I brought this up after patch 1.05 and was told they definitely do, but since then i believe they have modified it, but I think it is still a problem today 1.09. I think it might be because they always have perfect tyre temps. Even when they power out of the slow corners with perfect traction, their temps are perfect, so the wear is minimal every lap. Which by then end of a long stint is a huge advantage. And my findings are all on Grand prix mode. Don't want to start a career when it's clearly not working properly.
Edit. Should have been patch 1.08
https://answers.ea.com/t5/Bug-Reports/AI-gaining-Massive-Speed-on-the-straights/m-p/11656702/highlight/true#M4472