Im just wondering what it is that makes automatic cars slower than manual cars ? I know that now with some of the new double clutch boxes ( dsg etc ) that this isn't the case but I'm talking about just the standard type auto boxes. is it because the gear changes are slower but acceleration in between gears is the same or does the auto box use up power from the engine reducing the overall power ?

I am looking for a BMW at the moment and have notices its quite a significant difference in 0-60 times for example 325i Manual - 6.9 and 325i auto is 7.6. Thats almost a full second slower to 60 and the 325i manual almost does the same 0-60 as the 330i auto think there is 0.2 seconds difference ! Range Rover Vogue 2006 4.4 AJV8 | Buckingham Blue | Parchment Leather | Supercharged Grill+Side Vents | CA02 HEY ( NOT 02 PLATE )

i think the autos change gear at lower revs than a manual which can be taken up the the red line..



and tbh loosing a second or two on acceleration wont make any difference in real world driving... ... - .- -.




Y. O. L. O.
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It's mostly torque convertor slip that saps power, in an auto the wheels aren't directly connected to the engine, the TC has to slip to get it moving, in a manual, once the clutch is fully engaged all the power goes to the wheels...

If you want traffic light grand prix starts then an auto will usually win, you will get a much faster getaway than someone who has to get the clutch balance sorted and not spin out the wheels or bog off the line...

Plus.... why have a manual, the manufacturers spend a fortune to make our lives easier now with all sorts of automatic gizmoes so we don't have to move a finger, then they put 6,7 or 8 speed gearboxes in so you spend all your time changing gear, drive through London during rush hour and you feel like you've been down the gym.... Pete
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All that handraulic stick waggling to save a few tenths off the line. Once the torque converter has locked up the auto is quicker anyway, smoother and faster gear changes with no left leg & arm shenanigans.

Power loss through the gearbox, auto's are better than they used to be with electronic operation, older auto's used hydraulic pressure to make the changes, thus sapping power.

I have a manual 2.5 v6 car, 0-60 in 8 secounds but my Td6 feels quicker on the acceleration.

Haylands has a nice answer. Also, autos are more complicated and often heavier than manuals, which will also make a difference.

Before the FFRR I was definitely a manual fan. In a 4-cylinder car, 3 sp auto or 5 sp manual? Manual every time!
Nice, sophisticated automatic in a V8 petrol? Rather a different story.

As stated its the losses in the Torque converter, sometimes couples with the gearing itself. Autos tend to have less gears, so will not always have the best ratio for power, meaning slower acceleration.

These days with autos having more gears, multi-plate clutches and the like rather than an old fashioned Torque converter it can be a very different story. My Father in Laws TSi golf had 7 or 8 gears, and seemd to be adept at keeping itself constantly in its power band, meaning it was devastatingly quick and responsive the entire time.

MW

Also generally the equivalent auto would have fewer gears so would have to go faster in each gear and drop the revs more on changes. So you have a combibation of higher general losses, fewer gears, torque converter slippage and possibly more weight.

MC