Ethanol or gasoline?
Type both prices to learn whether ethanol or gasoline is cheaper today.
70% rule of thumb for Brazilian flex-fuel drivers.
How to use this tool
- Enter the price per liter of ethanol.
- Enter the price per liter of gasoline.
- Read the ratio and the recommendation.
- Try a different ratio threshold for your car if you know it.
Typical use cases
- Filling up on a road trip with mixed prices.
- Comparing two stations in the same city.
Limits & caveats
- Assumes the standard 70% efficiency rule of thumb.
- Does not consider distance to the station or loyalty discounts.
Frequently asked questions
What is the 70% ethanol rule in Brazil?
Flex cars use about 30% more ethanol per km. Ethanol is usually cheaper when its price per liter is below 70% of gasoline.
How do I know if ethanol is worth it today?
Divide the ethanol price by the gasoline price. If the result is below 0.70 (70%), ethanol is typically the better choice.
Does the 70% rule work for every flex car?
It is a market average. Some models differ; use this as a quick guide and adjust if you know your car's ratio.
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Brazilian flex-fuel cars consume ethanol about 30% faster than gasoline, so ethanol is only a deal when its price is below ~70% of the gasoline price. This calculator runs the comparison locally.