so much for a hassle free experience👍
Gabriella R.
Find insurance savings (100% Free)
rating primary
4.7/5 Rating on App Store
Compare Car Insurance Quotes For Free
Jerry automatically shops for your insurance before every renewal. Members save $872/year.
rating primary
Rating on App Store
Start saving money!
12,000+ Reviews
Trusted by 3.5M car owners like you

You might also be interested

Easiest way to compare and buy car insurance

No long forms
No spam or unwanted phone calls
Quotes from top insurance companies
Find insurance savings — it's 100% free