Ok I'll clear this one up once and for all, as I've just scanned the VW 'Specification and equipment 1990 model year' (issue January 1990) which shows the performance figures for both the 8v and 16v GTi's:
Performance: GTi GTi 16V
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Top Speed, mph/Kph 119/191 129/208
Acceleration, secs 0-50 mph 6.5 6.0
Acceleration, secs 0-60 mph 8.3 7.9
