600 Miles on One Tank

[a2b]

600 Miles on One Tank.

this is my goal.

so this is what i figure. i can get 2, 10 gallon gas cans, weld them together at their ends. lay it up on its side against the front of the bed. run the gass filler tube from the stock tank, to the a welded hole in one of the aux tanks. then from the orginal filler hole in one of the aux tanks, run a line from it to the original filler hole from the side of the truck.



any questions? whatcha think?



and yes yes i know its illegal, but i can hide it



the reason i why i say 2, 10 gallon gas tanks instead of just a 20 gallon fuel cell, is because of the shape. i can weld the 2 gas cans bottom to bottom and lay them sideways, which will be low enough to still use the orginal filler tube open from the side of the bed.

[HenryJ]

Hmmm...I'm not sure you could get it to work that way. What about the vapor recovery system? You'd probably set the SES.

How about using the tank you have described (Have one custom built ,or one of the add-a-tanks from Jc Whitney) then wire an electric fuel pump and plumb it to a Tee fitting spliced into your filler neck hose. When you notice you're getting low on fuel , kick the pump on and fill it back up.

Another advantage to this is during a gas crunch, park close to your neighbors car and slide a piece of hose into his tank, pump away

But don't tell the cops where you got the idea, when you get caught!

[Conman]

They have legal in bed tanks. Seen them on 5th wheel pickup beds. Yeah our 17.5 gallon tanks are way too small.



Con

[a2b]

Another advantage to this is during a gas crunch, park close to your neighbors car and slide a piece of hose into his tank, pump away

But don't tell the cops where you got the idea, when you get caught!

now that is the best mod yet!!!! i love it.



well, i dont think it would be a problem, its would still be all air tight, right? so the vacum would still be there, so why would it mess things up?

[HenryJ]

The tank in the back would have to be vented. It will be exposed to higher temps from the summer heat and , I don't believe that the VRS would handle the extra load. JMO

[a2b]

The tank in the back would have to be vented. It will be exposed to higher temps from the summer heat and , I don't believe that the VRS would handle the extra load. JMO

vented??? then it would leak in the bed



and what is the VRS?

[HenryJ]

what is the VRS?

Vapor Recovery System

[a2b]

well the heat is definetly something to be considered, but my bed is covered all the time and i was going to put another shiled around it anyways.



so how the VRS work in the stock gas tank as it is? can it be modified to include the extra tank?

[HenryJ]

so how the VRS work in the stock gas tank as it is? can it be modified to include the extra tank?

I guess I should call it correctly the EVAP (Evaporative Emission) System.

It condenses the fuel vapors and returns them to the tank and/ or transfers them to the intake where they are burned.

Can it be modified? Anything is possible, the suburbans run a 40+ gal tank. Parts could be switched I guess.

I really don't know enough about this to make any recomendations.

The 2001 PCM is very sensitive to messing with it's systems though. I've heard that a loose gas cap will set the SES light. I can't imagine what the mod you are describing would do.

[a2b]

i know about the evap system, it would still work. all i am doing is splicing into the filler tube and putting a 20gallon tank. everything would still work right.

[HenryJ]

That's what I think , everytime I try to change things too

Good luck, Let me know how it works out. You da "guinea pig" on this one

[a2b]

well i dont mind being the guinea pig. this is one mod i have wanted to do since i have had the truck.



so do you have any other ideas or look outs or input on the process. things i need to take into consideration?

[HenryJ]

I really don't know what all you'll run into, for problems.

I'm going to add the "Tee" (2"x5/16") to my filler hose, add a small "autoparts cheapie" fuel pump, attach a marine outboard fuel line quick connect, and have an (boat) outboard fuel tank in the back.

That way I can toss it in the back for the long trips and don't have to pack it all the time

If I start to run low on fuel I'll hit the switch and fill up.



My Dad did something similar to this on his VW van many years ago. It was nice to have that untouched reserve tank.

Kind of like the older motorcycles. You always knew that you had a gallon left to get back when it ran out.

[a2b]

that sounds good too

[HenryJ]

Well thanks alot...Hobie You talked me into it

I ordered a 20 gal tank, that will fit in the bottom of my toolbox , some male and female quick connect fittings.

Ibought a NAPA fuel pump (#610-1050), two 3/8MIPx5/8"barb fittings, one 3/8"MIPx3/8"barb fitting and a 3/8"FIP tee, to install into the fuel filler vent line (I decided it was an easier place to tie in).

