When Should You Buy Premium Gas?
Buy premium gas only when your car's manufacturer requires it, not just recommends it. Check your owner's manual or the inside of your fuel door for fuel grade requirements. Most everyday cars run perfectly fine on regular 87-octane gas and see no benefit from premium fuel.
The Key Difference: Octane Level
Regular gasoline has an 87-octane rating, while premium ranges from 91 to 94 octane. Higher octane resists "engine knock," which happens when fuel ignites at the wrong time in your cylinder. Engines with higher compression ratios (mostly high-performance cars, turbocharged vehicles, and luxury models) need premium to prevent knock and perform as designed.
If your car only recommends premium but doesn't require it, you can safely use regular gas. You might notice slightly reduced power under heavy acceleration on extremely hot days, but everyday driving stays virtually identical.
Real-World Savings From Using Regular
Using regular gas instead of premium saves money when your car allows it:
| Fuel Economy | Annual Savings |
|---|---|
| 30 mpg | $339 |
| 25 mpg | $407 |
| 20 mpg | $509 |
| 15 mpg | $678 |
These savings add up fast without any noticeable difference in how your car performs on normal commutes.
When Premium Is Actually Required
Sports cars, performance sedans, turbocharged engines, and many luxury vehicles require premium because their engines operate under higher pressure and temperature. Using regular gas in these vehicles risks engine knock, which can damage the engine over time and reduce performance. If your manual says "required," don't skip it.
How to Check Your Vehicle
Look for fuel grade guidance in three places: your owner's manual, the inside of your fuel door, or on Sidekick's vehicle database. Many vehicles show "premium recommended" rather than "required." That recommendation gives you a choice.
The Bottom Line
Don't pay extra for premium unless your manufacturer requires it. If your car recommends it but doesn't require it, regular gas works fine for most driving. Check your specific vehicle's requirements and save money at the pump.