Fuel Tank options for Land Cruiser 250/ GX550

[Winchester44]

USDOT crash safety regs also require that fuel tanks do not puncture in the event of a crash. This is tested prior to a vehicle's approval for sale in the US as far as I know. Chinese regs, who knows? Probably why Toyota will never offer an upgrade tank for the USDM LC250 and never offered them on other LCs.

Little more complicated. . FMVSS 301 doesn’t prohibit larger tanks — it just requires that a vehicle’s fuel system limit leakage after a crash to below certain thresholds. Plenty of U.S. trucks and SUVs run 30–40+ gallon tanks that meet those same standards.


The real hurdles for Toyota aren’t crash safety but CARB evaporative emissions and CAFE fuel econonomy for the US Fleet. . Every tank size has to be individually tested and certified, with its own vapor canister setup and emissions data. Thats the real driver of smaller tank. Toyota didn’t cut corners to save money. It was actually more expensive to design and certify the smaller tank to satisfy US regulators.

Toyota would absolutely run the larger global tank here — it’s cheaper to build one configuration worldwide. Unfortunately, US regulators know better.

You might be right on crash testing playing a role on not offering a sub tank. The post crash leak requirements will be tougher to meet with two of everything. Twice as many failure points.

 

[Winchester44]

I spent some time this morning underneath my LC.
Couple of takaways:

-while these is no telling until the new tank arrives whether it will truly fit, I will say the underside looks exactly the same as the test vehicle, near as I can tell and without removing anything. The exhaust routing, frame, driveline, etc are as expected visually identical. This is totally not surprising given the Chinese spec is the same dimensions and drivetrain and fuel tank capacity as the US spec and this is a global vehicle platform.

-the hoses and lines and wires appear to be in the right places, again not surprising given they generally lead to the top of the tank because many of them mount to the fuel pump and evap canister, so they can’t be far away or really even reconfigured if the system is using the same pump. Which it is.

-I was wondering where the extra tank size comes from-someone asked if the tank hangs lower because of the size and the answer Is I don’t think so. It appears in the photos to hang flush with the bottom of the frame. Which is +/- the same as the OEM tank.
So where does the extra capacity come from?
Visual inspection says it is longer, particular on the front end of the vehicle. There are several inches (3-4?) on the front end where the tank is longer and there is space for it. Height is also a possibility as there is space above the OEM tank- I could reach my hand up and over the tank no sweat. And dimensionally the OEM tank is relatively tubular vs the new one is squared, adding some capacity. And finally the OEM tank is molded and I believe from looking at it that the baffling and structural reinforcement is molded into the tank- but this creates sizable valleys all over the tank (think give or take 1-2” deep and running all over the tank. The new one is smooth leading to more capacity and presumably uses welded metal baffles which are probably very thin. Add it up and I guess it’s 11 gallons extra.

Anyways, no major obvious red flags from initial inspection. Will have to wait 45 days to actually take it apart and try to fit it.

Thank you sir!

 

[Winchester44]

From an aftermarket standpoint would it be safe to assume that the sub tank at least has the potential to be a more complicated installation with potent for more trouble down the road at least as relative to an aftermarket main tank replacement? I might be overthinking it. Would love the massive range increase from the sub tank, but sound like just a lot potential to mess something up. One benefit is it sounds like under this system sub tank your fuel level guage is going to be more accurate once the sub empties.

 

[Winchester44]

Has there been a consensus on how bad or not bad it is to run 87 octane?

 

[D-mac]

From an aftermarket standpoint would it be safe to assume that the sub tank at least has the potential to be a more complicated installation with potent for more trouble down the road at least as relative to an aftermarket main tank replacement?

Long Range America that specializes in making aftermarket fuel tanks estimates it takes 8 hours to install their tank. It's probably not a simple bolt-in to do correctly?

 

[doubleD]

From an aftermarket standpoint would it be safe to assume that the sub tank at least has the potential to be a more complicated installation with potent for more trouble down the road at least as relative to an aftermarket main tank replacement? I might be overthinking it. Would love the massive range increase from the sub tank, but sound like just a lot potential to mess something up. One benefit is it sounds like under this system sub tank your fuel level guage is going to be more accurate once the sub empties.

For CERTAIN a sub tank is far more
Complicated to install. Most of them require welding near gas lines and receptacles. You have electronics, switches, relays etc. extra hoses and an extra filler line and so on. The main tank is generally remove and replace.
The upside to an aux tank to your point is more capacity; but from the options available the saddle style aux tanks don’t add much more capacity than just upgrading the main tank. You have to go into the spare tire location to get the huge capacity gain.
All in you’re looking at $2650+ for the LRA models plus 8 hours of install time. Most skilled labor around me is upwards of $150 a hour, so figure $4000 all in.
To me that is just way over the line of what it is worth. I think for me you push $2000 and the value is hard to justify. If I was going to be overlanding for days at a time with no gas for hundreds of miles and I was doing new bumpers anyways, and could put a tire on the rear bumper then perhaps I could get my head around a 24 gal sub tank in the OEM spare location. But, I’m not doing any of that. I just want to be able to take a car trip without stopping half a dozen times because there’s no gas for 80 miles.

