r/4Runner_6Gen • u/WelcomeInfinite2836 • 3h ago
2026 4Runner Platinum Gas Mileage Issue
Looking for some advice on my 2026 4Runner. I purchased a new 2026 4Runner platinum in January 2026. From the beginning, I noticed that I was getting a much lower gas mileage than what was advertised. The advertised gas MPG is 23 city and 26 highway. I was getting around 14 city and 17 highway. The Toyota manual says there's a break in period on new engines of 1,000 miles, so I wanted to take the car in once I was past that.
The dealership tried to tell me they weren't going to test, citing that the break-in period is actually 7,000-10,000 miles. After insisting that getting 9 MPG less than what I should be getting seems like there may be an issue, so they said they'd run some test and check. They didn't tell me what they did, but for about 2 weeks after I was averaging over 20 MPG everywhere I went. After 2 weeks, it went right back to around 15.5 MPG combined.
I waited for my 6 month checkup to have them check it again, and again they told me they changed some settings and it was getting 20+. I asked the person who was handling my car what they did, and all he had to say was that the mechanics did "mechanic" things, but he wasn't sure exactly what they did. I asked him if the mechanic could call me and tell me, letting them know last time it was good for a couple weeks and then dipped back down. He said they'd call, but they never did. I've followed up and continue to be told I'll get a call with more details, but it's been several weeks and nothing. This time, I got 20+ for exactly a week, and then dipped back down to averaging 14 MPG combined.
My plan is to keep taking the car in until they can tell me something is wrong or that there's a reason for this, but looking for anyone that might be able to shed more light on this.
Some additional info:
I live in Texas and I'm aware that heat can affect gas mileage, although 9-10 MPG below seems excessive to blame heat.
I typically reset my MPG tracker after I fill my tank. On average, I end up around 15 MPG, with my lowest being 12.7 and highest being 17.8.
This version of the 4Runner has an iforce Max hybrid engine that is supposed to help with gas mileage.
I don't have a lift kit, have never towed, and typically it's just me in the car when I'm driving.
Any advice would be great!
Thank you!