On my V5 the following are totally blank.
V7 CO2 (gm/km
S.1 Number of seate including driver
J. Vehicle category
K Type approval number
P.2 Max reference power
F.1 Max permissible mass
G. Mass in service
[ ignore trailer info]
[V1-V5 All emissions info are blank]
Even Transport for London's LEZ contractors no longer rely on DVLA information, as did the previous contractor and will accept any evidence submitted to them directly.
DVLA will put on the form whatever the Dealer or Owner tells them, as long as they get the right tax. They do not know one end of a vehicle from another.
For technical details it would be better if DVSA(ex VOSA) handled the system as they know vehicles.