San Marcos Average Gas Price
| Regular | Mid-Grade | Premium | Diesel | E85 | |
|---|---|---|---|---|---|
| Month Ago Avg. | $3.3 | $3.46 | $3.93 | $4.01 | $2.85 |
Highest Recorded Average Gas Price In San Marcos Year to Date
| Price | Date | |
|---|---|---|
| Diesel | $4.07 | 10/10/26 |
| Regular | $3.3 | 09/10/26 |
Top 10 Gas Stations & Cheap Fuel Prices in San Marcos
Texaco in San Marcos (15610 Texas Hwy 123)
15610 Texas Hwy 123, San Marcos, Texas,
$3.00
Oct 24, 2026
0¢ Cashback
Murphy USA in San Marcos (1201 Highway 80)
1201 SH-80, San Marcos, Texas,
$3.59
Oct 24, 2026
0¢ Cashback
Exxon in San Marcos (1103 SH-80)
1103 SH-80, San Marcos, Texas,
$3.59
Oct 24, 2026
0¢ Cashback
Sunoco in San Marcos (1903 N IH-35)
1903 N IH-35, San Marcos, Texas,
$3.64
Oct 24, 2026
0¢ Cashback
Valero in San Marcos (1550 IH-35 N)
1550 IH-35 N, San Marcos, Texas,
$3.64
Oct 24, 2026
0¢ Cashback
Valero in San Marcos (1002 SH-80)
1002 SH-80, San Marcos, Texas,
$3.79
Oct 24, 2026
0¢ Cashback
Exxon in San Marcos (339 N Guadalupe St)
339 N Guadalupe St, San Marcos, Texas,
$3.89
Oct 24, 2026
0¢ Cashback
Exxon in San Marcos (1636 Aquarena Springs Dr)
1636 Aquarena Springs Dr, San Marcos, Texas,
$3.94
Oct 24, 2026
0¢ Cashback
Murphy USA in San Marcos (1201 Highway 80)
1201 Highway 80, San Marcos, Texas,
$3.96
Oct 24, 2026
0¢ Cashback
Valero in San Marcos (2050 S IH-35)
2050 S IH-35, San Marcos, Texas,
$3.99
Oct 24, 2026
0¢ Cashback
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Gas Data Methodology
The fuel prices published in this guide are based on the results of research completed by Way.com’s data team. Using a mix of external and internal data, we analyzed millions of prices across U.S. ZIP codes and globally.