Why do trucks monitor barometric pressure?

Yes it is. Not so much at or around sea level but in higher altitudes it takes more fuel to make the same power because of the lower amount of oxygen in the air.

It's can also be used to check other pressure sensors on the engine for accuracy.

 

Oh yes indeed.

Get up into Eisenhower at about 11800 feet or so. She knows what adjustments to make to boost horsies up and over out of Steamboat.

 

How much are we talking? Typically the engine will be looking for changes in the pressure during operation. What truck and where are you reading the pressure being displayed? If the engine sees an issue with the sensor far enough out of range it will likely log a fault code, so no I would not be worried. Depending on the engine it may even be a calculated value from other components.

 

Not necessarily. If I took off after setting Baro at Searcy Airport and went into say... Little Rock General Aviation, the pressure there on take off will be different. Because the atmosphere is slightly different there. To a plane if your Baro pressure setting is correct as provided to you by Approach as a check to your landing runway's altitude your plane will know where it is and how high.

Trucks try to keep that stuff away from Flipflop Diploma Holders who lick windows in a attempt to escape their gilded cages.

 

With that engine the difference in pressure readings is the least of your problems.......