I already have the fuel line, switch, relay, fuse, wire, and hose clamps.

My total cost should be about $180



This should give me a total of 39 gal. (37gal. useable?) , allowing a range of 550 city/offroad and 750mi all highway.



Plus I'll be able to use the tank in my boat, if needed, for a greater range too.

[a2b]

YES!!! this is the most exciting mod yet!!! i will do it too!

[Conman]

Well thanks alot...Hobie You talked me into it

I ordered a 20 gal tank, that will fit in the bottom of my toolbox , some male and female quick connect fittings.

NAPA has a small fuel pump (#610-1050). I'll get a tee, to install into the fuel filler vent line (I decided it was an easier place to tie in).

I already have the fuel line, switch, relay, fuse, wire, and hose clamps.

My total cost should be about $180



This should give me a total of 39 gal. (37gal. useable?) , allowing a range of 550 city/offroad and 750mi all highway.



Plus I'll be able to use the tank in my boat, if needed, for a greater range too.

Will there be any static discharge issues with the plastic tank and the bedliner? Also, is your toolbox plastic also? I remember the warnings about filling up a plastic fuel tank in a pickup bed with a plastic bed liner. They recomend filling it up on the ground.



Con

[a2b]

yes that is a good call. i thought about it already. if i do it, i am takeing my bedliner out and going line x. but i dont have a tool box like brule? so what are you going to do brule?

[HenryJ]

Will there be any static discharge issues with the plastic tank and the bedliner? Also, is your toolbox plastic also? I remember the warnings about filling up a plastic fuel tank in a pickup bed with a plastic bed liner. They recomend filling it up on the ground.

Yes the box is plastic also. I don't forsee any problems, as long as the filler and hold downs are grounded. You have to use common sense and discharge any static electricty before fueling.

At least there should be no more risk than the zap I get everytime I get out of the truck.

There would be some concern if the fumes were to accumulate in the bed of the truck.

If you see a flash, and hear a boom from my direction, you'll know that this wasn't such a good idea

[a2b]

hahahaha. i know i know, why the heck do i get shocked every time i get out of the truck

[HenryJ]

Well the last of the parts arrived today.



So, My son Tach, and I will hopefully be busy installing them this weekend

[a2b]

cool, cant wait to see how it works!

[Conman]

Do you think you can put that under the truck, say where the spare is?



What about a bigger replacement gas tank? I would be game for that as My bed is small enough already.



Cheers,

Con

[HenryJ]

The Marine tanks come in all different sizes and shapes. If you were to add one without a tool box, one of the thin uprights would be nice.One that fits the front of the bed under a tonneau cover.



Of course there are automotive fuel cells that will fit where the spare tire is , and for that matter if you want to put one there a blazer fuel tank would be the obvious choice. Then you'd have a fuel pump and truly a second tank and fuel system.

I didn't want to move the spare and had some concerns about a fuel tank hanging there.



As for a bigger tank , I really don't want to add much more than the 120 lbs. and with my range being doubled with a little to spare I'll be happy.



I do have some concerns as to how well this is going to work. That is one reason I bought a tank that will work in my boat. If this doesn't work very well I will still have a use for it.

[a2b]

ya, i like that box there. might be considering it

[HenryJ]

last night I installed the tank , mounted the pump, ran the fuel line, and vent line.

Today I had my helper, so I wired the switches and relays. All I have left to do is run one wire to the fuel pump, but my "helper" got tired and cranky.Hopefully I'll finish it later tonight.



FYI: the loose connector and wiring behind the blank panel (right of inst. cluster , below 4x4 switch) is for the rear wiper and hatch release switch in the Blazers.

I picked up one at the salvage yard to use for my aux. fog lights and the aux. fuel tank. So far it is a pretty easy way to wire the system. I removed the three wires that supplied the hatch release, rear wiper, and rear washer, taped them back and added my acessories.

The plug has the dash light wire, a battery positive, ignition positive, and ground , that I am now using.

The wiper switch is now my aux. fog light switch, and will be my aux. back-up light switch (when I install one). The hatch release activates the fuel transfer pump relay.



Plumbing the fuel line was a real pain. Things are really tight.

I drilled a 1" hole in the bed just off center of the left front drain hole and installed a grommet. Then drilled a 1" hole in the left bottom corner of the bed liner and the bottom corner of my toolbox. I used a grommet in the tool box too.



