For our two week Big Bend trip (see post Trip Planning for Weekenders), we started with a full tank in the truck.  We towed the Jeep.  However, we did change our route as a result of road construction.  On the way to Big Bend National Park I drove much faster than usual setting the cruise control a sliver above 75 MPH on I-10 West once we got out of San Antonio and past Boerne, Texas.  Also, side and headwinds were an issue which is common for this part of Texas and this time of year.  The fuel mileage suffered as a result.

I dialed down the cruise control between Big Bend National Park and Davis Mountains State Park to 65 MPH on TX-118.  On the way home from Davis Mountains State Park on US-90 East I stuck to 65 MPH as well.  Mileage improved but not as much as I had hoped.  The winds were ever present on the way home as they were on the way to Big Bend.

• San Antonio I-10 and FM-1516
  • $2.489 per gallon Diesel fuel
• Fort Stockton I-10 and US-385
  • $2.939 per gallon Diesel fuel
  • San Antonio to Fort Stockton 8.34 MPG (ouch!)
• Study Butte TX-118
  • $3.109 per gallon Diesel fuel
  • Fort Stockton to Big Bend National Park to Study Butte 9.12 MPG
• Marathon US-90
  • $3.009 per gallon Diesel fuel
  • Study Butte to Davis Mountains State Park to Marathon 11.77 MPG
• San Antonio I-10 and FM-1604
  • $2.799 per gallon Diesel fuel
  • Marathon to home 9.72 MPG

Gas mileage improved on the way home for two reasons.  First and foremost, I slowed down.  Secondly, the overall elevation change between Davis Mountains State Park and home is roughly 5000 feet.  Going downhill, on average, really helps out fuel efficiency.

You may have noticed the dramatic fuel price differences between San Antonio and the other stations.   Fuel prices are always higher in remote out-of-the-way places.  Also, I filled in San Antonio outside of the holidays (Veteran’s Day and Thanksgiving).

• trip planning