Automatic vs Manual Transmission: How They Work and How to Choose

How a manual transmission works

In a manual transmission, the driver presses a clutch pedal to temporarily disconnect the engine from the transmission, moves a shifter to select a gear, and then releases the pedal to reconnect power. According to Wikipedia's entry on automatic transmissions, this design lines up gears along input, output and intermediate shafts, which is mechanically different from the planetary gearsets used inside most automatics.

How a traditional automatic transmission works

A conventional automatic replaces the manual's friction clutch with a torque converter, a fluid coupling that connects the engine to the transmission and multiplies torque at low speeds. Inside the gearbox, planetary gearsets produce the different gear ratios. Pressurized automatic transmission fluid, directed by a pump, engages friction bands and clutch packs to change ratio, and in modern vehicles solenoids controlled by an electronic transmission control unit manage the shifts, per Wikipedia.

• 1904: the Sturtevant transmission is considered the first automatic design
• 1940: General Motors' Hydra-Matic becomes the first mass-produced automatic
• 1948: Buick's Dynaflow introduces the torque-converter design now common in automatics
• 1989: Nissan's Jatco 5R01 becomes the first five-speed automatic
• Today: many automatics have 8 to 10 speeds with electronic control

CVTs and dual-clutch gearboxes: automatic, but different

Not every 'automatic' uses a torque converter. A continuously variable transmission (CVT) has no fixed gears at all — it uses two variable-diameter pulleys linked by a belt or chain, giving an effectively infinite range of ratios so the engine can stay in an efficient speed range, Wikipedia notes.

A dual-clutch transmission (DCT) is closer to a manual gearbox that shifts itself: it uses one clutch for odd-numbered gears and a second for even-numbered gears, according to CarsGuide. While one gear is engaged, the next is already pre-selected on the other clutch, which allows near-instant changes and makes DCTs more efficient and responsive than torque-converter automatics, CarsGuide reports, while still letting many drivers shift manually using paddles.

CarsGuide also points out that early dual-clutch units could feel jerky or hesitate at low speed if poorly calibrated, citing Ford's 2011–2018 Powershift DCT as an example that led to reliability complaints and legal action. A related design, the automated manual transmission (AMT), simply automates the clutch and gear selection of an otherwise conventional manual gearbox, per Wikipedia.

Manual vs automatic: cost, upkeep and driving feel

How to choose when buying a car

1. Think about where you drive most: heavy stop-and-go traffic favors the ease of an automatic or CVT, while open-road or performance driving may suit a manual or dual-clutch gearbox, per DRiV Parts.
2. Compare the purchase price and typical resale value for the exact model and trim — manual versions are usually listed cheaper, while automatics tend to hold value better, DRiV Parts notes.
3. Ask about service history and likely upkeep: manual gearboxes are generally less costly to maintain, but automatics bring their own repair costs if the transmission needs work.
4. Consider who else will drive the car — automatics require no special coordination and suit multiple or less experienced drivers, while a manual demands clutch skill, per DRiV Parts.
5. Check exactly which transmission type the trim uses: 'automatic' today can mean a torque-converter unit, a CVT, or a dual-clutch gearbox, and each shifts and feels differently, according to Wikipedia and CarsGuide.
6. If you specifically want a manual, confirm it is still offered on that model — manual take-up in the US fell below 1% of new-vehicle sales in model year 2021 and has stayed there since, so availability is limited, per The Autopian.
7. Where possible, test-drive both versions of the same model before deciding, since the feel of shifting is subjective and the figures above only tell part of the story.

Why manual transmissions are disappearing

Manual transmissions once dominated the US market: in 1980, just under 35% of new vehicles came with a stick shift, according to The Autopian's reporting on the EPA's Automotive Trends Report. That share fell below 1% in model year 2021 and has remained there since. For the 2024 model year, The Autopian counted only about 30 manual configurations across the entire US lineup — one five-speed, 27 six-speeds and two seven-speeds — citing the EPA data as more authoritative than a higher, partial-year 1.7% take-rate figure reported separately by J.D. Power for 2023.