As far as i can tell wheels vs tracks were decisions were mostly about costs if not outright acquisition cost then ,lifespan costs

Of course, i can imagine theatres like sub-Saharan Africa where the French rely on mobility to self deploy for considerable distances wheeled makes sense, going far is hard on tracked vehicles ,although i would imagine with rubber tracks the wear and tear on tracked vehicles should be considerably lower than with metal tracks 

Mr. T (MrT4) said:

I have seen in our 8x8 off-road trials with old BRDM2 was used a benchmark against PATRIA AMV 8x8 , Pandur II 8x8 and Armored Hummwee , while low powered by modern standards its extremly off-road capable.

Apples and oranges.
You can not compare vehicles that are so different with very different capabilities in such an easy way.
Of course an armored Humwee is shitty cross country over soft ground. It has only four, rather small wheels and a high load per wheel.
The BRDM is comparable lightweight and with its auxiliary wheels lowered has a very low ground pressure. But its poor in every other regard. Even an armored Humvee is better protected.
The AMV and Pandur II have twice the weight of the BRDM. They are also not amphibious. So of course there will be situations where the lighter weight of the BRDM is an advantage. There is no free lunch. If you want protection you will have to accept weight. Its really that easy.
I would pick an AMV or a Pandur over an BRDM every time. They are generally far superiour vehicles.

BTW the cross country mobility of the BRDM is shit compared to some vehicles of the same(ish) era. The Luchs recon vehicles the German army used to opperate is much, much better. Its about as close to a tracked vehicle as you can get with wheels.
The 6x6 Fuchs also has awesome mobility in its original configuration. The up armored versions in use nowadays are still en par with more modern 8x8. Both are also amphibious.

In general the softer the ground gets the more you need tracks. The tiny Wiesel or the large Leopard will outperform any wheeled vehicle under such conditions.
The bester over all cross country vehicle I know is the Hägglund BV206. If it can't get there you need a helicopter.

Mr. T (MrT4) said:

have you seen the tires used ,they look like those used on dump trucks in qearies , because of the weight these are hard-wearing but not very mud capable , Russian tires are crap low mileage but very aggressive mud profile and rather soft sidewalls for central tire pressure regukation.

This is because western militaries in peace time (in general) use civillian street legal tyres. These are of a mixed road-cross country type. With a cross country ratio of 20-40 % (which is in deed what construction or forestry vehicles use). These tyres are for peacetime and training use. There are other tyres available should it be required.
The advantage is pretty obvious the tyres have a long lifetime and are reliable. The full cross country mud tyres have very poor on road performance and get used up very quickly on hard ground. Even gravel roads. It makes no sense to use these because there are a few days a years where there might be soft and deep mud somewhere. BTW in most of Western Europe there isn't.

graylion said:

But while COIN saw a surge of wheeled AFVs, is it maybe time to go back to more tracked vehicles?

This is allready happening.

graylion said:

Like Hungary buying Lynx.

That is not a return to wheeled vehicles.
The Lynx brought by Hungary is a IFV. So far no major nation has adopted wheeled IFVs. Its only wheeled APCs.
Befor someone asks: no the presence of an autocannon is not the difference between an APC and an IFV.

schnuersi said:

Befor someone asks: no the presence of an autocannon is not the difference between an APC and an IFV.

so, what is?

stancrist said:

The Marines seem to disagree.

We don't know if the Marines disagree. We know the decisionmakers do.

stancrist said:

They are planning/preparing for (near) peer conflict

True but as far as I know they are planing to fight in a very different way from how they did in the last decades.

stancrist said:

are getting rid of their tanks and going wheels all the way.

Because they are more focussed on strategical mobility. They need light vehicles for easy transportation. I also would ask: do they plan to conduct combined arms manoeuver warfare on soft ground? Deep snow?
In MOUT the lack of tracked vehicles really can bite them in their lower backside.

In general its not a good idea to argue on the base of what equipment was purchased. This is hardly every the best or what is really needed. It usually, in the vast majority of cases, its the cheapest. If one is lucky it also might be what some decisionmaker thinks that is needed. The conclusion: "they bought it, so it must be the best" can not be drawn.

Mr. T (MrT4) said:

Of course, i can imagine theatres like sub-Saharan Africa where the French rely on mobility to self deploy for considerable distances wheeled makes sense

Yes this is one environment in which wheeled AFV thrive. The ground usually is on the hard side, little mude (for lack of water) and the travel distances are huge.

Mr. T (MrT4) said:

although i would imagine with rubber tracks the wear and tear on tracked vehicles should be considerably lower than with metal tracks

Oh god no!
Its the other way round. Rubber tracks have horrible high wear. Under cetrain conditions its lower compared to metal tracks but these conditions are soft and ideally wet ground. Not dry and hard.
The problem with long range travel for tracked vehicles is not or not only the track itself. Its also the roadwheels, drive sprocket and suspension. The suspension and the hub and bearing of the roadwheels get hot when traveling long distances. So there have to be breaks for cooling down. The roadwheels have a rubber lining wich is at least as susceptible as the rubber track pads.
It should be noted that most tracked vehicles are simply not designed for long range travel. It certainly would be possible to optimise in this regard and improve the performance but so far nobody really saw the need.

graylion said:

so, what is?

The mission of the vehicles is different. Allmost entirely.

An IFV is a armored fighting vehicle that is supposed to work in close cooperation with tanks. Its supposed to be on the frontline and fight. It needs to go where tanks go.
An APC is a transporter that can deliver its passengers to a fight. Its not supposed to take part in it.

Its a doctrinal and tactics thing.
Simplified: an IFV is a light tank that carries some dismounts that can be deployed if the situation requires. The IFV is the main asset in this combination.
An APC is a transporter who carries the main asset to its area of operation. The focus of an IFV and an APC are direct oposits.

This is why wheeled APCs work and wheeled IFVs don't.

Was not suggesting a BRDM over any modern 8x8 , its just that it seems ever heavier 8x8 have no free lunch in regards to mobility

As for APC , IFV  you can see ever smaller miltaries turning ever more wheeled APCs into wheeled IFV roles. the role of APC in practice now seems to be handed down to armored trucks like french Griffon.

Both look like IFVs , i imagine if vehicle packs a turret with anything more than .50bmg its trying to be an IFV doesn't matter itf its actually a turret or just a heavy OWS  ,French VBCI is more of an IFV than APC.

Boxer on the left, what is on the right?

Mr. T (MrT4) said:

As far as i can tell wheels vs tracks were decisions were mostly about costs if not outright acquisition cost then ,lifespan costs

I think logistics and maintanence may be a factor.

In recent discussions of sending Ukraine M270 MLRS or HIMARS, it came up that the wheeled HIMARS has about 1/2-1/10th the maintence needs of the tracked M270. Not sure if thats anecdotal or factual but it stuck out to me. 

For an expeditionary force, having something thats more durable / resistant to breaking down could be as important as offroad capability. 

...

Somewhat related, how capable are these 8 wheeled vehicles if a few of the wheels (say 2 on one side) have been destroyed? Can they still keep rolling?

That could be an advantage compared to a track, which seems like if it becomes damaged disables the entire track until its repaired or replace.