Most BRIO battery engines cannot easily ascend the standard ramp tracks while pulling loads. Here the Freight Battery Engine and the 4WD Rechargeable Engine both stall out while trying to pull three loads up a standard ramp.
The Freight Battery Engine surprisingly does better than the 4WD engine.
You can remove the unsightly, white stress lines from plastic parts using a heat gun. Heat the plastic slowly and gently and they will gradually disappear, taking care not to heat so aggressively that they actually melt.
Here, I show the technique on a BRIO #33382 Windmill. The large, plastic sails are easily bent both during handling and in storage, and it's almost impossible to find one without marred plastic.