Abstract: Methods and systems are presented for collecting fuel vapors in a fuel system that includes a side mount fuel tank. The methods and systems may allow fuel vapors to be captured during filling of the side mount fuel tank. In one example, the side mount fuel tank is fitted with a fuel filler tube that extends into the side mount fuel tank so that fuel vapors may be captured while the side mount fuel tank is being filled.

Abstract: Methods and systems are provided for an evaporative emissions control system for onboard refueling vapor recovery of a heavy duty vehicle. In one example, a method may include adjusting flow among at least two canisters during canister purging, where the at least two canisters are arranged in a parallel loading and unloading flow direction, to increase flow through a higher loaded canister. Flow may be adjusted using a first valve coupled to the first canister, a second valve coupled to the second canister, and so on for n number of canisters and n number of valves, and a balancing valve used to selectively couple the at least two canisters to a fuel tank.