How to Use the Premium vs Regular Gas Cost Calculator
Premium (high-octane) gasoline costs more per gallon than regular, but whether it's actually worth paying for depends entirely on your engine and how you drive. Some drivers pay extra out of habit without knowing if it changes anything for their specific car.
This calculator takes your annual mileage and the price and MPG for both regular and premium gas, then compares total annual fuel cost for each. If premium genuinely improves your fuel economy or performance enough to offset the higher price, the extra annual cost shown here will be smaller than the price gap alone would suggest — or even negative.
If your owner's manual says premium is "recommended" rather than "required," most modern engines with knock sensors will run fine on regular with little to no measurable difference in economy or performance. If premium is "required" for a high-compression or turbocharged engine, using regular can actually hurt performance and, over time, engine health — so the comparison matters less there than simply following the manufacturer's spec.
Frequently Asked Questions
In an engine the manufacturer requires or recommends premium for (usually high-compression or turbocharged engines), it can prevent knocking and preserve performance. In a standard engine designed for regular, the difference is usually negligible or nonexistent.
In the US, premium typically runs about $0.30 to $0.60 more per gallon than regular, though the gap varies by region, brand, and time.