It isn't so much about the hard numbers as the fact that a manual transmission requires much more involvement from the driver and improves the perception of performance as well as making the vehicle more fun in general to operate. For the record, I hate automatic transmissions and only buy vehicles that have them because those models weren't made with manuals.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.