I just bought a 2008 Prius and drove it about 1,000 miles on the freeway from California to Washington State - home. I loved it all, except that it seems to have an excess of road noise. Anyone figure out a cure for that? Some kind of undercarriage coating? Special tires? It has the standard 15 inch wheels and original tires on it with now 22,000 miles on them. It's not "that bad", but, if there is something that would quiet it a bit, I'd probably do it. Thanks, Tom
Not special tires, just different ones. The OEM Goodyear Integrities are great for MPGs and dry traction but not so good for noise or snow. People like Nokians, Michelins, GY Assurance FuelMax. There are zillions of posts of discussion. "Search" is your friend :_>
You can also add sound insulation to the inside of the car: inside the doors, headliner, etc. A good auto sound store can do this. Will make your car stereo sound better, too.
Depends on the type. If you are using mainly the tar type mats, you are looking at roughly 20-40lbs of extra weight depending on how exteme you go, ie removing all the carpets, door panel, headliner and having a hayday with the stuff. Changing tires will reduce road noise as mentioned before.