Start with the exact question
A figure that applies to private transport in Germany may not apply to a ferry, another country or a workplace. Each guide therefore identifies the relevant country and use case wherever possible.
Preferred sources
- legislation and official authorities
- public technical services
- recognised testing organisations and motoring clubs
- manufacturer data sheets and manuals
- specialist publications as supporting context
Retailer descriptions and forum posts can point to a topic, but they are not used as the only basis for a legal or safety-related statement.
Law and practical advice are different
A legal maximum does not tell you what is sensible to carry in everyday use. The guides distinguish between what may be permitted, what a recognised organisation recommends and what is practical for the actual vehicle or task.
Product comparisons
Product pages use article numbers, EANs, material, dimensions, empty weight, spout information and approval details from manufacturer documents. These specifications cannot show long-term tightness, smell, ease of pouring or durability in daily use.
Corrections
Rules and product documents can change. Corrections or updated source links can be sent through the contact page.