I mounted the fuel pump on the outside of the frame , just in front of the left rear cab mount.



The stock fuel tank vent line was easiest to cut right between the cab and bed, so that is where I installed the tee.

Well that's where I'm at for now, I'll add to this when I get it finished.

[a2b]

cant wait

[HenryJ]

Finished the install.



More pictures and a description

[a2b]

so does it work?

[HenryJ]

Yes, and I'm not sure.

It does transfer the fuel just fine. I filled up a quarter tank of fuel tonight as I was driving down the road. The only thing I am unsure of is if it will continue to siphon fuel and overfill.

I'm hoping that the fuel pump being off will create enough pressure restriction to prevent this.

I'll let you know if I have to add a check valve.



EDIT: It does indeed siphon fuel! So I am going to have to add a shutoff. I'm thinking about adding one to the electric fuel selector valves and capping off the unused connection. Seems to be the least expensive option at this time.

[quickbiker]

LOL, that reminds me of my demolition derby days. I used to mount the tank in the trunk. I just used a plastic fuel tank and ran the lines in there. But those were the days of mechanical fuel pumps, so it was easier.



I guess if you hooked up a switch to the pump, then you could just hit it when you were low on fuel, and you can watch the gauge go up and shut it off when full, LOL.

[HenryJ]

I guess if you hooked up a switch to the pump, then you could just hit it when you were low on fuel, and you can watch the gauge go up and shut it off when full

You got it that's exactly what I am doing!

[HenryJ]

The fuel tank selector valve was installed last week.





It is being used as a shut-off valve. You can see that I capped off the normally open connection and used the normally closed line. When I energize the pump it opens the valve.



Everything is working as planned now. The only thing I have left to do is add a small LED, so that I have a visual indicator that the pump is running to fill the main tank.

Maybe someday I'll add an interior fuel guage for the aux. tank. There is a mechanical fuel guage on the tank , but one inside might be nice.

[quickbiker]

lol, I really like your project there. I would like the idea also, but I would really feel like a gas hog if it took me $50 to fill up.

[HenryJ]

I would really feel like a gas hog if it took me $50 to fill up.

Yeah, I know what you mean But I only have to fill once a month now

And for those long weekends in the hills , it will be nice to have the expanded "point of no return" (half tank plus 1 gallon)

[a2b]

ya i really wanted it when i drove from louisiana. i hate stopping for gas.

[HenryJ]

Well I'd say that I'm finally finished with this mod.

It does work pretty nice (I am still working on the second tank of fuel through it)



Hind sight is 20/20 so here is some fore sight for you.



#1- Plan on installing a fuel gauge from the beginning.That way you don't have to wonder if you are pumping a dry tank. It is a PITA to disassemble everything just to run two wires And a whole lot safer to install the fuel sender on a fresh fuel free tank.



#2- Get a tank 25% larger than the fuel you want to have. I think during the summer months 15 gal is about all I will be able to run, in order to have enough room for expansion and the amount the pick-up won't get.



#3- If you are an impatient sort, go for a fuel pump that moves more GPH. I installed a cheap 35 gph pulse pump. It works fine, but I may put one of my old Holley "Blue" pumps on if I decide I want to move the fuel twice as fast.



All in all , I'm pleased now. FYI, Hobie I don't think I'll quite make the "600 miles on one tank" with city driving, but it is much better than the stock fuel capacity.

[a2b]

ya, i was just off roading with a taco who had an aux tank. he mounted it where the spare tire used to go. he said just what you did, the gas will heat up in the summer and will expand. so he said to make sure it was vented with the same vent line from the main tank.



sounds like you did a great job!

[Brad]

I called a fab shop to make a 31x31x2 tank to mount above my spare since I have a body lift. 500 bucks they said. WOW. Any ideas?



Brad

[Conman]

I called a fab shop to make a 31x31x2 tank to mount above my spare since I have a body lift. 500 bucks they said. WOW. Any ideas?



Brad

On the fullsize pickups, I've seen the extra tank where the spare was. Might be much cheaper just to take the spare out and mount a tank there. You could mount the spare in the bed, or maybe get one of those hitch/bumper mounted spare tire holders like on SUVs.



Cheers,

Con

[HenryJ]

Thought I'd add a quick update:

Last tank I went 540 miles before filling up! I still had just under a 1/4 left in the main tank!

