Scientists discover that the inside of your car is actually dirtier than a toilet

Scientists have revealed that the inside of your car is dirtier than the average toilet, highlighting the problem areas where harmful bacteria can thrive.

The startling results may make you think twice next time you get behind the wheel - especially when it comes to keeping food in the car.

Researchers at Aston University's School of Biosciences took samples from car interiors with varied ownership histories, to establish bacterial contamination levels within the vehicles, and to highlight just how thoroughly people actually tend to clean their cars.

One area of our cars rated significantly higher than all others, recording more than two times the amount of bacteria as the next most grubby.

All six of the problem areas were found to contain more bacteria than a toilet seat, but it was the car boot that really came up short.

It was found to have a massive amount of harmful bacteria, including E.coli - commonly found in faeces.

Something to think about next time you throw your shopping in the boot.

Four-wheel grime: The dirtiest parts of your car

• Boot - 1425 bacteria identified

• Driver's seat - 649 bacteria identified

• Gearstick - 407 bacteria identified

• Back seat - 323 bacteria identified

• Dashboard - 317 bacteria identified

• Steering wheel - 146 bacteria identified

• For comparison, only 34 bacteria were identified on a toilet seat.

Researchers found a correlation between the age of a car, and the levels of bacteria likely to be found within it. The older cars sampled for the study exhibited higher bacteria loads than those that have been on the road for a shorter amount of time.

However, the study did highlight some good news for drivers, as the researchers found that out of all areas within our cars, the steering wheel is generally the cleanest. This high-contact area saw very low levels of bacterial contamination, which is potentially thanks to the uplift in hand sanitiser use following the Covid-19 pandemic.

Dr Jonathan Cox, Senior Lecturer in Microbiology at Aston University commented: "The results of this study are fascinating, as they help to show that despite cleaning our cars, the older they are, the dirtier they generally are.

"These results however highlight that we should instead change how we think about our cars and cleanliness. Often, we will clean our cars based on whether they "look" clean versus whether they actually are clean, but you would never even think about eating off of your toilet seat. Upholstery, in particular, should be given deep clean and I for one, will always clean any used car I buy in the future myself!"

This article was first published by the NZ Herald and is republished here with permission.