Terms of Use

These Terms of Use govern your use of the Lambda website and calculators (the "Service"). By accessing or using the Service, you agree to these terms. If you do not agree, do not use the Service. You must be at least 18 years old to use the Service.

1. Off-road and competition use only

The Service is intended solely for off-road, competition, and racing applications, and for vehicles that are not subject to emissions regulations. It is not intended for, and must not be used to plan modifications to, emissions-controlled vehicles operated on public roads.

2. Informational tool only — not advice, not a service or device

Lambda is an informational calculator. It computes estimated fuel properties from published data and standard formulas. It does not modify, flash, tune, or connect to any vehicle, engine control unit, or emissions control system, and it is not a tuning service, a defeat device, or a part or component for any vehicle. Its output is not engineering, mechanical, or professional tuning advice and is no substitute for testing, measurement, and judgment by a qualified tuner on your specific setup.

3. Estimates — do not rely on them for tuning decisions

All figures the Service produces — including stoichiometric AFR, octane (RON/MON/AKI), density, and injector flow — are estimates and may differ from your actual fuel and engine. Never use them to set ignition timing, boost, or fueling without independent verification using knock detection, a wideband oxygen sensor, and/or a dynamometer. Octane that is over-estimated, or pump "E85" whose real ethanol content differs from what you entered, can cause detonation that destroys an engine in seconds. You are responsible for verifying every number.

4. Assumption of risk

Blending fuels and modifying or tuning an engine are inherently dangerous activities that can cause, among other things:

• severe engine, drivetrain, or vehicle damage;
• fire, explosion, exposure to toxic or corrosive substances;
• serious personal injury or death.

You assume all risk arising from your use of the Service and from any action you take based on its output.

5. No warranty

The Service is provided "as is" and "as available," without warranties of any kind, express or implied, including but not limited to accuracy, fitness for a particular purpose, or non-infringement. We do not warrant that any calculation is accurate, complete, or suitable for your purpose.

6. Limitation of liability

To the maximum extent permitted by law, in no event will the operator of Lambda be liable for any indirect, incidental, special, consequential, or punitive damages, or for any loss of property, profits, or data, arising out of or related to your use of (or inability to use) the Service, even if advised of the possibility of such damages.

7. Indemnification

You agree to indemnify, defend, and hold harmless the operator of Lambda from and against any claims, damages, losses, liabilities, and expenses (including reasonable legal fees) arising out of or related to your use of the Service, your reliance on its output, any damage to property or injury to any person, or your violation of these terms or any law.

8. Regulatory compliance

You are solely responsible for complying with all applicable laws and regulations, including the U.S. Clean Air Act and any state or local emissions laws. The Service is not designed or intended to defeat, bypass, or tamper with any emissions control system. Tampering with emissions controls on vehicles used on public roads is illegal, and there is no off-road or competition exemption for vehicles originally certified for road use.

9. Governing law

These terms are governed by the laws of Brazil, where the operator is based, without regard to conflict-of-law principles. Nothing in these terms limits any non-waivable rights you may have under the mandatory law of your place of residence.

10. Billing, subscriptions, and refunds

Lambda Pro is sold through Paddle.com, which acts as the merchant of record for your purchase and handles payment, billing, and applicable taxes. Pro is offered as an annual subscription ($29/year) or a one-time lifetime purchase ($49). Annual subscriptions renew automatically each year until cancelled; you can cancel at any time before the renewal date to avoid the next charge.

We offer a 14-day money-back guarantee: you may request a full refund within 14 days of any purchase, for any reason, by contacting us through the site or Paddle. Refunds are issued to the original payment method.

11. Changes

We may update these terms or the Service at any time. Continued use after changes take effect constitutes acceptance of the updated terms.

12. Contact

Questions about these terms can be sent through the site contact.