I may very well be able to get the 600 miles if the majority is highway

[AZS10Crew]

I could have used this spare tank last weekend camping. I got off the freeway with 1/4 tank left. 20 miles later at the campground my low fuel light came on. I love GM gas gauge accuracy!

[HenryJ]

That is another thing I like about the transfer tank. I don't have to rely on the main tank guage for my "point of no return"

Playing with the stock guage when refueling, I have noticed a few things:

While adding fuel "on the go" the stock guage does not rise as fast or acurately as the after market gauge on the aux. tank. After an ignition cycle it seems to recover to a correct level.



I tend to rely on the aux. tanks gauge and the top half of the main tanks gauge. Works pretty well.

[a2b]

i want to do this mod very badly. i am so tire of filling up every 200 miles

[HenryJ]

From the beginning of this thread it has taken me almost three years, but I finally have in place a system that can far exceed the goal of 600 miles

Auxilary Fuel Tank

[kf6kmx]

Will there be any static discharge issues with the plastic tank and the bedliner? Also, is your toolbox plastic also? I remember the warnings about filling up a plastic fuel tank in a pickup bed with a plastic bed liner. They recomend filling it up on the ground.

Yes the box is plastic also. I don't forsee any problems, as long as the filler and hold downs are grounded. You have to use common sense and discharge any static electricty before fueling.

At least there should be no more risk than the zap I get everytime I get out of the truck.

There would be some concern if the fumes were to accumulate in the bed of the truck.

If you see a flash, and hear a boom from my direction, you'll know that this wasn't such a good idea

Actually the zap getting out of the truck solves your problem... that discharges you.. For the most part the problem with the plastic tanks in the bedliner ISNT the tanks, its the fact that the person filling them hasnt gotten dischaged yet.. the tanks arent moving/generating static, you are getting in/out of the truck, coat, clothes, etc.
When you get zapped on your door getting out, you are generally safe until you get back in and out again and build a new charge.

On the tank, if you run a ground from the truck bed to some sort of metal on the tank around the filler, that will ground the tank out also.

They did a study (I do volunteer with CDF fire and they were showing up the results of the study).. The fire blamed on cell phones (all the 'cell phones prohibited around this fuel pump' signs) is WRONG.. The fire agency that did the study, the NTSB, and the FCC (I guess they decided to test it since they are in control of the phone specs) could not get a single fire from even a malfunctioning cell phone..
All the fires they studied, were nozzle fires, and 90% were caused by women.. They found that most men start the pump and stay outside the vehicle, either with the nozzle, or washing the windshield.. most women started the pump, GOT BACK IN THE CAR to wait (building a static charge) then got out and the FIRST thing they touched was the nozzle, causing the spark and fire..
Their study concluded that the cell phones WERENT the problem, but the static from getting back in the car was, but that the 'shut up and drive' anti-cellphone crowd had jumped on the idea of blaming cell phones for yet another major woe of society and it had gone from incorrect, to myth, to 'generally accepted at face value'..

[HenryJ]

600 Miles on One Tank.

this is my goal...

Just passed 700 miles on one fill and still going.

[killian96ss]

Just passed 700 miles on one fill and still going.

700 MILES I'm sure the mpg increase with the 33's helped also!

Steve

[HenryJ]

Well I chickened out and filled up today.
I made it 780 miles before filling I still had over a 1/4 tank left, but hate to run the main tank that low. It took 48 gallons to fill all three tanks. That puts the mileage around 16.25, with as cold as it has been, and primarily city / offroad driving, I would say the mileage has improved slightly since adding the 33" tires.

[HenryJ]

I removed the marine tank and toolbox today. After the Moab trip , I decided I just did not need that much fuel. I did not touch the fuel in the Isuzu tank on that trip. I just no longer see the need for the marine tank in the toolbox. I installed it with quick connectors so throwing it in the back is still possible. With it and the toolbox removed, I can and have installed the Softopper that I picked up over a year ago.

This is the last long range run , I would suspect.



I fueled in Moab , UT just before we headed to the White Rim Trail. 770 miles later on the way home I refueled. That tank saw 17.1 mpg. Not bad at all considering the offroading done for three days.

[F9K9]

..................I fueled in Moab , UT just before we headed to the White Rim Trail. 770 miles later on the way home I refueled. That tank saw 17.1 mpg. Not bad at all considering the offroading done for three days.

