[inferiorhuman]

> Driving a manual car isn't about efficiency.

It was about efficiency and cost for ages though. That's why manuals were popular and why they aren't popular in the US anymore. Modern automatics (dual clutch, CVTs, even computer controlled single clutch and plain old torque converter slushboxes) are so much more efficient now that manuals don't make as much sense as they used to.

[kaitai]

Agree, simply in that by changing my driving style I could get 30+ miles per gallon of gas using a manual but not an automatic of the same type of car. It's interesting that people don't even know that anymore. Additionally, manual can be very useful in a snowy/icy climate -- starting into 2nd can get you going on a slippery road where some automatics will have trouble. Much more control of torque.

[argonaut]

For new cars today, though, automatics are almost always more fuel efficient.

[kalleboo]

Mechanically more fuel efficient, absolutely.

But when I still drove a manual it always felt like I was planning ahead, engine braking early at red lights (which often meant I could coast though it without completely stopping) etc, which you can't do with the lesser control on an automatic. Driving "lazily" in a manual means reducing shifting which often translates to more fuel-efficient driving. Driving lazily in an automatic is very different.

I'd love to see a study on hypermiling with auto vs manual in real-world condition. AFAIK all the efficiency numbers we have are just based on purely mechanical tests on a driving cycle on a dynamometer, and we all know what that kind of testing leads to.

[inferiorhuman]

> But when I still drove a manual it always felt like I was planning ahead, engine braking early at red lights (which often meant I could coast though it without completely stopping) etc, which you can't do with the lesser control on an automatic.

Sure you can.

[hfdgiutdryg]

A modern DCT transmission doesn't use a torque converter, which is where most of the efficiency was lost. A DCT is effectively a manual transmission that's automatically operated.

[davewritescode]

Even torque converter automatics don't use torque converters for anything other than low speeds anymore. Most modern automatic transmissions have the ability to mechanically couple the input shaft directly to the transmission effectively bypassing the torque converter in most if not every gear.

It's one the of the reasons the ZF8 transmission is used in everything from the new BMW 8 series down to the Dodge Charger.

[hfdgiutdryg]

Even torque converter automatics don't use torque converters for anything other than low speeds anymore.

Unless something has changed radically in the last few years, that's just not true. The torque converter will drop out of lock-up as soon as you demand sufficient acceleration (this will vary tremendously by engine - i.e. an inline four will do it regularly, a big V8 may meet most of your acceleration needs without dropping out of lockup) or tap the brakes. Torque converter with lockup have been around since 1950ish.

[davewritescode]

Locking out the torque converter isn't a new idea, it's just that newer transmissions are very aggressive with engaging the lockout thanks to all the software that lives in a modern car.

Having spent a decent amount of time with ZF8 speed the torque converter is almost always locked out. Throttle response and engine braking don't lie.

[hfdgiutdryg]

I don't understand what throttle response has to do with demonstrating that it's in lockup. With an average car engine, you're going to get fairly disappointing acceleration with the torque converter locked up. I suspect that what you're seeing is the effect of having a torquey, high performance engine, based on the example cars you listed. They just don't need to drop out of lockup to deliver the day-to-day acceleration you want. Also, performance car transmissions have been tuned to behave differently than run of the mill transmissions for at least as long as I've been driving. For example, engine braking in my college friend's then-new 90s Mustang GT, whereas my family sedan would prefer to free-wheel.

Edit: by the way, I looked up the ZF8 and it's available in a bunch of configurations. One of them is a wet clutch instead of a torque converter, which I imagine has to operate like an electronically controlled manual transmission. There's even an option to have an electric motor instead of a torque converter for hybridization!

[Krasnol]

This is the first time ever I hear about efficiency in this context.