Updated April 5, 2026 — Prices updated regularly from EIA data
$3.87
Premium Gasoline (91-93 octane) per gallon
About Premium Gasoline in Rapid City
Premium gasoline (91-93 octane) costs $$3.87 per gallon in Rapid City, South Dakota today. High-performance and luxury vehicles depend on premium's higher octane rating to prevent knock and maintain the performance they're engineered to deliver.
When to Use Premium Gasoline
Best for: high-performance engines
Vehicle types: luxury and performance vehicles
Fuel Price Comparison in Rapid City
Fuel Type
Price
vs. Premium Gasoline
Octane
Regular Unleaded
$3.10
$-0.77
87
Premium Gasoline THIS PAGE
$3.87
—
91-93
Diesel Fuel
$4.20
+$0.33
N/A
Premium Gasoline in Nearby Cities
Fuel Up Your Collection While You Save on Gas
American patriotic collectibles. Limited edition and built to last — just like your savings at the pump.
For vehicles designed to use Premium Gasoline, using the correct grade maintains engineered fuel economy. Upgrading from regular to premium in a regular-fuel car produces no economy improvement. Using regular in a premium-required car may reduce fuel economy slightly.
National Premium Gasoline prices average ${natPrice} per gallon. Rapid City's current price of $$3.87 is {comparison} the national average. Regional refinery access and state tax differences drive most of the variation.
TOP TIER certification means the fuel exceeds EPA minimum detergency standards. Studies suggest TOP TIER fuels meaningfully reduce engine deposits vs. minimum-standard fuels. Most major brands (Shell, Chevron, BP, Costco) are TOP TIER certified.
Mixing grades is generally fine in practice — your engine's knock sensors will adjust timing accordingly. If your vehicle requires premium and you add some regular, no immediate damage occurs. Consistently running below the required octane in a performance engine is not recommended long-term.