XL engines are very expensive and are a death trap on the wrong mech or just pointless because of slots. So I want to give the noobs some 1st hand advice on which mechs xl or std is right for.
XL engines are lighter for the same speed and power but put vital engine components in the side torso for 3X chances of you mech sniffing the ground.
I cap my discussion here at XL 300 as that is the max engine I have to give good data. XLs are expensive so I worry about cross compatibility.
All of this is opinion based on my personal experience.
Stalkers.
Decent torso hitboxes but you will run out of slots before you really get anywhere with your dreams of a fast Stalker with a crushing alpha. This is a slow mech but has the Battlefield survivability of the Hulk. The sight of you will cause panic amongst your enemy, want to live up to that step up a few STD engines and go with endosteel and double heatsinks. Or you can drop 6 large lasers and a STD 300(62.9kph) in a 4N/3F and have some laser boating fun that makes them run from you. Please please please check your friendly fire. I swipe in the back from that things alpha can kill a lot of mechs.
Jenners
Probably the most slanted center to side torso hit boxes in the game. The JR7 F with an XL 300 can and elite tier speed tweak(10% speed increase) can go 152.7 and still pack 4 medium pulse lasers. With speed tweak XL 235 119.6 kph XL 245 124.7 kph
Catapult
Can't remember the engine cap on this one But to big with a STD and bye bye Lrm boat dreams, XL and its slot issues or ton issues if you don't upgrade endosteel.
Another "its not Nascar" mech, if you really want to be affective. Its a heavy so 64kph ain't bad from the stock engineand gives good survivability.
Kintaro
XL all the way. Great side torso hit boxes. Endosteel STD Armor and double heat sinks you have plenty of slots for a lot of goodies on a medium mech. They can sport up to a XL360 but an XL 300 gets you hopping along at 88.4 kph/97.2 with speed tweak. The KTO 19 with an XL 300 can carry 2 Extended Range Large Lasers, 4 Long Range Missile 5, 2 double heatsinks in engine slots and 5 tons of lrm ammo. Heat management 1.24. Throw in an advanced zoom module and you are a fast nimble sniper. With the STD 275 you could only get 1 ERLL the 4 LRM5s, 4 tons of ammo and 1 double heatsink. 81ish kph
Wolverine,
I had much better luck with a STD Engine in the 6R than XL got a few pure side torso deaths from snipers, 100% health and then boom your dead. I chock this one up to thin armor more than hitbox.
The Thunderbolt 9SE(C) that you have all been trying so hard for.
XL, the side torso hitboxes are ok tonnage is your problem here, the stock STD 315 weighs 28.5 tons an XL300 weighs 15.5 and only loses around 7 kph. XL 315 weighs 18 tons no speed difference over stock. As far as I know this is the only way, survivability be damned, to make use of all this mechs quirks.
Edited by Tractor Joe, 30 March 2015 - 11:12 AM.