The Environmental Protection Agency is issuing new window stickers for 2008 vehicles to offer more accurate fuel economy information.

And although they're not based on real world driving, it might create a little sticker shock.

2008 models are now on showroom floors, along with sticker numbers. The EPA's old methods of testing mileage was a bit out of date.

Sean Comey with Triple A said, "They didn't use air conditioning they didn't drive in stop and go traffic they didn't carry any weight in the car, just not the type of conditions that people drive in now."

So the new numbers will be based more on real-world driving.

Now unfortunately that means those numbers are down. Especially on Hybrids.

"The estimates for the EPA for hybrids were much more inflated that for gasoline only cars."

But that doesn't mean sticker shock says Toyota's Chip Fong.

"I think that a lot people know that the sticker numbers are a little bit inflated."

So the 2008 Prius estimate is six to twelve miles less than before. Expect SUV's to be two to three miles less.

"We're just switching over from the 07 to the 08 model, buy so far it doesn't seem to affect the buying decisions."

Overall, expect a 10% difference for most new vehicles.