Greasing the Zerks

Question: I bought a certified used 2015 TRD Sport from a dealer back in September. It had roughly 33,000 miles on it. I noticed when I bought the truck, the listed fuel economy was slightly lower than expected. I just tested the mpg the last time I filled up and was shocked to see I'm only getting about 13.5 mpg...I was reading about greasing the zerk fittings after 30k, and how that could possibly boost your fuel economy, however, I'm wondering if it is necessary or if they would have done that already at the dealership? Like is it considered standard maintenance for a truck over 30k or would I have had to especially ask them to get it down before buying? I just don't want to invest the time or money if it was just done 5k miles ago.

 

In theory less friction equals less energy needed to move something so if your zerks are greesed every couple of oil changes the drive shaft will spin easier in essence requiring less energy to spin. MPG can be from lots of things from the fuel, tires, driver, terrain, etc.

 

Yeah, regardless of whether or not it'll help the mpg, it's something I want to add to my general maintenance. That being said, I'm just wondering if it is something the dealership would have done when they processed it and were getting it ready to sell since they got it when it was just over 30k miles. I just did my first 5k oil change over the weekend.