What now?

[FC]

Originally Posted by clyde

First potential issue?

Discovered on the interwebs today that there seems to be a common issue with the 2019 RAV4 Hybrid where people can't put more than 10 gallons of gas into what's supposed to be a 14.5 gallon tank no matter how low they run them down. And it seems to not be "up to 10" as much as "10 gallons goes in."

Some people say they can put in two or more gallons after the auto shut off, but get scared about overfilling. A few have had their cars in for service because of it and Toyota engineers have come in to look at the cars.

Wonder if there's a TSB or recall in the future. Or if Toyota put smaller tanks in than the specs. I asked my wife and she says "10 gallons every time."

That's interesting. Too many possibilities without knowing what the system looks like, but I love investigating stuff like that at work.

[equ]

Motorcycle tanks that stray from the teardrop design, for space, efficiency or whatever other purpose have issues. Particularly, the Ducati Multistrada and my previous BMW F650GS. Sometimes I would pause in the middle of a fill-up and rock the bike a bit to let it all settle to allow more in.

[clyde]

Originally Posted by FC

That's interesting. Too many possibilities without knowing what the system looks like, but I love investigating stuff like that at work.

Dunno if the pic will work:


Some are thinking the fill tube takes a convoluted path to the tank and combined with a narrower diameter than fill tubes in most other cars, it creates more turbulence that causes shut off. Some people say they've had luck holding the fuel nozzle at certain angles while filling.

One guy that's very vocal on the Rav4World.com forums says that Toyota techs and engineers have disassembled much of his fuel system, checked the evap system for blockages, charcoal canister, etc for issues and can't find anything wrong, but acknowledge that it's not working correctly.

Owners in Europe don't seem to be having a problem.

[ZBB]

Could it be something with the venting system (or venting recapture if your state/county uses that on the pump handles)?

I know when the venting recapture first came out (early 90s I think -- AZ had them shortly after CA) that there were a ton of problems with the auto stop clicking off way too early...

[kognito]

Originally Posted by clyde

Owners in Europe don't seem to be having a problem.

I haven't pumped gas in Germany in a while, but I seem to remember that their nozzles are smaller diameter.

FC, you fill with gas during your ED trip? Did you notice this too?

[clyde]

Originally Posted by ZBB

Could it be something with the venting system (an venting recapture if your state/county uses that on the pump handles)?

I know when the venting recapture first came out (early 90s I think -- AZ had them shortly after CA) that there were a ton of problems with the auto stop clicking off way too early...

I remember those issues in California. Most nozzles here don't have them. Even the ones that do often seem decorative in nature compared to California.

[clyde]

WOT alert

TL;DR: The RAV4 has a fucked up fueling issue that significantly reduces range on a single tank

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THE SETUP

The fueling problem on the 2019 Toyota RAV4 Hybrid is that the fuel tank that is speced at 14.5 gallons behaves as though it is about 11-12 gallons.

The megathread on rav4world.com has very little hard data and they rely on dubious refernce points like where the needle points on the fuel gage, distance to empty readings, etc, and very little "I went XYZ miles and it took A.B gallons of fuel using [pick your poison] fueling method."

A couple people have taken their cars in. Some have had their service advisors watch the owners fuel up. There is one guy that's like a dog with a bone and has taken his car in a few times and Toyota engineers have looked at the fueling system, agree it isn't working right, but told him they couldn't find anything wrong. none of the other cars that have been in for this have left with a "fix" or an aknowledgement that Toyota knows there is a problem and they are working on a fix.

Speculation runs along a few lines:

• The fuel filler tube is so narrow and bends around so much that there's too much turbulence even with a really slow gas flow and the hole in the nozzle gets covered triggering shut off
• The opening to the fuel fill tube is angled poorly and doesn't allow fuel nozzles to sit in them properly
• Something in the venting system was manufactured/installed out of spec
• Installed gas tank is smaller than it's supposed to be

A few things to note:

• Non-hybrid 2019 RAV4s don't have this problem.
• Euro market 2019 RAV4s don't have this problem.
• The North American Hybrid has some weird emmisions trickery that begins with pressing the door release button under the dash. It can take 10 seconds for the door to open and the MFD on the dash tells you when it's ready (this 10 second and message thing is new to me just having looked at the manual moments ago). When the door opens, a swtich (think fridge light) opens a valve somewhere. If the doors doesn't close, the valve closes 30 minutes later. There is a warning sticker in the fuel filler area and a paragraph in the manual stating that if you attempt to fuel more than 30 minutes after the door opened to push the dash button again to re-open the valve or you may get overflow during fueling.
• Not sure if Euro version has the same valve, vent, whatever

CLYDE'S FIRST FILL UP

Last night was the first time in almost 6,000 miles of ownership that I got to fuel up. My wife has not been keeping close track of miles per tank and gallons consumed, so I only have the OBC to work from.

The low fuel light is supposed to go on with 2.3 gallons in tank. Most people report the Distance to Empty reading is in the mid 30s-mid 40s when it lights (but never in conjunction with their MPG either displayed or actual). If I was smart, I would have waited for the light to go on before fueling, but I didn't.

OH NOES!!!!! CLYDE STARTS THINKING

The trip odometer (which my wife does reset religiously) read 399.x miles. How does that math work if assume the low fuel light would have turned on in the next couple miles?

I had already been thinking a good starting assumption would be that when DTE ran down to 0, there was probably 1.0-1.5 gallons left. Since most people report seeing DTE readings in the mid 30s to mid 40s when the light goes on and also report similar MPG (although never DTE and MPG together and rarely whether MPG is indicated or done with real math).

If I was smart, I would have waited for the light to come on before fueling, but I didn't. DTE reading was 39 miles and indicated MPG was 43.8, so I'm thinking it should have been really close.* If there was 2.5 gallons left (I'm consciously cheating towards more gas in the tank so it needs less to fill up), it should take 12 gallons to be full.

UH-OH, CLYDE MATHS

The trip odometer read 399.x miles with an indicated 43.8MPG on the tank, which would say that 9.1 gallons were used. Based on experiences with other cars, that 43.8 is probably a little optimistic, so I was guessing actual is probably closer to 41.5 MPG. My wife told me she normally fuels up a little bit after the light comes on, not immediately.She also said it always takes very, very close to 10 gallons even and that the indicated DTE after filling is usually 450ish. 450 would be consistent with an actual MPG of 41.5 and 11 gallons in the tank which would be her normal.

Based on all that, I expected that fueling the same way she does (putting nozzle in, setting the lock, and letting go) would result in the fueling to auto stop at about 9.5-9.7 gallons.

RAV4 TO CLYDE: IS IT IN YET?

When I went to fit the nozzle in, A few things jumped out at me. The opening to the filler tube moves around. A lot. I don't think I've ever seen this before. If I hadn't read about it first in that megathread, I'd probably think it was broken as opposed to "they all do that."



Another thing is that fitting the nozzle in normally does not feel secure. People on the forum also talked about the filler tube being really narrow. The mouth opening feels like it may be a lot wider than in other cars (haven't checked), so the nozzle has more room to move around. That's compounded by the motion possible in the tube itself. Further, it may be because of a wider mouth, but it feels like the nozzle doesn't go in quite far enough, or, that's a byproduct of the nozzle being at a more horizontal angle than I recall with most other cars. Whatever the reasons, leaving the nozzle in the tube mouth feels precarious. But, I let it run its course normally until the first auto shut off...which happened at 9.6 gallons.

Then, I manually held the nozzle at a slightly more vertical angle (like it should be?), held the trigger, and about 0.7 more gallons went in until the next auto shut off. I coaxed anothertenth in short bursts before I felt like I'd pressed my luck far enough. I got back in the car and the DTE read 527. (FWIW, the fuel gauge needle was past the F mark like you'd expect in most cars with a full tank). If there was 2.5 gallons left in the tank, it should have taken 12 gallons to fill, but it only took 10.4 leaving a missing 1.6 gallons.

I drove 2.3 miles down the street to the next gas station and using the manual vertical method of filling, put 0.5 gallons in before chickening out on getting more in, but it after the first two tenths, it was all in short bursts of as slow flow as I could control. So, that's 10.9 new gallons in, plus up to 2.5 that were already there, is 13.4 gallons with 1.1 gallons of space unaccounted for.

