Two new studies rate the voice-activated dashboard infotainment systems of six major automakers and the Apple iPhone’s Siri voice command system according to how much distraction they create for drivers. Apple and Google are working with automakers to mesh smartphones with infotainment systems so that drivers can bring their apps, navigation and music files into their cars.

The studies, both by the AAA Foundation for Traffic Safety and the University of Utah, rated the systems on a scale of 1 to 5, with 1 representing no distraction and 5 comparable to doing complex math problems and word memorization.