I always wondered why American cars are so inefficient. Seems such a waste of your significantly cheaper gas :) I drive an Opel Astra H 1.7 CDTI and I can get up to 50 mpg (4.7 l/100 km) on the highway, and I never dip under 40 mpg (5.8 l/100km) even when doing a lot of city driving. I understand that my car is comparatively somewhat smaller (1200 kg) and underpowered (100 hp), yet I can't imagine needing more horsep…
I've just come from a trip around the US national parks, and noticed something similar. I rented the cheapest, smaller car that I could, which was a 2015 Dodge Dart which would probably be about mid-range in the UK. It claimed 30 miles / gallon for optimal driving. Converting, that's 36 miles / UK gallon. I don't actually own a car at the moment, but for a few years I owned a 1995 Peugeot 106 which normally got just…
For comparison, I own a 2012 Chevrolet Sonic (known as the Aveo overseas) with the 1.4 L turbo engine (rated 138 HP). I have a mostly-highway commute and my lifetime average MPG(-US) is 38.0. On a long road trip I take once per year I have gotten over 50 MPG (measured by dividing the fuel I consumed on the trip by the distance I traveled) despite the vehicle only being rated at 38 MPG highway by the EPA. You can easily exceed the EPA highway rating on most cars if you accelerate gently and don't drive too much faster than 70 MPH.