Are Automatics slower than manuals in gear?

[V8Wagon]

I appreciate that Auto's are generally a tad slower accelerating than manuals. Do they lose the pace during the shifts?

My auto is tiptronic so can be held in a gear......if raced against an identical manual car in the same gear, without changing gear over a short distance would the auto still be slower?

[freecar]

Autos generally have different ratios to the manual counterparts.

Usually the Auto has less gears and therefore longer ratios, so if the Manual were stuck in 2nd and the Auto the same I'd expect the auto to have the higher terminal speed.

[maniac0796]

If you look at the difference between the gear ratios for a manual and a automatic on the same car, you'll see the automatic has much longer ratios.

[anonymous-user]

Most of the advantage of a modern manual transmission over a modern autotransmission is in the lauch. On a manual car, you can use the engines mechanical inertia to help get the inital tyre slip required to nail a perfect launch. On auto trans, generally the engine revs and maximum throttle position are in fact limited at zero vehicle speed.

Auto's actually outperform the conventional manual transmission during shift events becuase they are able to keep on positive torque throughout the shift, whereas a manual must drop torque close to zero to get the dogs unlocked


Historically, as mentioned the fewer availible ratio's in a typical old style transmission did of course mean that the engine was not kept as close to peak power as with a manual with more gears.


Modern auto's with 8 spds, wet multiplate clutches (rather than a torque convertor) and accurate shift control that can exchange ratios under virtually full torque, almost match a manual transmission, and would outperform one if the transmission calibration were completely otimised for performance rather than durability.

[GroundEffect]

By identical, do you mean the same ratio? If so, the manual car would only be faster by the power of it's lower transmission weight (torque converters aren't light).