 

[Winchester44]

For CERTAIN a sub tank is far more
Complicated to install. Most of them require welding near gas lines and receptacles. You have electronics, switches, relays etc. extra hoses and an extra filler line and so on. The main tank is generally remove and replace.
The upside to an aux tank to your point is more capacity; but from the options available the saddle style aux tanks don’t add much more capacity than just upgrading the main tank. You have to go into the spare tire location to get the huge capacity gain.
All in you’re looking at $2650+ for the LRA models plus 8 hours of install time. Most skilled labor around me is upwards of $150 a hour, so figure $4000 all in.
To me that is just way over the line of what it is worth. I think for me you push $2000 and the value is hard to justify. If I was going to be overlanding for days at a time with no gas for hundreds of miles and I was doing new bumpers anyways, and could put a tire on the rear bumper then perhaps I could get my head around a 24 gal sub tank in the OEM spare location. But, I’m not doing any of that. I just want to be able to take a car trip without stopping half a dozen times because there’s no gas for 80 miles.

Yeah that’s kind of where my head is at for the moment. The 29 gallon replacement is 62% more than the factory 17.9. Big improvement with less work and long term worry.

 

[doubleD]

Has there been a consensus on how bad or not bad it is to run 87 octane?

You can run it on a modern car but it isn’t worth it imo. You’ll get crap power and mileage because the ecu will cut timing to prevent detonation/knock. Also will cut boost. And you’ll get excess heat everywhere from the cylinder downstream which will eventually lead to carbon buildup and component failure.
Not to mention probably really easy to tell if a car has been running 87 for warranty purposes.

 

[EOD Guy]

I run 87 ..... plenty of power, ECU may be adjusting timing but that's exactly what it's supposed to do and only if the knock sensors pick up the frequency. Turbo spools up just fine. Combustion is just that, a detonation (combustion) is the result of igniting a fuel air mixture, using a higher octane would produce a hotter more powerful explosion which equates to more heat , not less.

I do not deny higher octane will produce more power, thus more exhaust gasses and therefore faster turbo spool up......... But not the rest.

 

[doubleD]

I run 87 ..... plenty of power, ECU may be adjusting timing but that's exactly what it's supposed to do and only if the knock sensors pick up the frequency. Turbo spools up just fine. Combustion is just that, a detonation (combustion) is the result of igniting a fuel air mixture, using a higher octane would produce a hotter more powerful explosion which equates to more heat , not less.

I do not deny higher octane will produce more power, thus more exhaust gasses and therefore faster turbo spool up......... But not the rest.

I think the heat thing is a function of timing, not power. The 91 doesn’t burn hotter. The power comes from higher compression at the point of ignition due to timing, but it doesn’t change the temps. Sort of like… burn some loose gun powder; it just fizzles up. But it burns at the same temp as it does in a cartridge in a barrel, but when in the cartridge things go boom. And water boils at 212 regardless of in an open pot or in a steam engine.
Power output will be down from less compression at the point of ignition but it doesn't burn hotter per se.
But the retarded timing is the issue- less complete burn in the cylinder and more burns after exiting the cylinder. That means direct burn downstream and hence hotter exhaust temps. It’s not a function of total heat, it’s about where the heat gets released due to timing changes made by the ecu due to octane rating. Retarded timing results in hotter temps.
That said, it may or may not be a big deal, certainly not in the short term, long term who knows but sounds like you’re testing it for us. It may all fall within spec and be just fine.

 

[EOD Guy]

I disagree .......The difference between a powder burn (deflagration) and an explosion, is the speed at which the substance burns. Why doesn't all powder burn at the same rate (which it most certainly does not), purity of the base substance and additives. Why doesn't all gasoline burn at the same rate, regardless of octane, purity of the base substance and additives. Compression just squeezes the mixture into a denser substance and timing ignites the compressed substance at the right moment for maximum power per stroke. The valves shut off the intake or exit of the substance from the combustion chamber, a lean mixture will burn hotter than a rich mixture regardless of when it was ignited. Hence higher compression should use higher octane. Higher octane equals potentially higher BTUs. While I'll agree if there's a malfunction in the timing circuit/valve train some weird things might happen, but that would be the exception, not the rule.

I run all my vehicles on 87 about 90% of the time with zero issues. The last BMW had in excess of 240K on the ticker when it went to a new home, ran like a top. I do not have an issue with people burning what ever flavor of fuel they desire or having a difference of opinion to mine, but some portray octane as if it's "the only" way, some even pointing out the sticker on the fuel door "Only" (which I find quite humorous).

 

[Midwest Duo]

I run all my vehicles on 87 about 90% of the time with zero issues. The last BMW had in excess of 240K on the ticker when it went to a new home, ran like a top. I do not have an issue with people burning what ever flavor of fuel they desire or having a difference of opinion to mine, but some portray octane as if it's "the only" way, some even pointing out the sticker on the fuel door "Only" (which I find quite humorous).

