Jump to content

Latest Generation Automatics..


Recommended Posts

Just why are the latest generation of auto transmissions so much better than they used to be? In what way have they improved so drastically?

Since passing my test over 20 years ago ive always treated autos as the spawn of satan himself. Hated them. They drank fuel. There performance was carp. Both mainly due to the fact that they seemed to be losing drive with what sounded like a slipping clutch. Oh and they seemed to have a mind of there own changing upand down as they saw fit. The last one i drove sang soprano when going up a slight hill trying to keep a steady throttle.. Just trying to keep a steady 30mph the gears went 2,3,3,2,2,3...... Lol

Now however they seem to be the thing to have. Especially as traffic jams are more and more common.

Checking out the specs of the new discovery sport show that you can have a 6-speed manual or 9-speed (yes 9 speed) auto. You just know that thing will be awesome. In fact the 0-60 time is 1.5 seconds quicker than the manual!

Link to post
Share on other sites

The old ones were mechanical devices, the new ones are electronic which uses various sensors and can be programmed to respond a lot more effectively. They can also be reprogrammed by the driver depending on how they want to drive.

I don't know the mechanics of them but when you drive them they often feel like a manual changing gear as if it's a manual box with actuators on it.

Certainly the 12 speed automatic lorry I drove felt like that, you could hear pneumatic actuators working and it lost drive between gears. It would also account for the improvement in economy due to the higher number of gears and fewer mechanical losses.

Link to post
Share on other sites

I think some of the lorry auto box's are automated manuals; they still have a clutch but it is actuated electronically rather than by the driver.

I had a Peugeot Bipper with a pileof****e 2-tronic gearbox, basically a manual with electronic control, after 3 years with it, I can honestly say it was carp to the point of being dangerous.

I'm far from an expert on auto's but my basic understanding is auto's are epicycle so one gear pack gives you in effect 3 gears, depending on whether the sun wheel, planet wheel or annulus are locked, so I'm assuming an extra gear pack won't give you an extra 3 gears but could give you an extra 6 gears or something along those lines, a gross over simplification granted but hopefully you get the idea.

Probably the biggest difference in electronically controlled auto's is the ability to lock up the torque convertor,To get better economy you want the engine driving at its most efficient RPM, with a electronically controlled auto you can remove driver error, for maximum acceleration you want the engine at peak torque, so with a modern auto its programmed to keep the engine at peek torque under hard acceleration and with a choice of 6,8 or 9 gears and a TC that can be locked at will, it has a fair selection of tools to choose from.

The best gearbox for acceleration would be one that kept the engine at peak torque constantly and continually varied the stepless gearing, a 9 speed auto with a clever TC is going to start getting pretty close to this I would of thought.

Mechanical and pumping losses, like everything else I suppose, have been reduced by more efficient systems in the same way as engines have.

I drove manuals exclusively for 20 years and had much the same opinion as the OP, for the last 10 years its been auto's and despite the Bipper I would not buy another manual.

Link to post
Share on other sites

My 9 speed auto evoque was poorer in terms of the driving experience than my 8sp D4. The D4 had oodles more torque available than the evoque so I presume was partly the reason why it was suited better to the auto. The D4 would always appear to be in the proper gear where as the evoque always had a little time to think which gear it would like.

In traffic they were a god send, even knocking the D4 into low when crawling along was a doddle. You certainly feel it in the calf muscles when using the defender in queues!!

Link to post
Share on other sites

I agree about the clutch leg on the lorries and I love the auto for offroad as you can go as slow as you like with left foot braking but for normal driving it has to be a manual. Even in the lorries I find your trying to second guess the gearbox all the time rather than just putting it in the gear you want.

Link to post
Share on other sites

Modern intelligent slushboxes are indeed a spectacular advance on the clockwork/hydraulic offerings of the last millennium. In the general sense.

In part they're a response to modern turbodiesel engines with rather narrow optimum torque/efficiency-bands [hence the loads-of-ratios].

Alas most of them these days come with a default shift-map optimised for economy/emissions and 'grandad'-style driving rather than performance. My hate is - when driving on a twisty road at 50/80MPH - you lift-off the throttle and the slushbox shifts from 5th to 8th so you find yourself half way round an interesting double-bend with the engine doing 1100RPM and the turbo doing nothing, just when you really need to be on the torque-peak !

OK, you can stab like a maniac at the downshift-paddle on the steering wheel but even so it usually expects you to go stepwise 7-6-5-4 before finally arriving at 3 and so letting the engine start to dceliver the goods. And I'd rather not have to be doing that part way round a bend.

Some modern slushboxes claim to have "fuzzy logic" and learn your driving-style. I've not found one that does this properly (I would love a "change down unless to do so will redline the engine" shift-profile).

Link to post
Share on other sites

I too spent 10 years punching 'eighties artics, mostly with multi speed Fullers, up & down the UK. When it comes to auto's, of which I've owned several, a 2 speed (yes you read it right) powerglide coupled to a torquey 3.3 straight six always seemed enough. Why anyone needs so many ratios in today's autos is beyond me, especially when it goes wrong!

Link to post
Share on other sites

Most of the appeal of an auto is that you have to have a decent engine on the front of it and if you compare a D4 SDV6 with 255hp to a D2 Td5 with about half the power and torque it's not surprising they are much better pushing an auto. The new engines can rev without sounding like a freshly branded heifer too, which helps.

I've driven a current model year D4 (my father has one) and it is very competent but even the V6 with more torque than a locomotive still doesn't manage the wafting sensation that my ancient V8 has - I drove the D4 when it was brand new and it might have been in some sort of running in mode but I thought the throttle response was odd, there was nothing and then there was everything in a hurry. Went like excrement off a digging implement when you planted it. All the individual bits of the modern zillion-speed diesel autos are very capable but even in the D4 the whole symphony still doesn't quite come together in the same way in my opinion. It is ten times better than the Td5 auto or anything else from that generation with a diesel engine, but I still don't know what I am going to buy to replace the D2....

Link to post
Share on other sites

This is kind of turning into a "which is better" kind of thread now.

In that case...... Like i said in my op, i used to hate autos so much. And if most of my driving was in the open countryside with hardly any traffic, i probably still would. The thing is i live like most people in a built up area, and a lot of my driving is stop-start. Sometimes in the case of the motorway its just stop-stop. In this case i would now say id be tempted more towards a modern auto.

I never thought id say that, but driving conditions and the vast improvement in auto transmissions has swayed me.

I will always have a big manual v8 as a toy, but for everyday rush hour traffic? Thats a different story these days.....

Link to post
Share on other sites

Indeed... I have an audi coupe, manual, and my RRC auto, I prefer to drive the RRC round town every time(!)

The need for many-speed autos has arisen as modern diesels still only have a pretty narrow power band, compared to petrols, and with diesels being more and more popular (more diesels are sold new than petrols nowadays) they had to come up with something better for the diesel crowd.

Still think CVT boxes, once reliability can be guaranteed, are the way to go.... even if they make the engine sound odd as you accelerate :)

Then again, the double-clutch gearboxes are another option... :)

Link to post
Share on other sites

the multispeed autos are needed just as multispeeds for truck diesels , due to very limited rev range where they are efficient developing the peak torque . the locking converter has been the big savior of the auto , as without they loose fuel gains , but even now they are very variable even with the scg boxes used in HGVs . Some autos of same make/design can vary depending on vehicle fitted in , getting it just right seems still to be more by luck than judgement JMHE

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy