I wanted to share some of my thinking on the Tembo/exel aux tank install a bit as the 200 goes into the shop for installation of the Aux tank this week. I was going to do the install myself, but work always gets in the way of the best-laid plans.
A little background, while 60L/15 gallons does not seem to be a huge difference, it will allow for about 150 to 175 mile additional range on the highway. I am a little heavy on the skinning peddle, the rig is heavy, weighs in at about 7300lbs, running 4.88s, then once you add the ski box, rhino rack, max trax, etc and family of 4 adventure gear + a dog, well you get the picture… I average about 10.5 MPG on the Hwy, slowing down to 72 MPH allows for the engine to rev around 2100 PMs in 6th which increases the HWY MPG to 14.0 MPG when laden. A 200-mile range (maybe the 300 will have a 300-mile range) was fine when the Kidos were younger because we ended up stopping for potty stops every 2 hours. But, now we have learned to actively dehydrate the kidos and the dog through prohibition of drinking fluids while road tripping (kidding) they can last 5 hours without a pee break. So 375 range between fill-ups is about ideal for us.
Observation 1: The non-us spec 3UR-f3 (5.7) 200’s with a sub tank have the evap canister in front of the main tank, but the schematic does not show any wiring harness. Also, non-us 3UR-f3 200’s do not seem to have a vapor filter (us part #77706-60040)- indicating the emission controls are more passive in nature than the US-Spec and not controlled by the ECM. I think the target is mounting the evap canister in front of the main tank or in rear passage wing, behind the rear tire between the frame and outer body. Both locations will require an extension of hoses and maybe the wiring harness. The kit does not come with any parts (hoses, wiring, or brackets to relocate the evap canister or the vapor filter).
If possible, I would like to try to figure out a relocation that only requires additional hoses and not extending the harness, but I think that might be a pipe dream.
The non-us and us vapor canister (us part 77740-60470) looks to be about the same size as the non-us spec. So I am less concern about vapor maxing out the canister before a purge cycle being initiated by the PCM-
Observation 2: The instructions call for drilling a fill hole in the main tank- near the primary fill entrance. Seems straight forward… I think this where if anywhere there might be the opportunity to introduce an air leak into the fuel system impacting the pollution control system. This is how the Aux tank gravity feeds the main.
Observation 3: The Tembo/exel tank seems to have one vent to support filling and one fuel evaporation via the aux to main fuel filling path- this also serves a reverse vent to aid in gravity fuel transfer. The OEM sub tank seems to have one vent to support filling, two dedicated vents connected to the main and one via fuel filling path. I thought about putting a “ T” into the EVAP canister from the new Aux tank, I think that is an unnecessary complication.
Observation 4: per the instructions, the tire rack mounting bracket requires drilling holes through the rear floor, the ARB Drawers might be in the way. There is a replacement bracket that leverages the OEM spare tire lift system. Plus, to access (if required) the main tank fuel pump/sender/jet pump we will have to take the Drawers out or drop the main tank.
Observation 5: After reviewing of the Tundra service manual, eyeballing a neighbor’s Tundra and then eyeballing the 200. The EVAP system seems to be the same as the Tundra’s. My primary area of concern around throwing codes is when the system performs a self-test as it pressurizes the system to determine if there are air leaks. With the addition of the AUX tank, there will be more volume to pressurize with the addition of the AUX tank. I guess I will find out if the self-test cycles have some sort of time limit to pressurizing the system. Again, it seems this is not an issue on non-US spec 5.7 with the OEM sub tank as the evap system seems to be more passive than the US spec. I am less concern that computer will have issues with system doing what is design do and more concern about the self-test cycles.
Observation 6: The Aux fuel tank first completely fills, then effectively overflows into the main to complete the tank filling process at the pump. Simplicity, yes. One can add more fuel to the Aux tank and it will gravity feed the main. To only fill the main one will have to do a little math at the pump, or if using jerry cans, you will have add time for fuel to flow from the aux to main via the gravity feed line.
Observation 7: The distance to empty and MPG since last fill will not work unless there is a way in the TIS to change the tank size. Using the trip computer will work fine for me, the wife, on the other hand, thinks the orange empty lamp is a challenge vs. a warning.
Observation 8: When considering the relocation of the EVAP canister, it seem the orientation needs to stay similar to the original installation. Thoughts? Do you think it would work the same rotating it 90 degrees?
Thoughts and comments?
