75L Diesel Tank

The tank can not take 75L in operation.
If installed on a vehicle, (as suggested) the breather allows fuel to leak out each time the fuel moves there. This cause a wetted mess around the tank and onto the vehicle. The tank also drops in volume if in a horizontal position, resulting in a reduction in fuel volume to 60-65L. The bright yellow color suggests a fuel tank which invites thieves to the fuel. I have to cover it with a blanket and impose it to ve a water tank to reduce the risk of fuel theft. The tank is in dimensions still higher than any roofrack and thus cause wind resistant drag during driving. I installed a deflection sheet to reduce this.
My perception is that the designers do not use the tank and thereby design not from experience, which results in such hassles.
If the tank was fitted with splash resistant baffle plates inside the fuel, would move better during driving and the tank woul retain its shape allowing better air movement and fuel capacity.
Tge air calve needs to be an actual airvalve that prohibits liquid passing. A cladding bag could help with obscuring the content and improving the exposure resistance.

Great products bougbt 2 after I had 2 petrol tanks