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If someone is considering a K04 vs K03 car regarding fuel economy, I think it may be more appropriate to buy a completely different kind of car and one which delivers serious fuel economy. GTI's/Ed30's etc are designed to be enjoyed without too much concern about the mpg.
I beg to differ on this one Robin
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The FSI technology (direct injection etc) has been designed in to aid fuel economy and reduce emissions (among other reasons)
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If you think back to the original MK1 GTI, people loved it for its "reasonable fuel economy" which is why it was such a hit - performance AND economy
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Upon talking to R-Tech Nick, he explained (in more detail than I can understand
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) that the TFSI basically runs super lean on light throttle (creating loads of NOX for the CAT to remove) for long periods. . . All in the name of fuel economy
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which is why quite a few of us have managed 40+mpg on those boring motorway runs
Graeme