Manual vs automatic

rtho782

A traditional auto box includes a torque converter. This is an amazing device, but some power is lost on it, this is what causes autos to have "lower MPG".

You then get CVTs, Continuously Variable Transmissions, they don't have such losses and in theory can be very efficient - they precisely match the gear ratio to engine characteristics - but they tend to be unreliable, especially with high torque engines (diesels.

The modern DSGs and equivalents, are not really autos, they are double clutch, computer controlled manuals. They are no less efficient than manuals, and will get the same MPG. They are more expensive to fix if they break as they are more complex.

Gloomendoom

If the driver doesn't need to select the appropriate gear or operate a clutch, it's an automatic.

If the driver has to select the appropriate gear but doesn't need to operate a clutch, it's a semi-automatic.

If the driver has to select the appropriate gear and operate a clutch, it's a manual.

almillar

Mmm, yeah. The DSG systems and similar are what I would almost call semi-automatic - there's no clutch pedal, but there is (at least) one clutch, and real life gears to change between. With us being lazy, they all, or almost all, have a 'D' mode, where the computer does all the work, but there really are gears.
Anyway, if you pass the test in anything without a clutch pedal, it counts as automatic.
Anyway, manual still has advantages, and auto, especially with DSG etc, has diminished the disadvantages. Autos were/are slower and less economical than manual, whereas these days, fast cars with good autos/DSGs are MORE economical and FASTER than a human with a manual can manage.
My wife's car is fast with DSG and stop/start and it's great, mostly, with frustrations that don't exist in a manual. Stop/start activates when you stop, with your foot on the brake pedal. If you DON'T want it to activate (you know you'll be moving again very soon), you have to be very gentle on the pedal. There's no clutch to help control stop/start). If you want to accelerate suddenly, it takes a while to find a gear - I can do this better in my manual. Moving from 'N' to 'D' requires you to put your foot on the brake - hugely annoying at traffic lights. Driving a fast car in manual gives more driver satisfaction than an auto. Blipping downchages, heel and toe etc can't be replicated, and I'm sure you have more control in snow etc in a manual.
Then I get stuck in traffic and a manual feels like so much work!
Let's not call either better, it's personal preference, but a lot of the disadvantages of autos have gone away in SOME cars.

Robisere

Spinal and other injuries caused me to lose much of the use of my left leg and I receved my first Motability car in 1995. (for which I will never forget to be grateful) I have never had a car with a manual 'box since and I would never go back to using a manual 'box, should a miracle give me back full mobility again.

Driving is so much more relaxed and there is much more time to think about driving conditions, other traffic and all the situations that occur on today's crowded roads. My current car is the second of two Ford C-Max 2.0 TDci auto's and I love it. I will pay a deposit and take another of the newer models next May. I may be 71, but I have driven many kinds of vehicles, from tracked APC's and trucks in the Army, to road tests of Classics like Astons and Jaguars, when I was a workshop foreman. I have driven a Ford Capri RS 3.1 around the Nurbugring in Germany. All of these were either work or fun, some were both, but I really enjoy my driving now.

I get a minimum of 45 mpg out of the C-Max and I am not one of those older, slower drivers that are often complained about here, but always use Cruise Control/speed limiter to drive within the limits. This adds to the relaxed driving factor.

I know the time will come when my reflexes will no longer be good enough to continue driving. When that happens I will hand over the keys and my licence, but for now I am grateful that I can drive in safety and comfort. And I will never drive anything with a manual 'box again.

Joe_Horner

reeac wrote: »

My recollections must come from the Owners Manual and we owned the car in around the early 1980s so I might be rusty but Wiki agrees with me that it was engine speed, not road speed that counted and clearly the front pulleys were connected to the engine rather than the rear wheels. Wiki also mentions the stresses and breakages caused by the lack of a true differential and, as I said earlier, we had two broken drive belts .... both times after turning a sharp corner. Interestingly, the car drove very smoothly with just one drive belt. As a plus point, I did once climb up a very icey driveway thanks to the limited slip effect.

My recollections come from owning 3 (two aircooled and a 66 Marathon Coupe) and rebuilding the vario units on two of those, including the only model 32 on Uk roads at the time (which had been dry-ish stored for something like 35 years before we got it and recommissioned it).

If you think about it logically, engine speed simply can't be the governor of the change-up because the whole point is that engine speed rises to, and remains constant @, maximum torque revs when the throtle's opened. The car then accelerates by changing up the ratio as road speed increases until it "catches up" with what the engine's doing. That's what creates the "slipping clutch" driving effect that so many people find unnatural about them.

Increased engine speed will try to change up but the change itself is governed by road speed (again, ignoring the vacuum system which can work in either direction).

Belts breaking wasn't to do with the lack of diff - it was due to wear / lack of maintenance (people never remembered to re-tension the belts as they were supposed to) / age (like any rubber item, they perish).

Looked after properly a set of belts was good for around 40-50k miles (so not much less than some cam belts) and could be changed on your drive in about an hour, or even by the side of the road if needed. Or you could just drive home on one!

Drive shafts breaking did happen but only at road speeds where both pulley sets were in low ratio (as mentioned, below about 10mph). As soon as they started to change up they became independent and could slow / speed up the rear wheels as needed.