There was a bit of noise at both gas stations, so it was kind of hard to hear the fuel going in. It sounded like it was getting full earlier than it would have in other cars and that it took extra time for the noise to end after the fuel flow finished. I only have a low to medium confidence in that assessment, though.

GET READY FOR CLYDE TO DRAW CONCLUSIONS, BUT DEAL WITH HIS WISH LIST

At this point, I am inclined to believe there is an issue with the venting and/or the filler tube design and/or its assembly. The gas is backing up and taking its time getting to the tank and/or venting is not working the way it should.

I wish I had the skill to find fuel level on the CANbus.

I also kind of wish I hadn't mentioned it to my wife. Now that she knows there's an issue that is reducing her fillup interval from every 7ish days to every 5ish days, she's pissed.

EXTRA

*but maybe not that close...if the tank needs to be fully filled and run down to nearly empty every so often to calibrate and the car hasn't been fully fueled, it's not going to have the opportunity, so

Also weird with DTE was that it did not go up after adding the 0.5 gallons at the second gas station. Maybe the DTE calcuations are based on fuel usage only based on that fuel filler door valve switch activation? That can't be right becuase it has to have some idea of how much gas went in.

[Nick M3]

Has anyone actually run one to empty and then filled up?

[FC]

Originally Posted by clyde

clydes long explanation

I'm sorry I just saw this thread again since my last post. Also, wicked busy right now, so I only skimmed.

A couple of things:

1) It seems there is more variability in the amount of fuel allowed in than exactly or close to exactly 10 gallons. That opens up possibilities. I'll need to re-read and re-think.

2) I think you touched on it, but the convoluted, long, and narrow fuel tube path combined with potentially poor venting could certainly be causing premature shut-off. Maybe it doesn't burp fuel vapors well enough. The schematic is far from a detailed drawing, so hard to tell.

3) The loose tube is all sorts of F'd up, but unsure that it could be a contributing factor.

4) Don't dismiss the very real possibility of a wrong fuel tank volume compared to the published value.

[clyde]

Originally Posted by Nick M3

Has anyone actually run one to empty and then filled up?

I'm kinda tempted. You know, for science.

Originally Posted by FC

I'm sorry I just saw this thread again since my last post. Also, wicked busy right now, so I only skimmed.

A couple of things:

1) It seems there is more variability in the amount of fuel allowed in than exactly or close to exactly 10 gallons. That opens up possibilities. I'll need to re-read and re-think.

2) I think you touched on it, but the convoluted, long, and narrow fuel tube path combined with potentially poor venting could certainly be causing premature shut-off. Maybe it doesn't burp fuel vapors well enough. The schematic is far from a detailed drawing, so hard to tell.

3) The loose tube is all sorts of F'd up, but unsure that it could be a contributing factor.

4) Don't dismiss the very real possibility of a wrong fuel tank volume compared to the published value.

1) It's really hard to separate the wheat from chaff in the thread (although I might get around to it for giggles), but the impression I get is that there is consistent reporting from people that fill up as my wife does a little bit after the light goes on only being able to put in about 10.0 gallons without making an extra effort.

4)Entirely possible. Just wish I knew what size so I'd know how much gas can go in before overflowing. I'd have to go back and check, but I think the most anyone has been able to put in is 12 gallons, but dunno how empty they thought it was. I know I saw someone say they 11.5. I put in 10.9 before I chickened out about putting in more on top of the 2.5 I thought might already in there.

I'm also thinking about trying to fill it when the valve controlled by the fuel door is closed by opening the door more than 30 minutes before filling and see what happens. May not be a smart move, but I'm curious.

Like I said up the thread somewhere, cars had only been available for a week or two when I bought this one. Supplies are still limited (but growing), so there aren't that many cars in customer hands. The ones that have been purchased are probably getting normal miles put on them with really great mileage, so the average sold car probably doesn't have more than one or two fill ups yet, so most owners haven't had a lot of opportunity to notice an issue, yet. And they're Toyota owners, so, they might not ever notice.

Trying to figure out it if it's worth taking the car in with as much annoyance that would bring my wife. She's the one pissed off about getting gas more often would be my counter, but I don't think that matters.