[CC_HH]

My 2021 is at the dealer getting the tank replaced this week, going on 3 days.

I predict you'll be as disappointed as @gritbob .

Toyota just needs to change the fuel tank capacity to 15.x in the manual, because that's what it practically is.

Congratulations on replacing a perfectly good gas tank with another one that's exactly the same.

 

[CC_HH]

There's no winning for any car manufacturer. If they actually diid what you suggested, there'd be drivers who would actually take it to the limit. It's a safety margin to account for possibly of becoming stranded and it mitigates any chance of damage that can result by driving it to empty.

No one here is making an excuse for Toyota. This is a design choice that makes sense to me but not others. Obviously, you can't please everyone.

One of the most important purposes is so morons don't burn out their fuel pump. The pump needs a minimal level of gas to be present and "bathe" in so it stays cool. If morons ran their tank to "E" after every fill up, they'd be replacing fuel pumps once a year. The physics of it with current tech are hard to avoid.

So in other words, don't be a moron - which is probably too much to ask of some folks these days.

And to add - this just might be the dumbest argument I've read on a vehicle forum in a long time. Second only to "auto-stop/start is killing my starter!"

 

[CC_HH]

Not a dumb argument at all. The problem is that Toyota has failed to comply with established norms and as a result has produced a gas gauge that is unreliable. With EVERY OTHER MANUFACTURER, empty means empty. So most people know to start looking for gas when the gauge gets below 1/4. When the Low Fuel light or warning comes on, you get gas ASAP. In the Highlander, that's more of a suggestion. So now that my wife (it's her car) knows that there's a secret reserve, she drives it until it reads "0." So what happens when she drives my car, where 0 is really 0?

THAT'S NOT TRUE AT ALL (I can also type in all caps to make myself sound more authoritative, but in this case I can present evidence). Every other modern vehicle I've owned (since the dawn of fuel injection) has had a reserve of ~2 gallons after dte=0 or E. Subaru, Ford, Jeep, you name it. It's what I'd call "common knowledge," but like common sense I guess it ain't all that common.

fuel warning accuracy

Today I filled up when the warning said that I had 26 miles to empty & I've been getting 19.7 mpg. It took 16.8 gals. so that says to me I have a SLIGHT bit of leeway with the miles to empty. Al

www.ranger5g.com

On empty, how many more miles?

I’m sure it’s been asked and answered but taking too long to find it. What’s the mileage we get once the gauge shows empty?

www.jeepgladiatorforum.com

How Far Can a Subaru Forester Go On Empty?

How Far Can a Subaru Forester Go On Empty? In general, you can drive Subaru Forster for around 34 to 38 miles with an empty tank. It has a tank capacity of 16 to 18 US gallons. Also, the fuel light illuminates when the tank has 2.4 to 2.7 US gallons of fuel left.

trucksauthority.com

How much fuel left in tank when 'empty'

I bought a used Suburban, with the 42 gallon tank, and leaky fuel lines. Fuel hardlines were well rusted, so I decided to replace all the lines. I'm replacing the fuel pump and sending unit, since it's the original with 142k miles on it, and I've got the tank pulled anyway. I disconnected at the...

www.silveradosierra.com

Cry somewhere else.

 

[CC_HH]

For my issue, I just explained that the tank always clicks off at 3/4 and that usally puts me around 380-400 miles to empty. Since I live in NJ, we don't pump our own gas often, but this past weekend, it was pretty apparent when we were in Vermont visiting family, and I could manually force pump another almost 4 gallons into the tank after first click and finally got it over the F line to the point I could see the fuel in the top of the tank. That's not normal.

The tech didn't even bother testing anything. They took me for my word. I am satisfied. The tank will arrive Tuesday, and get into the shop Wednesday.

Thank your stars, from the sounds of it the supply chain problems has slowed down almost everything. If you have your car back by the weekend it'll be a miracle.

 

[CC_HH]

So this would mean even though the refuel message was on I still had 3 gallons of fuel still left in the tank being that its capacity is 17.1 gallons.

