prefer tags all day long, better turning, better traction. less repairs ie ball joints track bars,king pins etc, tags are better plus as said better range of fuel as well for the gypsies to steal on a night out 
A tag axle 6x2 is, in most cases, more heavy duty than a simple mid lift, with the wheels down traction will be the same as a mid lift with all wheels on the ground, lift either and you increase traction, the tag will, depending on the 5th wheel position, create a pendulum effect taking weight off the front axle too, so you can get better traction in some cases, but then you lose traction on the steering axle so going around corners isâŠinteresting 
Itâs the same with the wheels down on a tag, understeer is more of an issue than even a non steering mid lift, even more so on short wheelbase units, the older mechanical sprung/hydraulic lift versions were far more prone to this than the newer air suspended versions.
The main thing with a tag is 5th wheel positioning, if itâs behind the center line of the drive axle, youâll get a see saw effect when you lift it, going down the road this can make it feel a bit âfloatyâ a decent driver will compensate in his driving style, but any idiot can drive a mid lift 
TONY530I:
Harry Monk:
We used to have tag axles but eu turning circle legislation made it difficult for them to comply with the law.Can you explain what your talking about?
Ă© The Transport Managerâs and Operatorâs Handbook
By David Lowe
A tag configuration has a short wheelbase between steer & drive axles & can therefor turn tightly. I know, I owned one. I remember well the uncomfortable ride (on steel) when bob tailing.
So I too am confused by Harryâs statement.
Driveroneuk:
A tag configuration has a short wheelbase between steer & drive axles & can therefor turn tightly. I know, I owned one. I remember well the uncomfortable ride (on steel) when bob tailing.
So I too am confused by Harryâs statement.
I think the problem with tag axles was the axles ripping the cladding or cross members off trailers when they were raised if the driver was not aware
6x2 stralis often seem to come with a steering mid lift.
Driveroneuk:
A tag configuration has a short wheelbase between steer & drive axles & can therefor turn tightly. I know, I owned one. I remember well the uncomfortable ride (on steel) when bob tailing.
So I too am confused by Harryâs statement.
Thatâs what my boss told me and heâs owned a few in his time. Perhaps there is another reason for their decline, I donât know.
Just a quick update, I phoned my (ex) boss and he said âWell, isnât it obvious that if the drive axle is forward of the pin rather than behind it, that the truck will need more room to turn?â
I felt a bit of an idiot for asking, but as I said to him, I was only passing on questions.
Basically, eu turning circle legislation is what killed off tag-axle tractor units.
As I said in the first place 
hmm, after few vino rouge Iâll have to give that one some further thought. 
Harry Monk:
Just a quick update, I phoned my (ex) boss and he said âWell, isnât it obvious that if the drive axle is forward of the pin rather than behind it, that the truck will need more room to turn?âI felt a bit of an idiot for asking, but as I said to him, I was only passing on questions.
Basically, eu turning circle legislation is what killed off tag-axle tractor units.
As I said in the first place
Is that with the tag up or down
Harry Monk:
Just a quick update, I phoned my (ex) boss and he said âWell, isnât it obvious that if the drive axle is forward of the pin rather than behind it, that the truck will need more room to turn?âI felt a bit of an idiot for asking, but as I said to him, I was only passing on questions.
Basically, eu turning circle legislation is what killed off tag-axle tractor units.
As I said in the first place
Blimey itâs picking on Harry week for me
I think your man is wrong H? A tag usually has a 3.1m or 3.4m wheelbase, whereas a midlift has a 3.8m or 4.1m wheelbase, in this case wheelbase is measured from the center of the front axle to the center of the drive axle, so even though your 5th wheel is behind the drive axle it will be the same approximate distance from the center of the front axle in both configurations, or it should be if the pin setting on the trailer is correct and you donât have to have the 5th wheel back to avoid fouling the underside of the trailer or hitting the legs/ripping the lights off
Iâm trying to work it out in my head, but itâs all a bit fuzzy, Iâm thinking that if the 5th wheel is behind the drive axle it should turn tighter, as you turn the unit the overhang effectively pulls the trailer out in a wider arc in much the same way as the overhang on an A frame wagon and drag does, those turn real tight with hardly any cut in, even in Crazyfastâs favourite rigid/13.6m trailer guise, I havenât had a tag since the late 80s so itâs been a while, but I canât remember any noticeable difference, except that it rode like it had solid tyres and didnât like going around corners, yep, it was a Scania 
Beef:
Why is this
Answer to this is simple, there are different needs for different types of operations Also, there are different type of needs when same type of operations are executed on different regions (hint: think about Norway and UK for example).
