It doesnt matter if you have DHS or not.
Your Mech needs 10 Heatsinks in order to be combat ready and fully operational.
This said the raw number of Heatsinks is more important then theyr heatefficiency.
As Crazysteve said:
IF you install DHS the heatsinks inside of the engine (not the ones that can be put manualy inside the Engine)
are 2.0 and all the others 1.4.
Wich makes DHS more effective when you use it with engines that have 10 internal heatsinks.
Especialy in the lower engine ratings its a cowtrade.
If you want more Tonnage and the only way to achieve this is to downgrade your engine, you may get a few tons, but you most likely loose an internal heatsink.
So you lose a 2.0 heatsink wich makes no sense if your heatefficiency is so bad that you need to install another regular heatsink.
Engines get per 25 points of rating an internal heatsink. So a 250 rating Engine has the full 10 internal heatsinks.
Then at 275 you get an extra Space INSIDE the engine for a Heatsink (wich is most likely used duo the lack of critical slots instead of tonnage) and so one. But still, if these are DHS they only have a 1.4 rating.
If you build your make it makes sense to check some data before.
First:
What should my weapon loadout for this mech look like?
How many tonnage do I have left?
What Engines can I use with this?
Is it to slow?
Is my Mech to hot with this Engine / tonnage left?
Can I trade a ton of Heatsink for an engineupgrade granting me another 2.0 Heatsink?
etc.
And there are some basic rules.
For an XL engine for example, never use a xl250 because you can get an 255 for the same tonnage.
Not much but a little boost of speed.
http://mwo.smurfy-ne...#module_engines