Legogamer

Lets talk about IRL again Some liquid fuel engines irl don't produce smoke trails , but some does. I guess the mod creator is going for the no smoke only.

Actually the mammoth and vector plume actually make sence. If you look closely, you can see clear red-ish plume below the blue one and some of the most powerful rockets in the real world have engine plume similar to those. And personally they are my favourite plume!