As temperatures increases way above 40 degrees, so does the air intake temperature, partly because of the ambient air and partly because of the significant increase in engine temperature – the air intake is typically very close to the engine in the engine compartment
When air temperature increases, the level of oxygen in the same amount of air decreaseswhich means that your car needs more air to get the same amount of oxygen for burning the fuel (a 10 % decrease in air intake temperature will allow the engine to take in 3.3 % more fuel and hence directly increase engine performance – and if you add 3.3 % performance increase to a 300 HP engine, you’ll have 310 HP)
Image from an OBDII device showing just some of the parameters that can be read
How do you know the air intake temperature?
Many – if not most – cars have a sensor in the air intake that measures the temperature, but this information is not readily available in the dashboard – installing a OBDII device like Dashlink from Autometer (https://www.jegs.com/i/Auto-Meter/105/6035/10002/-1) should do the trick and provide you with a plethora of information about the vital life support systems for your car
What to do?
While it’s difficult to change the summer weather, there are some things you can do to decrease the air intake temperature:
- Install a snorkel. Snorkels are commonly associated with driving in and through water, but snorkels also remove the air intake from the very hot engine compartment to the outside of your car, away from the engine, which reduces the temperature of the air
- Get a ‘cold intake’ filter. There are many manufacturers that offers custom air intake filters which promises to reduce the air temperature and allow for more air (oxygen) to be pulled into the engine – this will also help reducing the air intake temperature
Frederik