[roadrunner]

Dude!! Is that an extra gas tank in place of your spare tire under box mount in that pic?? If so, what's it out of? Does it have it's own fuel pump or transfer pump? Don't look like my 01 underneath!

[HenryJ]

Dude!! Is that an extra gas tank in place of your spare tire under box mount in that third pic??

It is. My spare rides on the swing away carrier.
That goes back a long way: 600 Miles on one tank

Auxillary fuel tanks

You are going to have to snoop around my web page a little more so I don't surprise you again. The link is in my signature ThunderII

[roadrunner]

Interesting. Any suggestions on the filler location for those of us who have an open top box? (no cap) A hole in the bottom of the bed would tend to attract snow/trash etc especially for those of us without a garage. Consider me justifiably chastened. I did some "snooping" around on your site. Interesting and informative.

[HenryJ]

Interesting. Any suggestions on the filler location for those of us who have an open top box? (no cap) A hole in the bottom of the bed would tend to attract snow/trash etc especially for those of us without a garage.

I ran uncovered for years with no problems. I will grant you that it can be a pain when frozen over. The cup does have a drain hole and is not too bad to clear of trash when I need to. Perhaps a cover could be fabbed for the hole?

Consider me justifiably chastened. I did some "snooping" around on your site. Interesting and informative.

No need to feel that way, I was just joking Actually I was hoping you might find something more that looked interesting

[roadrunner]

Interesting and informative.

Actually I was hoping you might find something more that looked interesting

Actually it was all interesting. Main reason I missed the web page was I missed the word as a link in your sig line. I just tend more to the stock side since my CC is a work truck hence performance/mileage/durability issues tend to interest me more than many other extras. Nice looking truck you've got there it's just beyond what I want to do to mine. The extra gas tank interested me for reasons you might not expect. I've been thinking of relocating my spare to the box and that extra gas tank would certainly be more welcome than the mud/snow that tends to build up there whether the spare is there or not. Probably even more would build there in the absence of the spare. Not to mention if the main pump fails I'm thinking an extra tank with it's own pump could get me out of a jam till repairs could be effected. Along that thought line do you think there's any chance an OE pump could be located in that tank that's compatible with our systems directly using existing wiring (with auxiliary switch of course) that could function in place of the current stock in-tank setup on our trucks now? Are you running yours that way now or did I misunderstand that it's only a spare that pumps into the original tank?

[roadrunner]

One further question. Is that tank out of a 2.6 or a 2.8 engine trooper? Or are they the same tank? I ask because car-part.com calls them out that way.

[HenryJ]

Actually it was all interesting.

Thank you. Hopefully others will see it now as well.

I just tend more to the stock side since my CC is a work truck hence performance/mileage/durability issues tend to interest me more than many other extras.

That is foremost on my mind as well. I lean toward the light expedition side too though.

... if the main pump fails I'm thinking an extra tank with it's own pump could get me out of a jam till repairs could be effected. Along that thought line do you think there's any chance an OE pump could be located in that tank that's compatible with our systems directly using existing wiring (with auxiliary switch of course) that could function in place of the current stock in-tank setup on our trucks now? Are you running yours that way now or did I misunderstand that it's only a spare that pumps into the original tank?

That was my thought as well. I do not have it plumbed that way, as that would not be easy to do and require additional transfer valves. The whole thing would get pretty complex. I figured in a pinch that I could reroute the line and attach it to the main fuel line. At least the option is there if I need it in the middle of nowhere.

I am going to merge this with the fuel tank thread.

One further question. Is that tank out of a 2.6 or a 2.8 engine trooper? Or are they the same tank? I ask because car-part.com calls them out that way.

I don't know. My guess is that they are the same?

[roadrunner]

More food for thought for you HJ. While looking on car-part.com I noticed one listing for a "shield only". Perhaps something worth consideration given your propensity for off-roading in rocky areas. Tight as your rear tank looks to be mounted might not be adaptable to your truck though. Just musing here.

[HenryJ]

More food for thought for you HJ. While looking on car-part.com I noticed one listing for a "shield only". Perhaps something worth consideration given your propensity for off-roading in rocky areas. Tight as your rear tank looks to be mounted might not be adaptable to your truck though. Just musing here.

Did you look all the way to the bottom of my mod page? Mine did come with and does have a shield installed Thanks for thinking about me though

[roadrunner]

Duh!!! Even more info there than I first thought. Don't know how I missed that one!