Consumer Reports is giving consumers fuel economy numbers for HD trucks, and is lobbying Congress to do the same.

Light-duty trucks, the 150 and 1500 sizes known as half-tons, tear up the sales charts every year, and the companies that make them are adding smaller engines, more gears, turbos, and even diesels to try and improve their fuel economy figures. But bigger pickups are still big sellers. Between Ford, Chevrolet, GMC, Ram, and Nissan, nearly 400,000 three-quarter and one-ton pickups were sold last year.

Ram 2500, Silverado 2500HD, and Ford F-250 can haul more stuff, but take a look at their window stickers and you’ll see something missing. An EPA fuel economy label.

That’s because trucks over 8,500 pounds gross vehicle weight rating – the maximum allowable weight of the truck, passengers, and cargo – don’t require fuel economy on the window sticker. The fuel economy rules were drafted decades ago, long before anyone thought that average consumers would start buying such large trucks. So while automakers calculate the numbers for their Corporate Average Fuel Economy figures, the data is never posted.

SEE ALSO: Ford To Build Hybrid F-Series Pickup By 2020

Consumer Reports and Consumers Union, the policy and lobbying arm of CR, want big-truck economy to be public.

“Heavy-duty pickup shoppers shouldn’t be left in the dark when it comes to fuel economy,” said David Friedman, director of cars and product policy and analysis for Consumers Union.

“NHTSA (National Highway Traffic Safety Administration) and the EPA should get this information to consumers as soon as possible and Congress should make sure they have the funds they need to do so.” Friedman added.

So the Consumers Union is calling on Congress to require the EPA to make fuel economy, emissions, and expected fuel costs for heavy-duty trucks available to the public, the same as they are for smaller vehicles.

As far as the testing, which paired diesel three-quarter ton trucks against their half-ton siblings? Unsurprisingly, moving to a bigger diesel doesn’t make up for the fuel economy of a smaller truck with a gas engine.

It was close, though. The F-250 6.7 diesel scored 15 miles per gallon in testing versus the 16 mpg of a 3.5L EcoBoost V6 F-150. It was the same with the other trucks. Nissan’s Titan XD scored 15 mpg, one behind a gas Titan, Ram 2500’s diesel scored 14 mpg to the 1500 Hemi’s 15, and Chevy’s Silverado 2500 diesel scored 14 mpg to the 5.3L V8’s 16. Note that the numbers are based on Consumer Reports’ own testing, and does not compare directly to an EPA rating.

Consumer Reports