Since Forestry has left us, I think this useful feature could use its own special treatment. When right-clicked without a BC wrench, a GUI appears. Two adjustable settings and an item slot are shown. The first is the activity slider. It's options are ON, OFF, or REDSTONE. The first will always keep on the engine on as long as EU is supplied. The second keeps the engine off until changed. The third makes the engine run when a redstone signal is applied. The second is the power slider. The options available are: Ultra-Low, Low, Medium, High, and Ultra-High. UL uses 1EU/t to generate 0.25MJ/t. L uses 8EU/t to generate 2MJ/t. M uses 16EU/t to generate 5MJ/t. H uses 32EU/t to generate 12MJ/t. UH uses 64EU/t to generate 25MJ/t. The item slot accepts any IC2 portable EU storage item and will discharge to power the engine if it is trying to operate but is not receiving any EUs. I'm not dead-set on the EU:MJ ratios because I'm not sure if it should be encouraged to have more power output for efficiency or having more engines.