Bad battery affected gas mileage

Today my stock battery on my 2018 4.6 liter just failed completely at a drive through window after 4 years and 40k miles. No warning, it just quit. Now that I’ve replaced it, my gas mileage has increased dramatically. I was getting barely 14 mpg and now it has jumped to closer to 20 mpg. I’ll repost if it turns out to be just a new battery reset glitch, but I hope it’s for real. Has anyone else experienced this? Thx.

 

It’s most definitely a battery reset glitch…..just preparing you for the inevitable disappointment

 

Dream killa

 

These damn ev vehicles

 

I have a 4.6 and I have had several batterys and my fuel mileage never changed.

 

The MPG info you see in your display is data stored in the instrument cluster. When the battery is fully removed the cluster forgets all the previous data and resets. As your drive it will relearn the fuel usage and the number will come back down to where it was. Give it a tank or two to normalize back.

A good battery is critical to keeping your electrical system operating however a good strong electrical system does not translate to less fuel burned to power the truck.

It’s still using the same amount of fuel it used to it’s just doesn’t know that yet to display it to you correctly.

 

Same thing happened to my 5.7L

 

Same thing happened to my 2018 yesterday. I walked outside after work and it was dead. Nothing there, completely gone. What surprised me was that there was no indication of it failing. Anyhow, picked up a Duralast from AutoZone on the way home. My mileage gauge went up too, from 534 to 580. Like to think it'll last but not expecting it.

 

It's your computer recalibrating after a new battery... it will go back to "normal" after a couple tanks... but if you were hand calculating your fuel use and not making judgements with your dash suggestions, you may have a happy thing going on...

 

I love how when the tundra decides it's done with a battery it just takes a shit and gives zero warning lol I lost one at my sons baseball game , exhibited zero warning signs then craoped out and wouldn't even click nor would it jump start lol love these trucks but damn come on lol