[pepo]

Hi all, it is a well known science fact that the "blacker" a color the hotter it is under the sun due the light (UV/IR rays) absorption that turns into heat. This is because while white does a pretty good job on reflecting such light, black on the other hand absorbs it. Let's leave it at that.

Now I live in South Florida, where to me it feels like summer all year. At temperatures averaging over 85 my Black Sapphire F30 gets too awfully hot even though the interior is red leather -not black. I don't like heat while driving and I'm trying to find ways to avoid it, there are a few; but I have this theory in particular that haven't found an answer or opinion on:

Based on the premise that light needs to be reflected in order to avoid heating up; could a very shiny wax application on the exterior help reduce the temperatures of the car? The theory being that the more it looks like a mirror the less light is absorbs. Does this make any sense to anyone? Any opinions on this? Have anyone experience something similar? What are your thought?

Cheers

[M2Rush]

Wax does help a little but you can try to turn on your Parked Car Ventilation in idrive, tint your windows, buy a sunshade. If your car is still too hot, you can open just one window and on the opposite side you open and close the door a few times, this will force all the hot air out of the opened window.

[Billfitz]

Most heat gain will be from the windows, not the sheet metal. Tinting with ceramic tint film is the best way to deal with that. BTW, heat is primarily sourced from IR, not UV.

[pepo]

Originally Posted by M2Rush

Wax does help a little but you can try to turn on your Parked Car Ventilation in idrive, tint your windows, buy a sunshade. If your car is still too hot, you can open just one window and on the opposite side you open and close the door a few times, this will force all the hot air out of the opened window.

Great ideas! I'll try the idrive venting (did not know that was there). Loved the idea about slamming the door. Will put into practice.

[pepo]

Originally Posted by Billfitz

Most heat gain will be from the windows, not the sheet metal. Tinting with ceramic tint film is the best way to deal with that. BTW, heat is primarily sourced from IR, not UV.

Hi, already have tinted windows from dealer but not sure if they have ceramic film. Perhaps I should add screens. And you're correct IR feels hotter, already edited. Thanks

[rlmesq]

I replaced a BSM car with MGM when my lease ended. It seems a lot cooler in the hot Northern California sun.

Temperatures "averaging over 85 degrees?" Ha! We had a whole month where I don't think it was that cool at night.

It was so bad that the Velcro on my floor mats came off. I finally bought some Lloyds Ultimats, which use quarter turn plastic anchors.

[pepo]

Originally Posted by rlmesq

I replaced a BSM car with MGM when my lease ended. It seems a lot cooler in the hot Northern California sun.

Temperatures "averaging over 85 degrees?" Ha! We had a whole month where I don't think it was that cool at night.

It was so bad that the Velcro on my floor mats came off. I finally bought some Lloyds Ultimats, which use quarter turn plastic anchors.

I thought that would be the case, although some seem to think exterior color does not make a noticeable difference. Did you keep interior color? On my last BMW the door handles actually melted. Maybe I'll get a temp gun and do some experiments.

[Billfitz]

The exterior color does make some difference, but not a major difference, as most of the heating of the sheet metal is radiated to the environment, not the car interior. The same insulation that reduces sound transmission into the cabin also reduces heat transmission. IR passing through the windows heats the interior parts directly, and that can only radiate into the cabin.

[Soul_Glo]

Seat covers if you are wearing shorts.

Car cover if you can. Decent one that acts like SPF for your car.

Parked in a secure location like a secure work car park? Then crack the windows open an inch all round to ventilate.

You can always spray a bit of water on some surfaces like a hot steering. It will evaporate and help with cooling.

Park in the shade.

Solar powered ventilation?

Agree with the window tinting idea.

Wax wise. Collinite 845 is a great insulator wax. Used on air plane wings and the likes. It might be worth contacting Collinite to see how many layers would help provide some kind of heat shielding property. Or get a decent ceramic coating.

[Billfitz]

Collinite 845 has electrical insulation properties, not thermal.

[ScarecrowBoat]

Originally Posted by pepo

Hi all, it is a well known science fact that the "blacker" a color the hotter it is under the sun due the light (UV/IR rays) absorption that turns into heat. This is because while white does a pretty good job on reflecting such light, black on the other hand absorbs it. Let's leave it at that.

Now I live in South Florida, where to me it feels like summer all year. At temperatures averaging over 85 my Black Sapphire F30 gets too awfully hot even though the interior is red leather -not black. I don't like heat while driving and I'm trying to find ways to avoid it, there are a few; but I have this theory in particular that haven't found an answer or opinion on:

Based on the premise that light needs to be reflected in order to avoid heating up; could a very shiny wax application on the exterior help reduce the temperatures of the car? The theory being that the more it looks like a mirror the less light is absorbs. Does this make any sense to anyone? Any opinions on this? Have anyone experience something similar? What are your thought?

Cheers

Wax is just going to help trap and insulated the metal body as well as providing another layer for converting the light to heat. Your best options are:

1. Good tint
2. Sunshade
3. Leave Florida

You're trying to be too clever. You bought a black car in Florida just get a sunshade.

[Soul_Glo]

Originally Posted by Billfitz

Collinite 845 has electrical insulation properties, not thermal.

UV and IR according to the data sheet so heat resistant properties... as well as to protect against electrical fire and explosion.

[Billfitz]

It will have 'protective' properties in the UV and IR wavelengths in that it is reflective, but so is any wax or sealant.

[stylinexpat]

This is why I did not buy a car with a black interior this time around