* Ethylene glycol is the most common type of antifreeze and is safe to use in most cars, including antiques. However, it is toxic and can cause health problems if ingested, so it is important to take precautions when handling it.
* Propylene glycol is a less toxic alternative to ethylene glycol and is safe to use in antique cars. It is also biodegradable, making it a more environmentally friendly option.
* Methanol is a type of alcohol that can be used as antifreeze. However, it is highly flammable and can cause health problems if ingested, so it is important to take precautions when handling it.
* Glycerin is a non-toxic, biodegradable alternative to ethylene glycol and propylene glycol. However, it is more expensive and may not be as effective as other types of antifreeze.