It's not that Land Rover thinks the North American market is nothing but soccer moms, it's that it never offered a diesel LR4 in North America. I assume by "vehicle upgrade" you mean the SC V6 engine instead of the V8 engine, but, in this context, it makes no difference whatsoever. Land Rover for some reason felt that the gas engines needed bigger brakes than the diesel engines, so all gas engine LR4's--no matter the model year--only had 19" wheels from the factory as the Land Rover 18" wheels don't fit over the gas LR4's brake calipers. Land Rover only offered gas engines in North America. Hence, there was never a North American LR4 that came with 19" wheels.