Terms of use

1. What the service is

A combustion-engine simulator that runs in your browser, plus the writing around it. Every real engine in it is free: no account, no download, nothing to buy to run any of them. Building your own engine is a paid plan, described in section 5. Use the free part for learning, in a classroom, in a video, or in a forum argument; you do not need our permission. Advertising and that plan pay for it.

2. Your account

You need one only to save engines, to subscribe, to share an engine you built, or to be written to. You must be at least 16 to hold one, and under 18 with a parent’s or guardian’s agreement. One person per account: keep the email address you sign in with under your control, do not hand the account to anyone else, and tell us if you think someone has got into it. Until you do, you answer for whatever anyone does with it.

We use the address to run the account, and, unless you opt out, to tell you about the simulator now and then; the privacy policy says what we send and how to stop it. We may close an account that breaks these terms, that is used to abuse the site or other people, or that nobody has signed into for two years, after emailing first; we never close a paid-up Pro subscription for inactivity. Write to us and we delete your account and everything in it.

3. What it is not

Do not use anything here to build, tune, or make a safety judgement about a real engine. We solve the figures from a model. Nobody measured them on a dynamometer or copied them from a manufacturer, and a model agrees with reality only where somebody checked it. Exhaust temperature is approximate today, and fuel consumption reads high for diesels and low for petrol engines. We will fix both, and the numbers will move.

Where we built a preset to a real engine’s published geometry, the roster says which figures agree and claims nothing further.

4. Acceptable use

Please do not:

• attack the site, or reach for data and systems you are not meant to;
• scrape it in a way that degrades it for other people, or republish it wholesale as your own;
• click adverts yourself or arrange for others to. That is fraud against the advertiser, and it costs us the account;
• send abuse, spam, malware or other people’s personal data through the forms;
• present the simulator as endorsed by an engine manufacturer;
• share an engine whose name or notes carry personal information, links or abuse, or whose name does not describe the engine.

Ordinary things are fine and welcome: link it, screenshot it, show it to a class, put a dyno pull in a video.

5. The Pro subscription

Builder Pro unlocks the engine builder, unlimited saved engines, priority for your feature requests and a reply to your feedback within two working days. It costs $12 a month, $27 every three months, $42 every six months or $60 a year, before any tax that applies where you live, and renews at the end of each period until you cancel. Builder AI adds the AI engine builder to everything in Pro for $27 a month, $57 every three months, $90 every six months or $144 a year on the same terms; moving from Pro to Max charges the difference for the rest of the period you are in. Buying either means agreeing to these terms and to Polar’s buyer terms shown at checkout.

• Who you pay. Polar Software Inc. is the merchant of record: it takes the payment, issues the invoice, works out the tax and holds your card details. We never see the card. Polar’s own terms apply to the payment itself.
• Cancelling. Cancel any time from the billing portal under your account menu. You keep Pro until the end of the period you paid for, and we charge nothing after that.
• Refunds.
  • Fourteen days from a first purchase. Write within fourteen days of a first purchase and we refund it, less a 5% processing fee, whether or not you used the plan.
  • No fee when the mistake is ours. A duplicate charge, a wrong amount, or a plan you paid for and could not use because of us: refunded in full.
  • Where the law gives you more, you get it. A consumer in the EU, the EEA or the UK can withdraw within fourteen days of a first purchase and gets it back in full, with no fee. The same holds anywhere else whose law gives you more than this section does.
  • Renewals, upgrade charges, and anything after fourteen days: we decide case by case, and we lean towards refunding. The fee applies.
  • How to ask. Email hello@realenginesimulator.com from the address you paid with, with the payment date, the invoice number from Polar’s confirmation email and the reason you want the refund. That address is the one that handles refunds.
  • What happens next. The refund ends the plan that payment paid for, straight away. Polar returns the money to the card you paid with; your bank decides how long it takes to show.
• Prices. We may change them; a change reaches you only at your next renewal and only after we have told you.
• A failed payment. If Polar cannot take a renewal it retries and emails you; Pro pauses until a payment succeeds, and your engines stay where they are. If you dispute a charge with your bank rather than with us, Pro pauses until the bank settles it.
• Support. “Within two working days” is a promise about replies, not a service level for the simulator, which stays as it is under section 9.
• If you stop. Nothing is deleted. The builder and your garage close until you subscribe again; share links you already sent keep working. Engines you shared to the community are hidden while you are not subscribed, and come back if you subscribe again.

6. What you send us

A bug report, a partnership enquiry or an article for the blog stays yours. You give us permission to use it to run and improve the site: to quote it, to act on it, and to publish a guest article with your name on it. Send only what you have the right to send. We may decline or remove anything without giving a reason.

An engine you share with the community stays yours too. You let us show it, its name, your notes and your builder handle to subscribers while it is listed, and subscribers can open and run it on the site. We review every submission before it appears, and may decline or remove one. You can withdraw yours from your garage, or by writing to us.

7. Intellectual property and engine names

The simulator, its physics code, the artwork and the writing belong to us or to whoever wrote them. Use it personally, use it in a classroom, quote a passage with a link. Do not republish substantial parts as your own; ask through the partnerships page instead, and the answer is usually yes.

Manufacturer and engine names appear here to say which engine we modelled, and for nothing else. All trade marks belong to their owners. We are not affiliated with, endorsed by, or sponsored by any vehicle or engine manufacturer, and we use no manufacturer logos or trade dress anywhere.

8. Adverts, links and availability

Adverts come from third-party networks; we do not choose what they show. Links out go to sites we do not run. We are responsible for neither, and the privacy policy covers what the advertising means for your data. You get the site as it is, when it is: we may change it, remove parts of it, or stop running it without notice. The physics model keeps changing, and the changelog records what moved and when.

9. Warranties and liability

To the fullest extent the law allows, we provide the site “as is” and “as available”, with no warranty that it is accurate, complete, uninterrupted or fit for any particular purpose. We are not liable for lost profit, lost data, business interruption, or any indirect loss, and in particular not for any damage, cost or injury from acting on a figure the simulator produced. If you have paid for Pro, we cap what we owe you for anything arising from it at what you paid us in the twelve months before the claim. Nothing here limits liability for death or personal injury caused by negligence, for fraud, or for anything else that cannot lawfully be limited, and if you are a consumer you keep the rights the law gives you regardless.

10. Governing law and changes

These terms are governed by the law of Lithuania and its courts have jurisdiction; a consumer elsewhere in the EEA keeps the mandatory consumer protection of the country they live in, and may also use the European Commission’s online dispute resolution platform. We may update this page. The date at the top says when it last changed. We announce a change that matters on the site and, to account holders, by email before it applies, and a change to what Pro costs or includes reaches you only at a renewal. Questions: hello@realenginesimulator.com.