2024 Toyota Grand Highlander Fuel System Problems

I am submitting this complaint regarding a catalytic converter failure on my vehicle and the manufacturer’s refusal to honor the warranty. My vehicle is a Toyota that is approximately two years old and currently has about 31,000 miles. The catalytic converter has failed well before what would normally be expected for this component. When I brought the vehicle to the dealership for repair under warranty, Toyota declined to cover the repair. They stated the failure was due to “contaminated fuel,” but they did not provide any evidence or test results showing that contaminated fuel was present in the vehicle. I have not been provided with documentation, diagnostic data, or fuel analysis supporting this claim. The denial appears to be based on assumption rather than proof. Because catalytic converters are emissions components that are typically expected to last much longer and are often covered by extended emissions warranties, I am concerned this may represent a broader issue affecting consumers. Vehicle details and service documentation can be provided upon request. I am requesting that this matter be reviewed and that the manufacturer be required to provide evidence supporting their claim or honor the warranty repair. Thank you for your time and consideration.

Numerous times now the vehicle will not accelerate from a stop for about five seconds after the gas is pressed. It always seems to be on hot days with high air conditioner demand.

After driving over 15k miles in approximately one year, my 2024 Toyota Grand Highlander Hybrid fuel tank has never been filled with more than 12 gallons of gas, even when the Low Fuel light is on and the miles to empty are less than 10. The MPG for individual trips can be as low as 10.3 MPG; the overall average MPG has been 21 MPG or less. The advertised fuel tank size is 17 gallons and the MPG is 26/27. The Toyota dealership said that there are 3-5 gallons remaining in the tank when there are as few as 5 miles to empty. Actual miles to a tank are around 280-300 when driven in Eco mode; advertised is 450 miles when driven normally. Inaccurate fuel level sensing is a safety issue. 10.3 MPG for a Hybrid that is advertised to get 27 MPG is false advertising. This is a known issue since at least November 2023, as evidenced by the Manufacturer Communication Tech Tip T-TT-0742-23 on NHTSA.GOV.

This vehicle is supposed to have a 17.8 gallon tank but each time at fill up when the vehicle is on empty you can only put about 13.5 to 14 gallon of gas in the tank. Several owners are experiencing the same issues. Toyota Dealerships are aware and no action is being taken to resolve this issue. The mileage to empty is not aligning with the amount per gallon as advertised per TOYOTA manufacturer.

The contact owns a 2024 Toyota Grand Highlander. The contact was unable to fill the fuel tank completely. The contact stated that the fuel tank had a 17-gallon capacity; however, the contact was only able to get more than 10 gallons into the tank. Additionally, the contact stated that the Auto START/STOP feature was not functioning as needed. The contact had taken the vehicle to a local dealer, who was unable to determine the cause of the failure. The vehicle was not repaired. The manufacturer was not informed of the failure. The failure mileage was 16,455.

Vehicle does fill gas tank to capacity of 17.2 gallons. It only fills about 12 gallons. It has a 2.6 gallon reserve so only fills about 14.5-15 gallons. The reserve is not included in range est on dash. Vehicle gets 230-270 miles per tank. You have to pull gas nozzle half way out to even get this 12.9 gallons - gas almost overflows to get this done. If your est millage left is 44 miles you can only get about 10 gallons in. The gas overflowing when trying to get more gas in the car is common. Many complaints online. This is a safety issue and known by Toyota and dealerships.

Since purchasing this vehicle when I have driven the vehicle and come home the vehicle smells of gas vapor/fumes. It's so bad the entire garage will fill with the vapor. Im afraid the garage will explode. I have to leave the vehicle parked outside for several hours until the smell is gone. This is a known issue for this car as others have complained about the same thing. Dealership has confirmed it is a known problem. They tried o tell me the first time I took it in that it was due to extreme heat in Las Vegas. I explained that our other vehicle and our friends vehicles don't do this and that is merely an excuse. After researching online I found that several other others in other states have the dame issue. When I recently took the vehicle in for software/radio issue as well as the gas vapor they did confirm it is a known issue. This is a safety issue as it could cause an explosion in small spaces where parked. We have an air conditioner for our garage but even at that it's extremely dangerous. This has happened on several occasions. Most recent is listed below.

I have a 2024 Grand Highlander and when I get to empty the most I can put in it is 10 1/2 gallons of gas. Toyota said I had a 17.2 gallon gas tank. I’ve called Toyota. They set up a appointment. They were going to pull the gas tank and check the sensor. The dealership said oh no you have a 5 gallon plus reserve in that we have the same problem with the RAV4, the problem is because on trips you have to keep stopping for gas when I get 325 to 340 miles it tells me I’m empty when I fill up it says I can go 520 to 540 miles the most I’ve ever been able to put in it was 12 gallons and that was going down beyond empty and driving it for another 50 miles. It doesn’t make sense to have 5 gallons 6 gallons 7 gallons of gas sitting in my truck that I’m carrying that weight and not getting to use it this just doesn’t seem like Toyota‘s way of fixing things. I did recall Toyota and now they tell me I have to get the dealership to do something about it. They don’t do repairs on their vehicles. Only the dealership can do that.

