Gas Gauge/Miles Remaining(Range)/Tank Refill not in sync?

Hi,

New owner and new to forum. Already saw this topic thread via search, but no real answer or solution...

Just bought my '20 Venture on 12/23 (Merry Christmas to me!) and it came with a full tank of gas. Dealer said "Give us 5 stars on the survey, and come back for another tank full". Ok, deal, as I would've given them 5 stars anyway.

I ran it down to under 10 miles remaining, such that the display went to ---

When I went to the gas station with the dealer guy to fill it up, it only took 19 gallons....?

I can't believe it's got a 4 gallon reserve, and the specs say 23 gallon tank with up to 490 mile range. After fill up, range went to 375.

What gives? Any thoughts, ideas, solutions are much appreciated.

TIA

~Francis

 

Miles remaining isn't the best thing to use. I don't think I've even gotten 490 to show up ever even right after filling up.

 

I also have never seen no more than 325 after a fill up. I’m averaging 16-17mpgs with mixed HWY & city.

I don’t do any hypermile driving techniques either. It’s just not realistic everyday driving that I do.

 

It's a given that EPA mileage estimates are just that, an estimate.
The/our real world mileage will always be lower.
I toggle my "DISP" button to anything but mileage numbers and mostly keep it on the MPH.

 

Thanks All for the replies.

But have you ever been able to put more than 19 gallons in it?

Like mine was "dead empty" and only took 19 gallons, and not 23.

 

They give you some breathing room on that estimate. I just filled up after going 415 miles, avg of about 20 mpg. Got like 20.4 or something gallons in. After fill up the monitor said 375-385 est range. Also I was on 1 mile of estimated range for like 10-15 miles. Only reason I did that was I knew from previous experience that there is an added cushion. Same thing in my wifes Highlander.

 

Here for the obligatory:
https://m.youtube.com/watch?v=tDnAzGpxR4k

“OH IT BROKE OFF BABY!”

 

I've checked mine once while dragging a 4,000lb. cargo trailer from CA. to MT.
Dash nanny reads 15.9, actual mi. was 11.8, in mostly 4th gear and on some grades 3rd.
5th/OD is a waste of pedal effort because it's always on the hunt for lower gears.
Hey Toyota, how about offering an axle ratio choice like you used to in the 90's.
If I keep this truck long term, I'd regear to 4.56~4.88.

 

Sounds right ..roughly 3-5 Gal in reserves so you don't burn out the fuel pump.

 

In my experience, when it says 0 miles to empty, it usually takes 19-19.5 gallons.

I've gotten 350+ miles on a tank a few times.

I try not to go more than 10-20 miles after it says 0 miles to empty. Normally I'll fill up before then, but if I'm traveling, and don't need to use the bathroom, I'll push it as far as I can.

 

4 gallons? I can believe it. The Tundra has like 8 gallons reserves.

 

I wondered the same thing on my new venture until I realized it had a big reserve.

 

I think you've answered your own questions, or at least the responses here are correct, but here's a quick recap.

1) Capacity is 23 gal
2) Light comes on before you reach "0", but it tells you have have "0 miles remaining"
3) This is on purpose, both for (a) human engineering and (b) automotive engineering; humans are bad at making good decisions about matters such as refueling, safety, and redundancy, so lying to them is useful; the fuel pump in the fuel tank is cooled by the fuel itself and may overheat when fuel levels are low

 

Another reason for the conservative estimate is that the estimate is based on the MPG you have gotten so far on the tank. If you think you’re running on fumes because that’s what the nanny display says, then you get stuck in traffic, or a detour takes you farther out of your way than expected, or the gas station you were planning on filling up at is closed or out of gas, you can wring a few more miles out of it. Personally, I would rather have the gauging error on the conservative side than be accurate or liberal with its estimate so I have a better chance of not being doing an unscheduled overnighter in my truck somewhere out in the middle of nowhere.

 

My truck has only 600 miles on it so maybe this is not representative, but here's my experience so far with the Miles Remaining and MPG estimates:

My first fill up: Truck had come new with a full tank of gas, as is normal. Filled it up when the gauge said about 1/3 of a tank left. Didn't notice the Miles Remaining but the computer said I'd averaged 15.9 MPG. However, my MPG calculation at the pump was 16.6. This seemed odd cause I've had cars with very optimistic computers (my Subaru always claimed to get about 1.4 MPG better than I'd calculate at the pump) and cars with very accurate computers (my BMW). But I've never had a car with a pessimistic computer.

Second fill up: Low fuel warning light came on when the computer said I had 25 Miles Remaining. That was at about 300 miles since the prior fill up. I stopped for gas when the Miles Remaining read 7. The tank tool 20.25 gallons. Computer said I'd averaged 16.2 MPG. My calculation at the pump was 16.1. So dead on.

