2020 Toyota Tacoma TRD off road Hiway Gas Mileage issues?

Thats the same issue I have, the dealer told me to set the cruise control up a few mph, and it will shift back. but I found the same trick to manually downshift, put back to drive is faster. It will always kick it our of the lower gear to the higher gear where it is supposed to be. The dealer also said, you have never driven anything like this before. Thanks, why didn't you tell me that Before I bought it. I don't know how this can be so highly rated as a truck its a piece of junk to drive on the freeway or a long trip. I just dont know if this truck is a lemon, or if they all are like this?

 

I want to reopen this thread to bring up my issue, very related to this one.

Suddenly on 11/26/22 after filling up the tank with the usual 87 octane fuel on a road trip home from Thanksgiving, our "Estimated Miles to Empty" calculation was ~260 miles. We bought this truck brand new and on every tank before this day we have seen a calculation of ~320 miles per tank CONSISTENTLY. Why would this number suddenly drop so significantly? Concerned something was very wrong, we stopped at a dealer en route who ran a diagnostic on the systems but didn't result in any errors or issues. They had no explanation. It's almost as if they didn't hear "this drop just happened and we're not crazy because we pay attention to this stuff" and they sent us on our way. I have searched this forum and Googled it but haven't seen this exact issue explained/asked this way. Obviously, the current system-calculated MPGs have decreased as well but the number that drew our attention was the miles per tank.

This lower calculation has happened for every tank since - probably 3 tanks now.
~30K Miles
We have no engine/computer mods.
No fuel additives
Vehicle seems to be running fine, i.e., plenty of power, shifts okay (I've never liked the throttle response and shifting of this Tacoma but I mostly drive older vehicles with manual transmissions.)
We're current on our maintenance and oil changes.
We have a topper but we've had this topper since a couple months after purchase.
We are on General Grabbers in stock sizing, but we've had them way before the calculation dropped to ~260 miles.

No other changes that weren't there before the drop in "Estimated Miles to Empty" number.

Any others experience this change? Any word from a dealer on what would cause this? Any fixes?

Thanks for any feedback.

 

Exxon fuel. Lol those pics are 5mph off (cruise control setting, also taco hates that on hills If u haven’t noticed) and different temps cruise control, etc…. I’m here because seems Exxon is getting me consistently worse mileage than non-top tier, Shell or BP. Definitely keep your taco under 80 or 70 for best mpg results, that is a constant. Got stumbles when using non-corn fuels and not any more efficient…. Stinks cause I thought I had a tiger in the tank, but must be water instead.

thumbs up to anyone who said these are designed to run on ethanol blends up to 15 percent, have witnessed firsthand. These are not the best highway efficiency rigs ever, and will get worse the faster you go, just keeping up with traffic on I 75/95 will have you at 16-18 A/C on no mods… dealer always adds air even though tires on or over door jamb already, typical mpg mod lol

 

Are you using your cruise control? Or foot on pedal?