We just finally got our 2010, love it, and are now trying to make it as nice as possible. The model we bought - the S (second from bottom Japan model) - does not include the underbody cover. We weighed the price difference between buying the next model up and the S and didn`t feel that it was worth it just to get the underbody cover. Too much additional stuff we didn`t really need or want. Has anyone driven around without the cover? Were things noisier or was there no perceptible difference? The car is fairly quiet, but we wonder if it would be worth it to pay for and have the underbody cover attached...? I know that it has an effect on the mileage, etc - but we`re more concerned with any differences in noise level. We were thinking of adding some deadening, but if the underbody cover provides a fair amount of road noise reduction and is cheaper... well, we could probably add the cover and a minimal amount of deadening to get a good result without spending much more (and get the other bonuses of the cover). If there is very little difference when it comes to road noise, then we won`t bother with the cover.
I had no idea they made a model without the underbody cover. I learn something almost every time I read these forums.
I thought the purpose of the under-cover is for aerodynamic reasons. I doubt it will lower the noise because the road noise is coming in from the tires through vibration.
I thought all U.S. Prius have this underbody cover that makes it look like the bottom of a toy car. Japan is different? I wonder what the coefficient of drag is without the cover.
It isn`t ALL the cover that isn`t included. I believe it`s just the under body cover - the under engine cover is standard on all the models. From what I understand the cover is split into 3 different parts, the under engine cover, under body cover, and a cover for under the back area. I`ll have to try to get a picture of the underside of our car to see where there are and aren`t covers. I don`t think the fleet cars in the US have all 3 parts either. The very lowest model that isn`t sold to normal consumers doesn`t, if I`m not mistaken. I too thought they all came with the full set of covers, but after putting in the order for ours found that the S also doesn`t. All the higher models do include it. We decided not to go for the higher model as it just costs more for a bunch of stuff we don`t need - like cruise control, aero parts, etc. You can buy it extra, but it comes in a set with rear aero parts - something we don`t need. The car is low enough as it is... I honestly don`t think there is a huge difference when it comes to actual mileage as all the Japanese tests for mileage are done on the L model, which is the one below the S - and it doesn`t include those extra covers either. The dealer (they`re actually trained and know what they`re talking about here) said that the additional covers do reduce drag a tiny bit, but in terms of mileage it is pretty much offset by the weight of it. The important one is the under engine cover (included on all models). I guess I should have been clearer in the way I wrote it. The under engine cover and under body cover are different things.
@thbjr & 32kcolors: http://priuschat.com/forums/knowled...andard-optional-equipment-some-countries.html S Touring Selection: ¥2,450,000 S equipment plus 17" Alloys on P215/45R17 Tyres, Auto-Levelling LED Headlights w/ Headlight Washers, Euro-Tuned Suspension, Underbody Covers and Spoiler Only the Touring Selection model in Japan gets the underbody covers and rear underbody spoiler (that's the black plastic bit at the bottom of the rear bumper) Tamyu: I'm not sure. Toyota seems to make a lot of these subtle additions to the car for aerodynamic purposes. For example, we asked what's the difference between the moonroof and non-moonroof models because you lose that curvature in the roof when you select the moonroof option. Apparently, there isn't much difference in drag. I'm just wondering if Toyota hopes that the sum total of all these minor additions will result in a decent reduction in drag.
Almost right. There are three under covers. The under engine cover - under the front and engine. Then under floor cover, center and rear. Center is, well, center. Rear is the black plastic below the back bumper. The spoiler listed as equipment for the S Touring, etc, is actually a spoiler. It attaches to the back bumper and is the same color as the car. Like this. I don`t know if it is standard outside Japan.
Nope. Ours is a LOT smaller than what you posted and it's black, unpainted but it is standard across all models.
A difference between U.S.-based trim I and trims II-V is the "underbody spoilers and spats" according to the Prius Team.
Very interesting, I have been considering removing the center under body covers because they rattle. I don't think they were installed properly, some of the fasteners are stripped out where they go into the floor pan. I may be able to fix them by putting in new fasteners and insulating them with some foam rubber stuff, but I'll leave them off a while anyway and see if it seems to effect mileage. I think the front cover and the engine cover are the important ones, the center ones may be like the plastic rings on the 15" wheels?
I did some fuel mileage tests with the 4 under body covers removed today. I will post the result in the mileage form but the short version is there was no difference in mileage at 70 MPH. I was also unable to detect any difference in road noise.
Thank you so much for testing this. Maybe the weight of the covers matches the amount of improvement....
I just found out my car is a model one and it does't have the underbody spoiler. Does anyone know how much of an effect this would be to the aerodynamics of the car? I tend to go around 70-80 mph on the highway (not aggressively). Would it be worth 125 to get a used set of the undercover for the midsection of the car off ebay? For some reason it kinda bothers me that it is missing, I guess I need some kinda mathematical/scientific reassurance that I'm just wasting 125 dollars.
So I was thinking on a drive home and correct me if my math is wrong. At $125 for the underbody spoiler I can get aprox 35.7 gallons of gas. My last trip (90% highway) from a full take w/ avg mph at 55 i got 47 mpg. So with that I multiply it with how many gallons of gas I could of purchased and I get 1,678 miles I could of drove w/ $125 dollars. So this is the part I'm guessing now, the underbody spoiler might save me I don't know 1 mpg or 2 mpg? I'll go w/ 1 mpg to be conservative, it might actually be less. So if it's 1 mpg I save then I would need to travel 1,678 miles to break even? 125 ($) / 3.50 ($/gal) = 35.71428 gallons 3.5714 gallons * 47 miles/gallon = 1678.57 miles 1678.57 miles / 1 mpg saved= ?!!? units don't make sense.
