While both motorcycle helmet and car helmet protects our head but their purpose is different due to different kind of dynamics. They may look same but the difference is in the details.
Differential details are discussed below.
1. Fire Resistance: Auto racing helmets are necessitated to be fire proof while motorcycle helmets are not. It is because, a car driver is not likely to be able to escape if a car catches fire. Though these helmets are not entirely fireproof, but rather fire retardant for a period of time. Technology behind fire protection has evolved over time.
# Fire Resistant Lining: Materials are used as fire resistant remains in the inner lining of the helmet, which consist of a single or multiple layers of fire-retardant material. A fireproof helmet basically enables its wearer to withstand the heat and flames caused by an accident.
# Fire Resistant Materials: In automotive industry, fire resistant materials are commonly made of Nylon, Carbon Nit, Nomex or a new material called Conex – a flame-resistant material. Nomex material develops a carbon char when exposed to fire instead of burning or melting. Thus it prevents the spread of the fire and transfer of heat.
# Resistance Checkup: These helmets can lose their fire-resistant properties over time, so be sure to check up. They can also loose its fireproof ability if badly washed or miss handled.
2. Impact Absorption: Shock or energy absorption levels are different on these two helmets. Because a biker could bump and slide on road upon impact while car drivers generally do not slide. Motorcycle helmets are intended to stand just a single big impact while car helmets are made to withstand multiple smaller impacts against the roll cage. Safety of the helmet relies on energy absorption properties. The recent energy absorption material lining includes aluminum honeycomb, honeycomb foam sandwich panel and expanded polystyrene as reinforcement material of the helmet liner. The more absorption properties are enhanced the better safety it provides.
3. Shape and Aerodynamics: Motorcycle helmets are inevitable to be aerodynamic due to obvious reason while car driver sits inside a shield which do not require aerodynamics. Riders are exposed to the elements so these helmets are designed to absorb various level of continuous impact. They need perfect aerodynamic designs for stability and padding for grip. While auto racing helmets do not need to concern shape and aerodynamic.
4. Ventilation and Noise reduction: Auto racing helmets are not much concerned about ventilation and noise reduction, which is self-explanatory. On the other hand motorcycle helmet needs more vent for comfort and better padding for noise reduction. Full-face helmets are quieter than so called skull cap or half-helmets.
5. Visibility: Visibility is very much important when it comes to any kind of racing. Motorcycle helmet needs wider visibility than car helmet because motorcycle is often used in public road. But car racing helmets are only used on tracks where you just have to look forward.
6. Structure and Weight: Sitting posture is different in these two rides so their helmet structure is differently built. Weight of helmet may vary depending upon size. Full-face motorcycle helmets range from approximately 1400 to 1800 grams. Bike helmet primarily is lighter than auto racing helmet.
7. Rating and Certification: Generally auto racing helmets are ‘’SA’’ certified which stands for ‘’Special Application” by Snell Memorial Foundation. The current standard is SA2020. Snell memorial Foundation is a nonprofit organization founded in 1956 and named after William Pete Snell who died in a racing accident. After his death, his friends, doctors, scientists got together to research, develop and improve effectiveness of helmets. When it comes to motorcycle helmet, there is a Snell Standard too and latest standard is M2020. There are similarities of Snell’s method of testing and certification with those of UN ECE and DOT. But there are some differences too which are tougher to pass.
8. HANS Device: HANS Device is a safety device in motor sports. It is a ‘Head and Neck support device’ works as a head restraint. It reduces head and neck injuries and skull fracture. Generally made of carbon fiber reinforced polymer. Car helmets often require provision for use of a HANS device but motorcycle helmet do not.
9. Maintenance: Particle of materials used in making of those two helmets are quite different because they aim to absorb different type of energy. Plainly different materials need different type of maintenance such as cleaning, storage, resistance checkup. So following user guidance of an individual helmet is highly advised.
Okay, some certain motorcycle helmet may be accepted for auto racing if they are certified by Snell. But please don’t mix the two, as you don’t use car engine oil in your motorcycle engine. So don’t wear car racing helmet while riding your motorcycle and vice versa.