Beef:
And what are the pros and cons of these different configurations
Most noticeable pros and cons have already by other members, but hereâs some sort of a list about main differences. When axles are down there arenât that much of a difference between them to. Amount of trailer âpeepingâ behind the cab when turning can also be different. I donât know enough about economical viewpoint to comment it but there likely are some differences.
Midlift - pros:
- Longer wheelbase when running light - smoother ride
- Lifting axle up transfers weight to the front axle - not so likely to under-steer
- Destroying your rear lights to trailer chassis when turning with axle up not likely (if even impossible?)
Midlift - cons:
- Longer wheelbase makes it awkward compared to tag axle unit.
- Lifting axle up doesnât give so much extra weight for drive axle - youâre more likely to get stuck on slippery surface
Tag - pros:
- Shorter wheelbase - easier to maneuver on tight places
- Lifting axle up transfers weight to drive axle, even when pin is in front of drive axle, hence giving superb traction compared to midlift
Tag - cons:
- Itâs possible to destroy your rear lights to trailer chassis when turning and tag is up - you need to look out for it when maneuvering.
- Lifting axle up reduces weight on front wheels exaggerating the under-steer effect.
- When driving tag axle up ride will feel a bit wobbly compared to midlift and it might take some time to get used to it.
Harry Monk:
Just a quick update, I phoned my (ex) boss and he said âWell, isnât it obvious that if the drive axle is forward of the pin rather than behind it, that the truck will need more room to turn?â
That only holds true if wheelbase from front axle to drive axle stays the same. If you take midlift and tag axle outfits with same distance from front axle to third axle, then also second axle is likely on the same spot on both outfits. If also fifth wheel is on the same place then tag axle artic will need less space if units front wheels travel same tracks as the unit of midlift outfit. This happens due to tag axle units shorter wheelbase and from rear overhang of the fifth wheel.
Edit: And newmercman beat me while I was having a brew. I shouldâve wrote this reply to Harry immediately
I may have beat you Kyrbo, but your post looks more professional with quotes and bullet points
Well, you see I donât actually know anything at all and just rely on advice given by people who do
But this would seem logical, given that the turning circle legislation was implemented in 1998 (as I understand it) and this was when tax axles seemed to disappear.
And yes, I too have had the experience of bobtailing in a steel-sprung Scania!
Harry Monk:
Well, you see I donât actually know anything at all and just rely on advice given by people who doBut this would seem logical, given that the turning circle legislation was implemented in 1998 (as I understand it) and this was when tax axles seemed to disappear.
And yes, I too have had the experience of bobtailing in a steel-sprung Scania!
I think the turning circle legislation came about when we got longer trailers, it was all brought about by the French and the Dutch and their desire to cram as much into a lorry as possible (do you remember the DeRooy and Nobrot Dangerousangle units where the driver was almost standing up?) so the EEC in itâs wisdom granted us 16.5m overall length, but maximum trailer length of 13.6m, that way we could still drive lorries if we were taller than Gogzy anyway to appease the tree hugging fraternity they said these juggernauts had to be able to turn in a circle as in Wheelnutâs post, thatâs why the front corners of a 45â box are chamfered in, otherwise they wont go round in that aforementioned circle.
