My bud and have had a long running contraversy. I say my black car is not much hotter than his white car. His claim is it is significantly different.
Black car 2003 trailblazer.
White car 2009 trailblazer.
So we did an experiment, will post the chart tomorrow.
Similar color interior, black car a tad darker, both with tinted windows, both parked windsheild out of the sun, no shadows etc. One digital thermometer swapped between cars.
So asking for judges (ie you guys) opinion, what is the opinion of not much hotter vs significantly hotter in your mind, and your guesses on a high of 85degree day, full sun relative temp.
The body wont absorb as much heat,but the sun shining in the closed windows is going to get mighty toasty(a white body wont burn you when you lay your hand on it either)but an auto is a very good solar collector(ought to put coils in used autos and use them for solar collectors)
I feel sure that the white interior would be significantly cooler than a black interior but there are a great many other variables, window tinting being the most significant. The solar heat on the hood and rear deck shouldn’t have any affect on the interior getting hotter but the roof would, depending on the insulation and headliner.
Many years ago I owned a few British roadsters and all had black leather upholstery which would blister my legs if I didn’t close the toneau cover when parked in the sun. Needless to say I closed the toneau and also kept a beach towel over the seat all summer.
Excuse me @Barkydog, I just couldn’t get past the headline re the white interior although I read the full OP. It’s funny what sticks when reading… can I use my age as an excuse?
Maybe this is a trick question. I’ll say there’s not much difference between the two.
I keep a dash vent thermometer in my Lincoln all the time. It’s silver with gray leather seats. In the sun on a hot OK day (100 degrees, etc) that thermometer will read 120 to as much as 140 degrees F.
It’s hard to see a black car being much worse than that.
I dunno, I’ve always had dark cars and dark interiors and its never bothered me, especially with leather, but everyone (nearly) in Florida has a white car that you can’t see. Good thing it doesn’t snow there. No white or silver disappearing cars for me. But I’ll go along with maybe a 5 degree difference. But you need to use two thermometers on the same day, parked in the same locations. You can’t use one on one day and then another car on another day.
I guess when I’ve ridden dark cars vs white cars I don’t notice much difference in the interior temperature. If there is a difference, it is in the temperature of the seats. Dark leather or vinyl seats are hotter to the touch than lighter colored cloth seats.
So I’m guessing the car with the darker interior might be a little warmer, but less than 5 degrees F warmer.
White cars are hard to see against the skyline when you pull out on the road,I buy white,but have been contemplating a orange or funky colored vehicle,so I can find it in the parking lot.(most of the time I never think to look at the signs or or a landmark)
"One digital thermometer swapped between cars"
How do you plan on moving the thermometer without opening the doors and letting all the hot air out?
Are the cars identical, with identical window dimensions and angles? don’t think so.
“windsheild out of the sun” “no shadows” ?? isn’t this contradictory?
Unless you had two identical cars (except for the colors) fully in the sun, closed up, with identical thermometers placed identically and read from outside, this won’t be a meaningful experiment.
edit: plus, the interior color has to be the same to eliminate that variable. Or, if you want the effect of interior color, the exterior has to be the same color.
Swap the thermometer quickly and allow some time to re-establish the peak temperature lost when the door opened. It won’t be perfect but it should be close.
Owning 2 black cars in Florida, I can attest to the fact that they get really hot. Both have vent-shades over the windows so I can leave the windows open 1/2 inch all around. Makes a huge difference.
Here’s an experiment that my class did back in the 6th grade. We took 2 large pieces of cardboard outside our class window in the morning when there was about a foot of snow on the ground. The area was very sunny. We laid the cardboard down flat on the snow…one was white and the other was black. By the afternoon, right before class dismissed, we checked on our experiment. The white cardboard was on top of the snow and the black piece of cardboard had sunk about 6 inches. I own a black vehicle and it’s scorching hot in the summer sun. My wife’s vehicle is always cooler even though it’s dark blue.
You only see the portion of the sun’s visual energy spectrum that’s reflected. The rest of the spectrum is absorbed.
White reflects all of the visual spectrum, absorbing none of the energy. Black reflects none of the spectrum, absorbing all of the sun’s energy.
The one that absorbs the most energy gets the hottest.
Are the cars identical, with identical window dimensions and angles? don't think so.
Not much changed from the '02 to the '09 Trailblazer. Some interior trim is different, and they messed with the look of the grille/etc, but underneath it all, it’s the same truck with the same windows.
Both cars parked in the shade will have the dark car a bit warmer, but not much warmer.
The difference would be much greater is the two cars were parked in full sun. That’s when the black paint is absorbing the energy from the sun and the white car is reflecting the energy. The best test would be to use a digital point and shot temp gauge and just measure the surface temp of the metal on the car. As well as the interior temp.
Hold on, who said the cars would be parked in the shade? Then what’s the point of the test? The whole question revolves around absorption of the sun’s energy by different paint colors, and whether that makes a difference inside the car.
If both cars are parked in the shade, the test is meaningless.
OP said “no shadows,” which I assume means the cars are parked in full sun. But he also said “windshields out of the sun,” which I assume means cars parked facing away from the sun. Barkydog, please clarify.
Great graph! Looks about right to me, Mythbusters did a similar test, got similar results. Temperature rise is about 25% higher for the black car. Significant, but not huge.
