I changed my stock headlight bulbs so I had to remove the plastic panel in the engine compartment. It was easy enough to remove but is the panel really necessary? It doesn't seem to protect anything. Is it a dust shield or an air flow devise? Or something else?
I'm sure Toyota wouldn't have placed the panel there if it served no purpose. I'd guess it assists with maintaining correct engine temps and/or aerodynamics.
I don't think that the panel is "necessary". The Classic model does not have the panel. However since the panel is easy enough to remove and replace, why not replace it so that your car maintains its factory-new appearance.
I think it's mostly for looks, maybe a little bit to keep you from reaching down there while the fans are running. Mines been off for about 3 years with no untoward effects.
It can't be for aerodynamics or looks -- it's a plain black plastic panel under the hood. Don't know what its intended function is, but if I remember correctly its flat surface is large enough to serve as a little shelf to hold some hand tools, lunch and drink while you're working under there. Joephu - hey what did you replace the stock oem bulbs with?
That's funny I think it's for aesthetics too. My Saab 9-5 had a very similar panel around the oil filler cap and throttle body. One day I broke a clip and just tossed the thing out. I may do the same once my Prius is past warranty. But then I guess I will have to figure out how to keep my radiator cap clean. I actually replaced the OEM bulbs with Philips X-Treme Power. I had these on my Honda CR-V. I use to use Slyvania Silverstars but I find these slightly brighter. Also the Silverstars only lasted 9 months on average and I was told these last much longer. They are definetly much brighter over the OEMs.
Yes, I have the Phillips X-Treme Powers. They have to be the brightest aftermarket halogens out there. But don't be surprised if you only get 6-12 months or 6-12k miles use out of them. The anecdotal info here isn't much, but I think usbseawolf2000 only got around 6k miles from one bulb and around 8k miles from the other. Tideland Prius also has them and he's in Canada so they're always used as DRLs. So far, I think his are both working after around 6 months. I only drove my Prius 2800 miles last year. So I expect mine to last a few years, if not many miles.
Given the amount of crud that accumulated on my panel over the winter, and the fact that the front inner hood seal comes down pretty firmly along it, I would think that it *does* help keep the engine area a little cleaner. But the engine still got its own share of crud anyways, probably from underneath. . _H*
I think it may also be used for cooling. At least on some vehicles similar plates are sold as an upgrade for radiator cooling. It prevents the air from "escaping" at the top. Similar to this