[kafer65]

We have a new company car that has cylinder deactivation on the already thrifty for its size V8. I used to own a 2000 model that would get 18.5 mpg without doing any eco-driving hwy. I have a service route that is 74.4 miles round trip and includes a long climb with 500 foot elevation change but is mostly highway. I thought I'd try to drive this rig much like I drive my Mazda to see what it would do. DFCO and selective AC use but try not to be in the way. I managed to keep the "4V" deactivation mode at hwy speed and even in moderate climbs maintaining indicated 22mpg most of the time. Where my Mazda gets 22 mpg in the hard climbing sections it would revert to V8 mode and get 14. FLat sections where my Mazda gets 50 mpg the Tahoe is managing mid 30s. Whats notable is that the first 1/3 of the throttle is programmed to be super sensitive which makes it feel gutless from a stop but makes for great ecosensitivity once up to speed. Much easier to drive it like an egg is under the pedal. Its surprisingly seamless going from V8 to V4 because the engine is so quiet and the engine vibration is so minimal you have to concentrate to feel the difference. I think this technology will be a boon to even us 4 cylinder and 3 cylinder folks if the manufacturers follow through in the years to come