Let me get this straight - they replaced your tank and you think they took all the gas out of the old one and put it back in the new one? Do I have that right? 🙄

 

[CC_HH]

Mods (@John Anthony, etc), if you want to roll this into the merged thread, that's fine, but I thought this might deserve its own thread because I have some anecdotal insight and I thought people who are having issues might want to help prove/disprove what I'm seeing.

The merged thread.

After a wide range of driving conditions this past year, I believe this is (mostly) a software issue. I think what we can all agree on is there's some learning ability in the gas gauge/DTE software - where it's taking into account your recent mpgs (past two tank average is what I've "read") to calculate your DTE. I think there's also some factoring there for gauge "fullness", but am not entirely sure.

Anyway, what I've noticed over the past few months is that as I allow the tank to get closer and closer to empty before filling it (searching for the lowest gas prices mainly), the higher my DTE has gone, and the more I've been able to add to the tank when I get closer to empty. These past two tanks especially, I've gotten it down to ~5 miles to empty and found my DTE jumping 5-10% over what I would have expected, and getting very close to the 600 mile mark (after hovering around 500 for most of the year). I've also noticed it's taking slightly more than I'd expect to fill it, more than 15 gallons vs. 12-13 when I've only let it get down to 25 miles to empty. That doesn't make sense when I'm getting 35-40mpg; 25 DTE would translate to 2/3rd a gallon, not 2+ whole gallons.

I think this is because the software needs to see those near-empty readings to "learn" what an empty tank is supposed to read. If you're filling up at a quarter tank every time, it may never learn.

On the flip side, it may have to learn what a full tank looks like, too, so it's important to both fill completely and drive down close to E for it to register. I've seen the gauge not reading full, despite filling it, just once - this summer when I was towing a trailer across the Midwest, not knowing where the next station would be and filling up every 200 miles or so instead of when nearing E.

My advice (@reezick, @kalagher @dtime1 ,etc) - if you're having trouble getting the gauge to read full, or you're upset your tank won't take more than 13-14 gallons when "empty" - try this: for the next 3-4 tanks, fill completely and drive down as close to DTE=0 as you're comfortable doing - sub 10, if you can. Help teach the software what a full/empty tank looks like and you might start seeing improvements.

I know there's a couple on here who've gotten replacement tanks/pumps/sending unit/gauge, etc and have seen improvements. That doesn't necessarily negate the theory.

 

[CC_HH]

I took the TSB into my dealership yesterday when I had my 20k service done. The 2 people working the service desk played dumb (or genuinely didn't know about it). They acknowledged similar problems with RAV4's but not Highlanders. They did agree to me setting up a follow up appointment in 2 weeks to look into it. I have to bring it in nearly empty of fuel and they will fill it up to see what happens. One of them told me that 14.9 gallons is considered a "fill up". He was reading something from his computer screen when he said this. I've never got more than 13 gallons in it. And that was putting in fuel after it automatically clicks off. I usually get in 10.5-11.5 gallons at the initial click off, even with the "low fuel" light being on.

I genuinely want people to try something - drive it down as close to E as you can, DTE=0 if possible, and keep doing that for several tanks. For the first year of ownership, I wasn't putting more than 13 gallons in, despite DTE getting to ~20-30 miles. Looking back at my data, anywhere between 11.5 and 13 gallons for the first 15-20 tanks. Over the past several months, for one reason or another I'd be getting very close to DTE=0 (looking for cheap gas stations, mostly) and I noticed that gradually, both my estimated DTE and the amount of fuel I was putting in would go up. The last 5 tanks, I've been putting in closer to 14-15 gallons when getting down to DTE = 20; one in September was 15.25 gallons.

I fully believe this is a software issue with the DTE estimates from the ECM/PCM not being aware of what an empty tank reading looks like. Could be something as stupid as having inconsistent or varying volume of fuel in the tank when the car is first started when leaving the factory.