Welcome back to Guy’s Garage! Today I put my 2010 Porsche Cayenne (non-turbo) to the test on a real 28-mile California drive to answer one simple question:

Can you actually improve MPG just by changing tire pressure?

With gas prices hitting $6/gallon here in California, every bit counts. So I ran a before-and-after test—comparing normal tire pressure vs higher PSI—to see if there’s a real difference in fuel economy.

Results might surprise you…

In this video:

Real-world MPG test (city + freeway)
Tire pressure experiment explained
Porsche Cayenne driving impressions
Hidden features & quirks (speed limiter, settings, etc.)
What it’s like owning a high-mileage Porsche

Final result:
I went from about 16 MPG → 19 MPG (≈ +3 MPG gain)

That’s roughly a 5% improvement just from tire pressure alone.

⚠️ Note: Higher tire pressure can affect ride comfort and safety—always stay within safe limits.

If you’re trying to save money on gas, this might be one of the easiest tricks out there.

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