I want my Solar Roof, but Toyota won't let me buy one!

OK, what's going on here. Does anyone know why if you purchase the solar roof package (IV), you can't get:

1. Intelligent parking assist
2. Lane keep assist
3. Pre-Collision System
4. Dynamic Radar Cruise Control

This makes no sense. I wanted a loaded Prius with a Solar Roof. This does not compute!

Anyone know why there's this seemingly arbitrary limitation?

There have been lots of posts on this - I think the bottom line is that goodies = additional weight and additional weight = lower fuel efficiency.

The main issue is that Toyota decided that they absolutely must have one EPA rating for the car, and that rating had to be over 50 mpg. I'm not sure if there is any extra cost involved or whatever, but plenty of other automakers have different EPA estimates for the various trims.

They also decided they absolutely must only offer only 10 configurations for the vehicle in the US market. So sliding a nav radio in the same spot where a non-nav radio was and hooking it to the same speaker wire counts as a entire configuration just as much as cutting a hole in the roof does.

Now, the issue you are asking about concerns the weight of the car. The sunroof package adds 65 pounds to the car. The advanced electronics package that you described is ONLY available in the Prius V, which has the 17" wheels (due to the configuration limit the 17" wheels and technology package are ONLY available in V trim in the US). These wheels weight 24 pounds each, up from 16 pound 15" wheels in the lower models. The larger tires are about 2 pound heavier each, so you have ~40 pounds of unsprung weight added in the V. Unsprung weight counts for roughly 2-3 times the equivalent sprung weight (the sunroof is sprung as it is above the suspension).

24 pounds is very heavy for a 17" wheel. That could have easily been reduced, at a price of course. In some countries you can get the sunroof and advanced technology package together, but not with the 17" wheels. So much for the factory efficiency of only building 10 configurations.

Short version is you have to choose between the 65 pound sunroof and solar panels or the 40 (unsprung) pound wheels in order to make Toyota's mpg cutoff number.

Accordingly, when are you springing for your IV with SR and some ultralight 17" aftermarket rims?

I went to the TireRack.com web site last night just for Dreams/fun to check out the tire/wheel packages for my IV. Found a sweet set. The 17" rims were only 14 or 15 lbs. (search by weight) and you could view them on only a 2004 model Prius but they looked sweet!. Now, only hurdle is price. With TPMS and wheel locks came to just shy of $2000.00. I wonder, if I convince my wife that we need the bigger tires for winter time/increased traction/better handling, will she be ok with me getting them?? Dang, they look so cool!

I think it is more so that they can add it in the future.

You could try to convince her of this, but in fact, the lower profile tires greatly reduce the traction in snow. I live in Chicago, and still chose to buy buy a Prius V, so will deal with that, but the truth is they are not the best for the snow.

Umm, never? Already bought a III, wish I bought a II. Don't care for leather personally and don't need nav so I wasn't about to throw money away for a lot of options I didn't want anyway just to get the sunroof and wheels. When these tires are done, I'll probably get some mid range wheels, but maybe I'll just put the money towards my toy cars instead of upgrading the appliance car. Sunroof is definitely coming though; I don't ever use the remote start to cool the car as it is so the solar vent and remote AC is not an issue for me.

Also, you don't need to buy the TPMS for aftermarket wheels, you already have them on your car and just need to be mounted on the new wheel. Just have them mounted at your local shop, shouldn't cost much if anything to have them take them off the old set for you if you are having them mount and balance the new wheels. It even says this on the tire rack site. If you are buying a second set of wheels for snow tires or something then you will want to.

No, accordingly has it right. I got this same explanation from the Prius chief engineer when we talked to him in Detroit.

Tom

Congrats, now add it to your profile details

Assuming the wife of a Dr. is smart, come up with a better, more valid argument like you want to put skinny snow tires on the existing 15" and use them as dedicated winter wheels.

Seriously of course they are going to tell you that. Next year they will add it as an option for the 2011. In fact I would be seriously surprised if the solar roof isn't eventually standard on every option package except maybe the base I model, similar to how the smart key option became with the Iconic.

It's a marketing issue, not a technical one, so sure, Toyota can change its mind. If they do, they will have to live with multiple EPA figures, which is something they don't want at the moment.

Tom

Ahhh, great! I like this, then I get the 17" wheels the rest of the year! (probably longer in NE AZ - we do live at 7000 ft. though so dedicated snow tires would be smarter!). And of course she's smart, she married me right, LOL! Of course, since she's so smart she will probably just say, "Don't worry about it. On those really snowy days I'll just let you take my car all day (Subaru Outback)." Dang, no 17" rims for me!

i wanted to get the same...so i asked toyota why you couldnt get that and they said fuel economy...but if yiour paying for it why should they care...

As pointed out in the previous posts, it screws up their EPA mileage figure. Toyota wanted a single figure to publish for mileage.

Tom

Hi Bob:

Don't know how close you are to Canada, but if you wanted Solar Panels plus Intelligent parking assist, Lane keep assist, Pre-Collision System and Dynamic Radar Cruise Control you can come here and get what you want.

For $38,100 CDN (plus tax) you can get the Technology Pkg which is the top of the line here. You get the Advanced Tech, Solar Panels, Nav, Backup Camera, Leather Seats and so on. Granted, it doesn't include the Fog Lights or 17" tires but you can add those afterwards yourself.

Food for thought..........

Edward
Marystown, Newfoundland
Canada