I happen to have a 300 TD in the shop and the nozzle aperture isn't any bigger than the VW. They flow more fuel and that's the supposed hi-po "tuner" set-up but the VW shield hole is more than sufficient to accommodate that. Both nozzles have flat faces and mount the same way. I had no leakage. I'd like to know more about the spray pattern. Lots of discussion about other nozzles but I don't remember anything about differing patterns, just volumes. Heat shields-same thing.