I know next to nothing fuel science and combustion engines (or BMWs). Just curious if all your vehicles were turbos?

 

[EOD Guy]

I know next to nothing fuel science and combustion engines (or BMWs). Just curious if all your vehicles were turbos?

No Just one. All a turbo is, is an air pump driven by exhaust gasses. Fuel map and injectors or Carb/Jets and blow off valve/bypass all have to be calibrated to match for optimum power.

I did put a turbo on a lawn mower once but it ran on 87 as well........

 

[t3lcfe]

Wow…this topic is growing every day and piled up with tons of information/discussions…but looks
Like the end / result is still far.
I am listening, learning, and confusing myself and keep listening every single talk here…: Why Toyota decided to have small fuel tank / shorten travel distance between gas filling stops…? To meet US market and safety regulations…Consumers and aftermarket try to have larger fuel tank…any risk of not meeting regulations … etc. ? Pros and cons…?

Like “most” of us here…I do love everything about this LC250, except small fuel tank…For now, I just “live” with couple Rotopax fuels, and many stops for gas on long 5-10 hrs drive. Just think positively that I have chance for many leaks

 

[EOD Guy]

Wow…this topic is growing every day and piled up with tons of information/discussions…but looks
Like the end / result is still far.
I am listening, learning, and confusing myself and keep listening every single talk here…: Why Toyota decided to have small fuel tank / shorten travel distance between gas filling stops…? To meet US market and safety regulations…Consumers and aftermarket try to have larger fuel tank…any risk of not meeting regulations … etc. ? Pros and cons…?

Like “most” of us here…I do love everything about this LC250, except small fuel tank…For now, I just “live” with couple Rotopax fuels, and many stops for gas on long 5-10 hrs drive. Just think positively that I have chance for many leaks

Should that OEM Aux tank ever become affordable in the US, I'll go that route, regardless if I ever get the GX tank to fit. Almost done with my puddle light project, might just start messing with the GX tank.

 

[Winchester44]

Should that OEM Aux tank ever become affordable in the US, I'll go that route, regardless if I ever get the GX tank to fit. Almost done with my puddle light project, might just start messing with the GX tank.

The heat gun option?

 

[Winchester44]

I think the heat thing is a function of timing, not power. The 91 doesn’t burn hotter. The power comes from higher compression at the point of ignition due to timing, but it doesn’t change the temps. Sort of like… burn some loose gun powder; it just fizzles up. But it burns at the same temp as it does in a cartridge in a barrel, but when in the cartridge things go boom. And water boils at 212 regardless of in an open pot or in a steam engine.
Power output will be down from less compression at the point of ignition but it doesn't burn hotter per se.
But the retarded timing is the issue- less complete burn in the cylinder and more burns after exiting the cylinder. That means direct burn downstream and hence hotter exhaust temps. It’s not a function of total heat, it’s about where the heat gets released due to timing changes made by the ecu due to octane rating. Retarded timing results in hotter temps.
That said, it may or may not be a big deal, certainly not in the short term, long term who knows but sounds like you’re testing it for us. It may all fall within spec and be just fine.

You’re exactly right that octane itself doesn’t make the mixture burn hotter — the temperature is mostly a function of the fuel-air ratio, not the octane rating. The main variable is timing — when and where that heat gets released.





Running 87 in a tune that expects 91–93 means the ECU has to pull timing to keep knock in check. That tends to move more of the burn downstream, which can show up as higher exhaust gas temps even though total combustion heat isn’t necessarily higher. It’s less about more heat overall, and more about where it’s happening.





Whether that matters probably depends on how conservative the tune is and how much margin the components have for sustained EGTs. In the short run, most ECUs will handle it fine; long term, hard to say — might just come down to how often and how hard it’s pushed. Sounds like you’ll get some good real-world data either way.

 

[EOD Guy]

The heat gun option?

Yepper and some wooden bucks to keep it from collapsing where I don't want it to.

 

[grandsons]

I'm just curious, in the US you can mount just any tank like that? no regulation? Because here in Europe depending on vehicle age, there is a certification to meet. There is always a certification if you plan to mount anything .

I just looked at the paper here https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:42011X0428(02)&qid=1759820832485 which tells a lot about fuel tanks. Technically speaking it's quite interesting, for example how a tank is tested and for what purpose.

Concerning this Chinese tank, it look sturdy and very well weld. Don't be fool by cheap Chinese crap, there are very skilled poeple overthere, capable offering of quality items.

My main concern is how the mounting belts and bolts will perform during a crash and the lack of space between frame or components and tank. Some rare crash test images taken from underneath vehicles show parts like gearbox, rods etc... protruding into spaces left empty in the chassis specifically for this purpose. A tank filling these spaces is likely to become stuck, with a risk of perforation.

 

[RUN-8]

Europe sucks.