The V8 Triumph saloon is very highly geared and cruising at ahem, motorway speed returned 35 MPG on this 2000 mile trip. It's not the original engine but a £150 scrapyard special from an auto SD1 mated to the SD1 manual 5 speed box - complete with handmade gear lever protruding out of the floor rather than the center console as it should! The gear change is truly awful. like a welly in a cow pat. We slapped the original twin SU's on it and a set of headers mated to a single large bore exhaust system but other than that it was "stock". It was very lazy, crap up hills, I think it has a PI final drive.
J