Gallons per fill is rarely stated nowadays.

Per the model number, your machine dates to 2004. The serial number would clarify the year of manufacture.

It's a typical direct-drive Whirlpool washer. I do find some info dating to the late 1980s and early 1990s that states between 17.3 and 21.7 gals for a full fill, depending on the capacity of the machine -- large or super. So a complete wash/rinse cycle may be on the order of 34.6 to 43.4 gallons, plus a couple more gals for the spray rinses. Depends on whether the tub design, load capacity, and max fill level remained consistent over the course of years.

We had a direct-drive Whirlpool ca. 1995 that was the XL-capacity, before buying the FL last year. I always wondered how many gallons it used. Now I know I am definitely saving on water!
Thank you for posting the info, @dadoes.

The 18lb belt-drive models (until a revision on the tub size in the late 70s or early 80s reduced it a little) took much as 27 gallons for a full fill. The Perm Press cycle with two half-drain/refill cooldown sequences could pull more than 81 gallons total.

27 galllon-fill is still a lot of water. I never used the Perm-Press, thank goodness, especially now that I know the water usage. I only used the Normal and Delicate cycles and adjusted water level as needed.