The word "upshift" is correct and usable in written English.
It is typically used in contexts related to increasing speed, intensity, or level, often in discussions about performance or progress. Example: "The team decided to upshift their efforts in order to meet the project deadline." Alternatives include "accelerate" or "increase intensity."
With the transmission in automatic D mode, this is accompanied by a downshift, plenty of engine revs and some dramatically sputtering sound effects with each subsequent upshift, but if you're in manual mode, with steering-column paddles to control the gears, you can stay in a high gear and still the M5 erupts into ballistic thrust.
Manual shifts are via the central lever: back for an upshift, forward for down, the reverse of the usual movements but actually more natural.
There's virtually no pause when you punch the pedal, and under hard acceleration the transmission will hold a gear until the engine speed nears the red line, prompting an upshift.
Hustling up a rocky embankment here at the testing grounds of the Quadski's maker, I cranked the handlebars left, downshifted to first gear and cautiously fed some gas with my right thumb while repeatedly poking the upshift button with my left.
What the new paper by Hastings and Shapiro does is to show that the same kind of behavior continues to apply, with consumers shifting to lower-grade gasoline when gas prices rise, to higher-grade when they fall; the upshift happens even if incomes are falling.
Making an upshift with the paddles behind the steering wheel feels like directing a choir to drop an octave.
Though eighth gear does give a very restful and relatively frugal cruise, having eight gears is too many for an engine with such a broad spread of huge pulling ability, so I tended to use the paddleshift manual mode on twisting roads to stop the endless upshifting and downshifting that is especially irksome in the Sport mode.
There is no human telemetry to decode the primal upshifts that make the Hamiltons of this world that bit faster in a racing car.
The vehicle speeds at which shifts occur depend on the position of the accelerator pedal, and the driver can delay upshifts until higher speed is attained by depressing the accelerator pedal further.
Each type provides for manual selection of reverse and low ranges that either prevent automatic upshifts or employ lower gear ratios than are used in normal driving.
I never completely got the hang of the 3-speed transmission, and crunch-free upshifts were rare.
