We use U-400 which has a "safe drive away time" of 2 to 4 hours (in extreme temps) in most temperature and humidity ranges and is comprable to SIKA. U-400HV is OEM-approved and certified to meet FMVSS 212 windshield retention and FMVSS 216 roof crush standards.
Most installers use the cheapest urethane adhesive available (progrip) and curing time for that is as high as 8 to 24 hours depending on the temperature and humidity.
This adhesive is perfectly fine once it's dried but it literally tales 4 to 10 times longer than U-400 or SIKA.
This is not to be confused with U-418 or U-428 which are cheaper versions and can take as long as ProGrip or other cheaper adhesives. This wouldn't be such a problem but many of the installers tell you that you can drive away after only one hour or worse drive away right after the installation.
