4 ms·
They do, they just unlock the torque converter or downshift as you accelerate. They shift to top gear before the equivalent manual does, and you'll find automat
by coryrc 3y ago
They do, they just unlock the torque converter or downshift as you accelerate. They shift to top gear before the equivalent manual does, and you'll find automatics have significantly lower gear ratios than the manual transmission of the same vehicle. This is the only reason their gas mileage is close to manual transmissions, because manual is ~97% efficient while automatics are 85-90% -- planetary has 3x the mating surfaces plus there are three (or more) sets of them. Typically third gear is straight through and what you get when you disengage OD, which is half the reason you use it when towing.
- jerlam 3y agoWhile manuals may be more efficient, most cars with automatic transmissions now have the same or even slightly better estimated gas mileage than cars with manual transmissions, assuming you can even find the latter.
- coryrc 3y agoYes, because the lower gear ratio of the automatic allows the gasoline engine to operate in a more efficient portion of the bsfc curve, which makes up for the substantially higher transmission losses.