How dirty is a car interior?

You’d be surprised by this news, for sure. Roughly 700 different strains of bacteria are living in your car’s interior. This data is based on a study by, which conducted a survey to 1,000 drivers in the U.S. The study aims to learn how often car owners clean the inside of their vehicles.

Our car interior is where we spend most of our time on the road. So much so, that most of us eat on the go. There even are instances when passengers, especially kids, take a leak using a wee-bottle during the trip. While these activities may sound normal, such actions could and would result in rapid bacteria build-up in your car – yikes! 

CarRentals' survey result

Unfortunately, we have been exposing our immune system to these harmful foreign bodies without even knowing it. According to CarRentals’ research, only 32 percent of the 1,000 subjects clean their interiors—rarely. These subjects claim that they sanitize the cabin of their car once a year. Even worse, 12 percent responded that they’ve never cleaned their interiors. 

Eating/drinking in car

Among the various causes of germs in cars, food ranks as one of the most likely catalysts. That debris of potato chip you’ve bitten and cracked to pieces over a week ago, the coffee your partner spilled on the seat, and even the drips of ketchup are what breed the bacteria in your car’s interior – developing to a colony after just a matter of days. Well, we couldn’t help but wonder, “what more after weeks; months; or even a year?” Not only does eating inside your car distract drivers, but it also helps in spreading the bacteria.

steering wheel is dirtier than toilet seat

To measure how filthy car interiors are, bacteria were measured per centimeter, or colony forming units (CFU). The results were then compared to public surfaces that are mostly touched on a daily basis. Get this, the average steering wheel has 629 CFU per square centimeter – dirtier than some of the most often touched surfaces.

Surprisingly, its filthier than the average cellphone screen (100 CFU), public elevator buttons (313 CFU), and even the average public toilet seat cover in America (172 CFU). Seems like you won’t be seeing your steering wheel the same way as before after learning this, will you? 

Bacteria-infested areas in your car

You now know that the interior of your car is a home for thousands of bacteria. However, here’s a clear mapping of the most bacteria-infested areas in your cabin. The most contaminated part is none other than the steering wheel, where the driver’s hands rest 100 percent of the time while driving. Running second are the cup holders with 506 CFU, while seatbelts catch up with 403 CFU. Areas with mild infestation include the inside door handle, gear shifter, and audio control dials. 

Cleaning your interior

According to CarRentals, there are proper ways in suppressing these bacteria from spreading all over your cabin. Follow these and you wouldn’t be exposing yourself to possible illnesses caused by the various types of bacteria lurking inside your car. Remember, cleaning your cabin on a regular basis may sound like a little too painstaking but it’s your first defense from getting exposed to harmful germs.  

  • Sanitize – clean the most touched surfaces of your car with sanitizer wipes or sprays. 
  • Change air filters – regularly replacing the air filters and spraying disinfectant into the intake vent removes germs that could be excreted to the cabin once the vents go operational. 
  • Clean your key/key fob – your car key is considered to be one of the most touched accessories of your car, as it can also be handled by other people who use or may use your car. Wipe them with sanitizer wipes. 
  • Clean your upholstery – wash using an upholstery shampoo and let your interior sit in a warm area with all windows down to evaporate moisture. 
  • Mop your mats – even if you don’t see dirt build-ups, regularly cleaning your floor mats avoids the nasty spread of germs brought from outside the vehicle through your shoes.

Photos courtesy of

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