The company had originally proposed the capacity of the Trans Mountain pipeline would increase from 300,000 barrels a day to 850,000 but is now putting the number at 750,000.
Kinder Morgan spokesman Andy Galarnyk says the revision is the result of contracts the company has signed with its customers.
But Ben West of the Wilderness Committee says the key issue is the total potential capacity of the expanded pipeline, which ships tar sands oil to a tanker port near Vancouver.
He says when the company applies to the National Energy Board to expand the line it should be honest and base the application on the total potential of the project, which faces stiff opposition over the risk of oil spills along the route and from increased tanker traffic on the B.C. coast.
West also says it's inappropriate for Kinder Morgan to be signing contracts before the project is approved.