Finally worked my way down to "0 miles" on this transition tank on Friday and had to fill up yesterday.
Given that the 40 gallon fill is going to be significantly more than the 26 gallon fill in the standard factory tank and that I have to deal with most gas stations $100 automatic shut-off on credit card purchases, I decided to look for the best price for fuel in lieu of my closest Mobil station. Kinda baffled by the wide spread in diesel fuel price is my area -- from a low of $2.87/gal to a high of $3.59/gal according to GasBuddy, but given this info, I found a Valero station not too far out of my way that had diesel for $2.89/gal for cash or credit.
Before I pumped any fuel, I added an 8 oz. bottle of both Stanadyne Performance Formula (covers 25 gallons) and
Stanadyne Lubricity Formula (covers 15 gallons) At the $2.89/gal price for diesel, I managed to get just under 34.5 gallons before I hit the automatic shut-off limit, so didn't fill the 40 gallon tank quite 100% full but pretty close, which resulted in 894 DTE miles (screen capture below) on the IPC. If I started the pump again or could find a better price for diesel, I should be able to get over 900 miles for DTE with the Titan XXL 40 gallon replacement tank for F150s w/5.5' bed. With these ranges, I am under the 999 max mile limit that
mentioned earlier in this thread.
I had some unexpected highway mileage due to having to travel home for a funeral this past Monday, so I think without any unexpected trips, I should be close to a fill-up once/month = pretty cool in my book! Although the diesel fuel economy is ~20-25% better than my 2015 F150 Platinum 5.0L V8, it sure feels like I visit the gas station a lot less now with the 2018 F150 PS 3.0L V6 Diesel, and I am spending a lot less at the pump. At once/month fill-ups, my case of 24 bottles Stanadyne Performance Formula and case of 24 bottles of Stanadyne Lubricity Formula should last ~2 years.
If anyone has any questions with either of the Titan tank replacement options,
and I have recently installed the 40 gallon tank for the 5.5' bed and
installed his 48 gallon tank on his KingRanch w/6.5' bed about 6 months ago.