How to Use the Run-Flat vs Regular Tire Calculator
Run-flat tires let you keep driving a short distance after a puncture without a spare, which is a real safety advantage — but they cost noticeably more upfront and their stiffer sidewalls affect ride comfort and fuel economy. This calculator combines the price difference and the fuel penalty to compare 5-year total cost.
The calculation assumes both tire types last about 25,000 miles, and applies a roughly 3% fuel economy penalty for run-flats due to their added rolling resistance from thicker sidewalls. Actual results vary by tire brand, driving style, and road conditions.
On raw cost alone, run-flats often look like the worse deal. But the ability to reach a repair shop instead of being stranded roadside after a flat, plus the trunk space and weight savings from skipping a spare tire, are real benefits this cost comparison doesn't capture.
Frequently Asked Questions
Run-flat tires have thicker, stiffer sidewalls that let you keep driving a short distance after a puncture, but the added weight and rolling resistance typically increase fuel consumption by about 2-3% versus regular tires.
Correct. Run-flats are designed to be driven roughly 50 miles at 50 mph or less after a puncture, so many vehicles skip the spare tire entirely — but the tires themselves cost more and ride noticeably firmer.