Flex-fuel guides & calculators

Savings

How much does E85 actually save you? Start keeping score

The per-fill math, why guesses are worthless, and the new fill-up log that keeps a lifetime total for you.

Is E85 actually cheaper than gas?

The per-gallon price is only half the story. Here's how to know if E85 really saves you money — using cost per mile, not the pump sticker.

How to find E85 stations near you

Where E85 hides, why generic gas apps miss it, and how to find the cheapest verified E85 around you — including by state.

How to mix E85 with premium (E30, E50)

The exact math to blend E85 with 91/93 to hit a target ethanol % — and why the real pump ethanol content changes the recipe.

Your "E85" probably isn't 85% ethanol

E85 is legally 51–83% ethanol and drifts by season. What that means for your octane, your MPG, and your blend.

What cars can use E85?

How to tell if your car is flex-fuel, common FFV models, and what happens if you put E85 in a regular car.

E85 vs 93 octane

Which is better for power and cost — and why a lot of tuners just blend the two.

Does E85 damage your engine?

Safe by design in a flex-fuel car — a real risk in a non-FFV. The honest breakdown.

E85 gas mileage: how much MPG do you lose?

Expect 15–27% fewer MPG — and why E85 can still be cheaper per mile.

E85 horsepower gains

How much power E85 really adds on a boosted, tuned engine — and what you need first.

E85 in winter

Why winter "E85" isn't 85%, how it affects cold starts, and what to do.