I live in Arizona and the car has bad gas smell after drive a while(usually between 10-30 minutes) in a hot day (usually afternoon). I took the car to dealership and they replicated the issue and the dealership said Toyota told them it’s due to excessive heat and told us to use better quality gas which we are already getting gas from Chevron and Costco. Seems this is known problem because I saw other grand Highlander owners complained the same issue but Toyota is not doing anything to fix it. They can’t blame on the heat since they are selling the vehicles in AZ/NV. After drive the vehicle during a hot day, park the car in garage and the garage smells like gasoline.

Fuel tank is 17.2 gallons. Refueling on empty only can put in max at 12 gallons when fueling tank is full or stopped. Have never been able to put more than 13 gallons in this tank. Has taken the car to dealer for checking, they came back and said the tank was a 17 gallon tank.

The fuel tank capacity according to the vehicle specifications should be 17gallons. I have refilled the vehicle three times after reaching empty (around 20mi left according to the gauge), and when I fill the tank it only takes about 11 gallons to fill. That is a significant difference. Even with a reserve, I should be putting around 15 gallons in the tank when it is on empty to fill it. I am concerned that the tank is not the correct size or there is a problem with the fuel level sensor.

Since we purchased the 2024 Grand Highlander Hybrid Limited in April 2024, there has been an issue filling the fuel tank completely when the vehicle is on empty. The stated fuel tank capacity from the owner’s manual is 17.8 gal, however the maximum amount of fuel that can be pumped into the tank using auto fill at the gas station is 12 gal before the pump “kicks off”. After this, the fuel gauge on the dash reads full, however fuel range shown is 330 mi (at 30 mpg average gas mileage) when it should be closer to 500 mi with specified fuel tank capacity of 17 gal and 30 mpg. Shortly after filling the fuel tank, the fuel gauge and range will quickly decrease while driving. From researching and reading dozens of online forums about this issue, I tested filling the tank manually at the pump, extremely slowly, not using the auto fill lever. Two times doing this test, I was able to pump 14.5 gal into the tank before the pump “kicked off”. After these fill ups, the fuel gauge showed full and did not quickly decrease when driving. Also, the range now showed 450+ mi remaining. Both times after what appears to be an actual full tank fill up, the vehicle recorded over 400 miles before the fuel low light turned on, while previous max miles was in 300 range. It seems as if the fuel tank design does not allow the fuel to enter and settle in the tank quickly enough when filling, causing the pump to “kick off” prematurely and not actually fill up the tank. This issue causes the vehicle to not reach the full mileage range with advertised MPG and tank capacity, causing more frequent and inconvenient trips to the gas station. We have taken the vehicle to a Toyota Service center and they documented the issue but were told by Toyota Corporate that they do not have a fix for it at this time. Tech Tip T-TT-0742-23 exists on NHTSA.GOV website related to this issue from November 2023.

Toyota is having issues filling up the tank as the specs says (Owners manual book). According to the Owners manual book, the Gas tank of these vehicles are 17.2 Gallons and 2.6 of those are saved for the reserved. In theory, we should have 14.6 Gallons to fill-up as soon as we see the "Empty sign" on the vehicles. Now, the thing is that even after this happens, we can only fill-out up to 11.5 gallons. I have tried several times, saving the history on FUELLY, and its always the same. I have asked the dealership and they don't know what to do. If you just search for "Grand highlander gas tank issues" you will find thousands of people that have the Grand Highlander (not only the Hybrid, models, but all models) are saying the same thing (Facebook groups you can join and talk with real people who can prove you this issue) the gas tank cannot be filled up to what the size of the tank is (owners manual) This is not good since we dont know the real value of miles / gallons of tank left so we know when we could fill up the tank specially if you are on a long road trip where there are not a lot of gas stations between places. Please ask TOYOTA to find where the issue is in here, it might be just the air is not allowing the gas pumps to fill out more gas in the tank.

Myself and all Grand Highlander owners of the new version that just came out in 2024, we have the same fuel issue. The car is only registering half a tank of gas. If you go to the grand Highlander forum every driver is reporting the exact same issue over the last three months that the car has been out Toyota has put out a statement but has no solution, it is a hybrid and it’s supposed to get 400 miles or more per tank and we have to fill it up every time we drive only 170 miles. However, when the tank says on the digital screen that it is empty, there is still 10 gallons in the tank. This is for all owners and effects all cars of the Grand Highlander Platinum Max only.

Published 2024 Toyota Hybrid Grand Highlander (TGH) specifications, the TGH owners manual and dealer information provided indicated the vehicle has a 17.2 gallon fuel tank. However, the most fuel I am able to get in the tank is between 11 and 11.5 gallons. I've had the vehicle in to fix the defect on three occasions; 2023-11-27, 2024-3-11, & 2024-8-13 to no avail. On the second service, Toyota's technician said the tank had 16.8 gallons remaining when I picked it up, I had filled it the previous day and driven approximately 15 miles. Once the gauge showed near empty with only a few miles left of fuel, I filled the tank and was only able to get 11.4 gallons in the tank. There appears to be six gallons of fuel that I am carrying in the tank that the fuel system cannot access. I have searched on-line and found that a number of other TGH owners are experiencing a similar defect.