I will provide an update once the installation is completed- the shop I am having work done is committed to taking photos along the process, so I will share those as well.
A little background, while 60L/15 gallons does not seem to be a huge difference, it will allow for about 150 to 175 mile additional range on the highway. I am a little heavy on the skinning peddle, the rig is heavy, weighs in at about 7300lbs, running 4.88s, then once you add the ski box, rhino rack, max trax, etc and family of 4 adventure gear + a dog, well you get the picture… I average about 10.5 MPG on the Hwy, slowing down to 72 MPH allows for the engine to rev around 2100 PMs in 6th which increases the HWY MPG to 14.0 MPG when laden. A 200-mile range (maybe the 300 will have a 300-mile range) was fine when the Kidos were younger because we ended up stopping for potty stops every 2 hours. But, now we have learned to actively dehydrate the kidos and the dog through prohibition of drinking fluids while road tripping (kidding) they can last 5 hours without a pee break. So 375 range between fill-ups is about ideal for us.
Observation 1: The non-us spec 3UR-f3 (5.7) 200’s with a sub tank have the evap canister in front of the main tank, but the schematic does not show any wiring harness. Also, non-us 3UR-f3 200’s do not seem to have a vapor filter (us part #77706-60040)- indicating the emission controls are more passive in nature than the US-Spec and not controlled by the ECM. I think the target is mounting the evap canister in front of the main tank or in rear passage wing, behind the rear tire between the frame and outer body. Both locations will require an extension of hoses and maybe the wiring harness. The kit does not come with any parts (hoses, wiring, or brackets to relocate the evap canister or the vapor filter).
If possible, I would like to try to figure out a relocation that only requires additional hoses and not extending the harness, but I think that might be a pipe dream.
The non-us and us vapor canister (us part 77740-60470) looks to be about the same size as the non-us spec. So I am less concern about vapor maxing out the canister before a purge cycle being initiated by the PCM-
Observation 2: The instructions call for drilling a fill hole in the main tank- near the primary fill entrance. Seems straight forward… I think this where if anywhere there might be the opportunity to introduce an air leak into the fuel system impacting the pollution control system. This is how the Aux tank gravity feeds the main.
Observation 3: The Tembo/exel tank seems to have one vent to support filling and one fuel evaporation via the aux to main fuel filling path- this also serves a reverse vent to aid in gravity fuel transfer. The OEM sub tank seems to have one vent to support filling, two dedicated vents connected to the main and one via fuel filling path. I thought about putting a “ T” into the EVAP canister from the new Aux tank, I think that is an unnecessary complication.
Observation 4: per the instructions, the tire rack mounting bracket requires drilling holes through the rear floor, the ARB Drawers might be in the way. There is a replacement bracket that leverages the OEM spare tire lift system. Plus, to access (if required) the main tank fuel pump/sender/jet pump we will have to take the Drawers out or drop the main tank.
Observation 5: After reviewing of the Tundra service manual, eyeballing a neighbor’s Tundra and then eyeballing the 200. The EVAP system seems to be the same as the Tundra’s. My primary area of concern around throwing codes is when the system performs a self-test as it pressurizes the system to determine if there are air leaks. With the addition of the AUX tank, there will be more volume to pressurize with the addition of the AUX tank. I guess I will find out if the self-test cycles have some sort of time limit to pressurizing the system. Again, it seems this is not an issue on non-US spec 5.7 with the OEM sub tank as the evap system seems to be more passive than the US spec. I am less concern that computer will have issues with system doing what is design do and more concern about the self-test cycles.
Observation 6: The Aux fuel tank first completely fills, then effectively overflows into the main to complete the tank filling process at the pump. Simplicity, yes. One can add more fuel to the Aux tank and it will gravity feed the main. To only fill the main one will have to do a little math at the pump, or if using jerry cans, you will have add time for fuel to flow from the aux to main via the gravity feed line.
Observation 7: The distance to empty and MPG since last fill will not work unless there is a way in the TIS to change the tank size. Using the trip computer will work fine for me, the wife, on the other hand, thinks the orange empty lamp is a challenge vs. a warning.
Observation 8: When considering the relocation of the EVAP canister, it seem the orientation needs to stay similar to the original installation. Thoughts? Do you think it would work the same rotating it 90 degrees?
Thoughts and comments?
I will provide an update once the installation is completed- the shop I am having work done is committed to taking photos along the process, so I will share those as well.
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