SU attachments and trucks

[squatter]

Talking from a Soviet perspective here, I am wondering about the optimal use of SUs attaching directly to combat units as far as truck useage is concerned.

I'm sure I've read elsewhere advice not to attached motorised SUs to non-motorised combat units as this will place a truck load onto the combat unit that otherwise has low truck requirement.

But logically it seems to me that the SU in question will require the same amount of trucks whether it is attached to a motorised or non motorised parent unit? Therefore why should it matter to what combat unit a motorised SU is attached since the same amount of trucks are being used (obviously I am missing something here).

Following on from this, if truck useage is an issue when attaching motorised SUs to non-motorised combat units, which SUs are we talking about here:
Motorised inf obviously.
Tank SUs?
Do AA and AT SUs require problematic truck quantities when attached to inf?

And following again, is the truck issue the same when you attach motorised SUs to both INF and CAV equally?

Thanks

[loki100]

key is a SU is motorised in one of two situations.

Its coded as motorised on the unit tab etc
Its directly attached to a motorised CU

So if you put a non-mot rifle brigade or AA unit into a Tank Corps then the first thing it will do is to find trucks. You'll often find this is inefficient when compared to the specifically designed formation. So a Soviet rifle brigade that gets motorised this way will demand more trucks than a Soviet mot rifle brigade (it also brings more combat power so there is an obvious trade off)

The inverse doesn't apply, so a SU doesn't trigger any change for the CU, so putting saw a mot flak unit into an infantry division makes no difference to the division's inherent truck demand

cavalry are non-mot so the approach above applies when they gain direct attachments.

[Q-Ball]

Loki is spot-on, what you really have to watch is attaching non-motorized SUs to motorized units; it will draw trucks to do that. If you are the Soviet Union, it is unlikely that you can afford to do that much prior to mid-'43 or so; trucks are better used for motorized units that need them like Tank Corps, Rocket Div, etc.

I attach motorized SUs to non-motorized units all the time, but in every case it's TANK units. When Soviets have alot of Tank and SU units, you should liberally attach them to Rifle Corps and Cav Corps as extra oomph

Every Cav Corps should get 1-3 Rifle Brigades as SUs; it adds extra punch to the CAV, and costs nothing in terms of trucks. I usually go 1 Tank Bde and 2 Rifle Bde, but that's just me

Mech Brigades are expensive in terms of trucks and AFVs, but they are multi-role units; you can really beef up a Tank Corps with Mech Brigades (or a Mech Corps, effectively DOUBLING it's combat power if you use 3 Mech Brigades)

[squatter]

Thanks guys - I had obviously got it the wrong way round in my head!

All makes sense