So, my preliminary conclusion is that the low fuel light comes on when the computer reaches 25 miles remaining, and at that point there's actually about 3 gallons left in the tank. And when you hit zero miles remaining there's probably going to be roughly 2 gallons remaining. Also, the truck's MPG computer isn't a big fat liar.

 

A bit different than the aircraft world, where the only place the gauge needs to be accurate is on the E. For obvious reasons.

 

UPDATE: Just did a road trip, about 600 miles total. Gassed up after about 340 miles. Computer said 19.3 MPG Since Refuel and 56 Miles Remaining. My calculation at the pump was 19.6. Tank took only 17.36 gallons. And that's after I topped it off.

On return trip the computer said 20.2 MPG since refuel. The Miles Remaining plus miles I'd traveled indicated a range of just over 400 miles. I haven't refilled this tank yet.

This is on a 2020 Limited, stock, with third row seats. Only about 600 miles on the ODO at start of the trip, so not broken in. Trip had two adults and maybe 100 pounds of luggage on board. The trip up (19.3 MPG indicated, 19.6 according to my calculation at the pump) had some bad traffic jams where we were stopped or crawling for several miles, plus those 340 miles included about 50 city miles. Also, I avoided driving at a constant speed due to the truck still being in the break-in period. Also, about 2/3rds of the trip was hilly and curvy, 1/3 flat and straight.

The trip back had no traffic problems. However, I hit some high speeds numerous times and often cruised in the 70s with dynamic cruise control (which worked great, but did result in more downshifts when going up hills and bigger swings in speed than if I'd been controlling the throttle).

Both trips had AC blasting the whole way, since it was in the 90s.

CONCLUSIONS:

1. So far, the computer's MPG estimates are reliable, not lying to you to try to make you feel better about the MPG. If anything they may be a hair pessimistic.
2. Tank should usually have 2-plus gallons left when the Miles Remaining says 0.
3. 20 MPG is realistic for real world highway trips with varying conditions and pretty high speeds. I can see getting 22 or so under favorable conditions (eg mostly flat roads, a lot of constant speed and traveling closer to the speed limit).

Note that Car and Driver reported 22 MPG on their standard highway MPG test of a 2019 TRD Off Road Premium. That test involves a 200 mile loop at steady 75 MPH. Wonder how much it helped that the TRD OF would have been in RWD. The Limited of course is 4WD all the time.

PS -- I should correct my original post where I reported that the computer said I got 15.9 MPG but I calculated 16.6 at the pump. I realized I was looking at the Since Reset MPG estimate, and I misunderstood how it works. I thought it meant since resetting the trip meter. No, it means since resetting it in the instrument cluster from the steering wheel control. So I figure that's why it differed so much from my calc at the pump.

 

Highest I've seen mine is 430 miles. I average about 385 in the summer, 350 in the winter. The range seems to update every tank whereas the MPG average takes a while to update.

 

Update: Just filled up the tank from the return trip described above. By the time I got to the gas station the computer said 20 MPG Since Refuel. My calculation at the pump was 20.2. So this is another example of the computer being accurate or a maybe a tad pessimistic.

 

Hey everyone!
I have a '21 Venture and my gas mileage range barely gets to 300. My 2014 range was around 368 miles. I feel like I'm always needing to get gas. So irritating.
I know people are saying not to look at the range remaining but it's hard not to when I feel like the tank isn't the same as the 2014.

Anyone else have that issue? I see people are showing 325. Any ideas why would the 2014 show 368 and the 2021 barely get to 300? I'm thinking maybe I need to take it to the dealership.

 

My 2021 Venture doesn't go higher than 300 miles remaining on a topped off full tank.
Whereas
My former 2014 SR5 Premium showed at least 368 miles remaining at fill up.

Does anyone think I need to take it Toyota and get it checked?

 

How long have you had it? And, what are you getting for fuel economy?

The estimated range will adjust as you put more miles on it.

Also, if it's still pretty new, your fuel economy will probably improve a bit. I'm not sure if it's break-in related, or the ECU adapting to your driving, but they seem to improve gradually over the first few thousand miles.

 

Take off that roof basket. It's like a sail up there robbing you of MPG's.

 

Except for the color, I have the same 4R as you, and after a gas fill my range shows as 365 miles. I don't know what that means compared to yours.

I have no mods that might affect gas mileage.

 

Thank for the reply.
I only have around 3k miles so far. I get an average 15.8 MPG.
Maybe it's just not broken in yet.

 

After a full fill up for mine, the range is only about 300, not 365.
My 2014 got around 365 as well.

I don't have any mods that would affect gas mileage. It's just a vinyl wrap so I can't see how that would affect anything.

 

As far as I can tell the range is calculated based on your display average MPG. And a tank of 20 gallons, the other 3 being reserve.
So if your MPG since the last time you reset it is 15MPG your Range is displayed as 300 (i.e.; 20x15).

 

Hmm, interesting, thanks. I filled up and drove to LAX and got 18mpg but the tank still said 300 range.

When I bring it in for the 5k service, I'll just have them check it out for me.