The National Wildlife Federation released a study that says the first-ever fuel efficiency standards for heavy vehicles such as semis, garbage trucks, buses and heavy-duty pickups will save owners $35 billion in fuel costs over the life of the vehicles. Fuel consumption will be reduced by 7 — 20%, depending on the class of vehicles. The federal rules will take effect in 2014 and run through 2018. Fuel economy of large trucks and vans will increase from 14.9 miles per gallon in 2010 to 16.7 mpg in 2018. The changes will cost manufacturers $8.1 billion to build the more efficient vehicles.