Now back to tag axles, when the 38tonne limit was introduced in the UK, our exsisting trailer parc was almost 100% tandems, so we needed 6 wheeler units, manufacturers just used designs that they already had in their range, the Swedes went for tags, the Germans/Dutch/Italians went for twin steers, the Brits went to Primose etc and just nailed axles on 
It took a few years before things settled down and it was found that the midlift was the best choice for regular 38/41/44tonnes in the UK, so the tag all but disappeared
newmercman:
it was all brought about by the French and the Dutch and their desire to cram as much into a lorry as possible (do you remember the DeRooy and Nobrot Dangerousangle units where the driver was almost standing up?) so the EEC in itâs wisdom granted us 16.5m overall length, but maximum trailer length of 13.6m, that way we could still drive lorries if we were taller than Gogzy
You forget that Bowker and Yeardley were also big users of Eurotrotters with a plywood bulkhead and no room for a â â â â bottle behind the seats.
newmercman:
Harry Monk:
Well, you see I donât actually know anything at all and just rely on advice given by people who doBut this would seem logical, given that the turning circle legislation was implemented in 1998 (as I understand it) and this was when tax axles seemed to disappear.
And yes, I too have had the experience of bobtailing in a steel-sprung Scania!
I think the turning circle legislation came about when we got longer trailers, it was all brought about by the French and the Dutch and their desire to cram as much into a lorry as possible (do you remember the DeRooy and Nobrot Dangerousangle units where the driver was almost standing up?) so the EEC in itâs wisdom granted us 16.5m overall length, but maximum trailer length of 13.6m, that way we could still drive lorries if we were taller than Gogzy
Now back to tag axles, when the 38tonne limit was introduced in the UK, our exsisting trailer parc was almost 100% tandems, so we needed 6 wheeler units, manufacturers just used designs that they already had in their range, the Swedes went for tags, the Germans/Dutch/Italians went for twin steers, the Brits went to Primose etc and just nailed axles on
But there was another way (6x4) before we let the lunatics take over the asylum. 
Tin hat on.
Wheel Nut:
newmercman:
it was all brought about by the French and the Dutch and their desire to cram as much into a lorry as possible (do you remember the DeRooy and Nobrot Dangerousangle units where the driver was almost standing up?) so the EEC in itâs wisdom granted us 16.5m overall length, but maximum trailer length of 13.6m, that way we could still drive lorries if we were taller than GogzyYou forget that Bowker and Yeardley were also big users of Eurotrotters with a plywood bulkhead and no room for a â â â â bottle behind the seats.
Didnât want to steal your thunder MalcâŠHonest
The common denominator here is Phillips I once saw a DeRooy outfit, a 2500 Daf wagon and drag chassis, but it had a one piece body that IIRC was over 50â long, the body was mounted on two 5th wheels, the one on the prime mover fixed, the one on the trailer a sliding affair, that thing had 20â bits of chassis poking out when it turned and it also had the back of the cab shaved and a piece of ply as a rear wall that started at the back of the doors, with the big old flat steering wheel in those Dafs I would not even be able to get in the cab 
newmercman:
Now back to tag axles, when the 38tonne limit was introduced in the UK, our exsisting trailer parc was almost 100% tandems, so we needed 6 wheeler units, manufacturers just used designs that they already had in their range, the Swedes went for tags, the Germans/Dutch/Italians went for twin steers, the Brits went to Primose etc and just nailed axles on
Always remained popular up Aberdeen way, and now that Daf and Man offer this layout it has been making a bit of a comeback in recent years. Also spotted an Actros mega space Tag axle in Martin Benjamins thread in the picture forum. D Steven of Wicks R620s seem to be all Tags, thought this might have been to do with chassis space so they could carry the same fuel and fit on the ad-blue tank.
Carryfast:
But there was another way (6x4) before we let the lunatics take over the asylum.
Yep, 6x4s are very common in South Africa but they are allowed more weight there (MGW is 53 tonnes iirc), the roads are sometimes poor and fuel is cheaper. The disadvantages of 6x4 are the increased tare weight and that they use more fuel due to friction loss, for no real benefit at the weights we run.