Upgrading military units versus training new ones

[mastrude]

I have units that are two or more upgrades behind. Has anyone analyzed when it might be better to kill them and train current units?

 

[Browd]

The simple gold cost of upgrading vs. buying anew should be readily analyzable, but the wild-cards in the analysis are usually "squishier" questions, like (1) do the obsolete units have promotions that you want to preserve?, (2) does the intermediate unit on the upgrade path require a resource you don't have (or that is in short supply) but the final upgraded unit does not (or requires a different resource that you have in abundance) (e.g., warrior to swordsman to musketman to infantry)?, and (3) if the alternatives are upgrade immediately for gold vs. train new units with production over many turns (assuming you have the best policy cards available for each alternative), can you afford the time to train new units, or do you need the upgraded units now? I've probably omitted other factors to consider (e.g., faith-buying alternatives), but I don't think there is an easy rule of thumb, like "1 upgrade is always worth it, but 2 or more are not".

 

[Tiberiu]

Also, if you want to get rid of some obsolete units, don't just simply delete them (unless you need the little gold they give if it's done inside your territory), but gift them to a City State that you have influence with.
If you can make one major civ attack a CS, you will also be able to gift for 10 influence instead of just 5.
Another use for obsolete units is to farm a minimal amount of XP by sending them to die. Scouts are very good at this, you can suicide attack for 5 xp. Early game it helps get out the first or second great general.

 

[tommytoxen]

depends. the only question is will the newly trained unit have more XP/promotions than the current unit?
if yes then train if no then upgrade

 

[beetle]

I am very reluctant upgrade units that don’t have at least two promotions. OTOH, the main benefit of upgrading is that cities can spend turns on buildings rather than units, and that’s true regardless if the units have decent promotions.

 

[plus]

i always upgrade.never sell.as i always play big games with mods,one of promotiins,and always build barracks,armory in few selected cities,i never sell