E Torque equipped trucks standard is 23 gallons fuel tank, unless Optionally ordered and larger tank put in. Most Hemi's unless Optional equipment have 26 gallon tanks. But OP should be getting a lot more than 230 miles to a tank. Last I saw, most Hemi's get close to 20 MPG more/less on Highway.
OP, if U R reading the idiot gauge that gives ETE, than U will never get a true MPG range. U need to hand calculate. But even the idiot readouts get close, sometimes. But I find even on my Hemi, after fillup the ETE range is usually shown as 335 to 350 miles, and that is totally wrong. It is not even close. (Based on Highway, not local driving).
Math says: 20 mpg: 26 gallon tank gives U appx 520 miles, but of course how U drive, maintain, speeds achieved, wind, all that applies. This would be steady highway, not stop and go in town. U will find your in town mileage, be between 13-17 ish MPG. I get almost 17 running around town if not driving like on a "turkey trot".
You just cannot believe a fuel gauge that reads low anyway like 2-3 gallons. But OP, if you get close to the Idiot light coming on, as in low fuel, best fill up. And never run these things dry.
All above IMHO.