Solar Powered Roof?

The solar cooling control is not as intuitive as it should be. Changing the switch position when the vehicle is off does nothing, but you won't know if the solar cooling feature works until the vehicle is off.

 

Here in Florida it is a must have. Keeps the interior a lot cooler. On some cars when you open the door on a hot day you can't even breathe in them. The solar package does the trick. I have never turned it off. It also comes with the remote A/C. That feature I have never used. it only runs the A/C for about 5 minutes till the battery runs down. Plus I never remember to turn the fan on high when I get out of the car.

 

I have a 2011 IV with solar roof and agree that it's a cool feature, but honestly the solar aspect is kind of a gimmick. I live in SoCal where the solar roof does help to reduce heat-soaking the interior, however it's actually a net fuel waster by adding significant weight, increasing the car's coefficient of drag and reducing it's passenger weight-carrying capacity. Those are pretty significant cons in my view, but a sunroof has always been my favorite part of any car so I'm not complaining.

Perhaps some will recall the first car fitted with a solar roof; the 1992 Mazda 929 introduced a solar roof to cool the car as well as charge the 12V battery. The 929 also featured motorized dash vents that silently oscillated from side to side. Mazda claimed their solar roof reduced interior temperatures by 30% and could fully recharge a battery at 70 percent charge in five days. Toyota's solar roof arrived eighteen years after Mazda's original execution and what's old is new again.

 

Does A/C work for winter? I tried that during cold mornings, it doesn't seem like it did anything.... I set it on auto temp, and have the button depressed. What am I missing here?

 

I was reading the manual and it does say somewhere that the A/C button does not work when the temperature is below 35 F (I'm not exactly sure if 35F is right, but I know that it's supposed to be disabled.

 

Doesn't seem to be any evidence of lost mileage based the anecdotal evidence of users on PriusChat or in the mileage ratings from Toyota.

 

Would it run it when you select defrosters? I know on gasser cars it runs the compressor with defrosters to reduce the humidity.

Mike

 

The a/c technically doesn't run, although I think it will dehumidify. If only I wasn't too lazy to go down to my garage to get my booklet, I know I have the section earmarked....

 

I like my solar roof option. Keeps the car cool in direct sun, which we get a lot of here in Nevada. Technically, the MPG is probably reduced due to the increased weight, but really can't notice it. Overall, my average MPG is better than my former Gen II ride.

 

One experience as a newbie was stepping into the car after a 4 mile run and me being more than hot and something kicking on when I sat in the driver seat and closed the door that cooled the interior was a great surprise. I am not "car knowledgeable" but this was definitely a welcome surprise and I called it my "hot flash detector." Love it, love it, love it!!!

 

92 mpg? On a non-plug in? Wow!!!

 

Is this really true? Is there a noticeable drop in mpg? I'm about to buy and wondering if I should get it. I will be commuting 110 miles/day roundtrip so mpg is important to me. But Sacramento is super-hot so it seems like a useful feature to have... Should I be looking at base III instead and saving myself the money?

 

It might as there's extra weight, but even if it caused a 1-2 mpg drop (I'm picking a # out of the air), please read Car and Driver: Mileage? No, it's Your Gallonage that Really Counts | PriusChat to put things in perspective.

 

Let me clarify what I did with my first Fuelly post - I input the data at the gas station. A ten mile trip home and the lights on the dashboard said 99.2 mpg. I just about died in the driveway - Fuelly came up with the 92 mpg. I think I average 48-57 in the city driving and had 67.9 on the highway prior to Fuelly. I'm two pips down on the gauge and really hate to let it go below half...maybe the next Fuelly input will be more "believeable"... but the car and Fuelly were close... I can't explain it....

 

Weight is a critical component in the fuel economy equation. The solar sunroof adds 66 lbs! The weight-induced fuel economy reduction is based on the percentage of extra weight relative to vehicle weight. Smaller vehicles are effected more than larger ones. You need to pay with gasoline to drag that weight around every single day.

If you're driving mostly on the freeway; the incremental increase in the car's cd may be even more significant.

I haven't done the math but I'd expect the solar roof would account for a reduction of at least .05 - 1 mpg.

Why do you think solar roof-equipped cars are in short supply? If Toyota were importing a significant percentage of cars with solar roofs, they would register a net reduction in CAFE. As it is, I have a sticker on my 'B' pillar stating that the vehicle's load carrying capacity is reduced by ten pounds due to vehicle equipment. (solar roof)

In 2012, Toyota deleted leather upholstery in favor of vinyl. The reason given was weight reduction. What are we talking about with vinyl rather than leather? Let's be generous: maybe ten pound difference? The solar roof is 66 pounds.

The solar roof does help reduce heat soak in sunny climates. So does opening all of the windows for a few minutes when you get into a hot car, and you still have $3,800 in your pocket. At $4/gallon, $3,800 = 950 gallons x 50mpg = 47,500 miles.

So why do I own a solar roof? I bought my 2011 used; it was equipped with a solar roof, and I didn't pay a premium for it. To buy one new, you need to understand that you're paying $3,800 for the cool factor. It really does very little for a lot.

If you're going to keep the car longer than the new car warranty, the $3,800 premium could well be a down payment. Toyota thinks their spare parts are VERY special.

 

Unless Toyota has managed to suspend the laws of physics; a 66 pound weight adder HAS TO exact a fuel penalty.

 

We were discussing this in another thread but the weight was in regards to almost full fuel tank to almost empty. A few of us took a stab in the dark and guessed that for every 40-60 pounds that is another 1 mpg lost. Obviously that is extremely rough math but you get the idea.