How many gallons can you put in your gas tank?

[SirRobyn0]

Our '81 Sierra C15 had the dual 16 gallon tanks. To fill both I would have to get up in the bed and pass the nozzle and hose across, then get out and insert it into the filler. I understand why GM had them on both sides instead of both on one side like the contemporary ferds, but it sure is inconvenient when filling both tanks.

Ok here is a story for you. My Dad bought a 78' K20 in 80'. Since it was the newest vehicle my parents owned, we took it on a lot of trips, three of us in the cab, Dad, Mom and me. Dad bought a canopy for it that he'd put on before these trips, so there was no passing the nozzle from side to side. Keep in mind back then a lot of stations had pretty short hoses, at least around here, and post paid was common. So it would be my job to stand there and hold the nozzle and keep anyone from pulling in as my Dad turned around to fill the other side and if someone came out thinking he was driving off without paying I became his deposit lol.

 

[Ricko1966]

Heres a story and a pic is floating around somewhere, I want a copy of it. A whole bunch of us heading for little sahara to play with our buggies. The shop I was running had parts and service, I grabbed some essentials in case anyone broke down. A gasket set a roll of fuel hose, extra plugs, fuel filter etc. Jimmys burb. Pulling a trailer full of quads and buggies runs out of gas like 2 A.M. in the middle of nowhere. My buggie had a full tank and an electric pump. We hooked the entire roll of fuel hose to my pump, ran it off the side of my trailer onto the road under jimmys burb and in to his fuel filter. Turned on my pump and got him going. Everybody was like who the eff has a whole roll of fuel line with them? I gotta call Billy and find out who has that pic.

 

[HotWheelsBurban]

Ok here is a story for you. My Dad bought a 78' K20 in 80'. Since it was the newest vehicle my parents owned, we took it on a lot of trips, three of us in the cab, Dad, Mom and me. Dad bought a canopy for it that he'd put on before these trips, so there was no passing the nozzle from side to side. Keep in mind back then a lot of stations had pretty short hoses, at least around here, and post paid was common. So it would be my job to stand there and hold the nozzle and keep anyone from pulling in as my Dad turned around to fill the other side and if someone came out thinking he was driving off without paying I became his deposit lol.

Yup we had to do that sometimes. Some stations, as you pointed out, have short hoses. And I remember 3 across or a couple of times, 4 across, the bench seat on a trip. We were all younger and thinner then....

 

[TotalyHucked]

I may or may not have put 16.5 gallons in my 16gal tank a couple times

 

[Turbo4whl]

I can only put 13 gallons in to fill. Is that right or is there a problem with sending units or the gauge?

Other than the gauge bounces a little with the gas sloshing. (There’s a fix for that, some resistor that goes in the dash, there’s a write up on here somewhere about it)

The gauge could have an issue. One thing that it could be, is the resistor on the back of the fuel gauge goes bad. The resistor bolts to the back of the gauge on 2 of the contact studs. What I also found out, GM had used different resistor values to match the different senders.

The example I learned this on, I replaced my large fuel gauge with the combo tach/fuel gauge from a C60. Then the fuel gauge was wrong. I removed the resistor from the original gauge and put it on the C60 combo fuel gauge. Then the small fuel gauge was correct. These GM resistors have a painted color strip, different colors for different values.

Todd, the write up you saw, did they replace the stock resistor with a resistor that had capacitor or some other buffer?

As far as I know, a Blazer or Suburban gauge will have a different resister than a pickup truck.

 

[SirRobyn0]

The gauge could have an issue. One thing that it could be, is the resistor on the back of the fuel gauge goes bad. The resistor bolts to the back of the gauge on 2 of the contact studs. What I also found out, GM had used different resistor values to match the different senders.

The example I learned this on, I replaced my large fuel gauge with the combo tach/fuel gauge from a C60. Then the fuel gauge was wrong. I removed the resistor from the original gauge and put it on the C60 combo fuel gauge. Then the small fuel gauge was correct. These GM resistors have a painted color strip, different colors for different values.

Todd, the write up you saw, did they replace the stock resistor with a resistor that had capacitor or some other buffer?

As far as I know, a Blazer or Suburban gauge will have a different resister than a pickup truck.

As far as I know what you have said is correct. All the truck C/K 10 - 30 will use the same resistor because they have the same sending unit, the C 50's & C60's use a different resistor, the Blazers and Suburban's I think use the same resistor but is different from all the others.

I also want to add that on the trucks some gauge movement is pretty normal when the tank is above a 1/4 and below 3/4 and that's just because they are such long narrow tanks. But it shouldn't be any violent movement of the gauge or anything that makes it hard to tell how much fuel is in the tank.

 

[Keith Seymore]

Your not imaging it you own one! But your truck is a pretty unique configuration and I bet you get a far bit better mileage than most of us!

I don't recall now why I didn't order the dual tanks. I had them on my '80 stepper.

I imagine I was just trying to trim the initial purchase price a little bit. I didn't even have A/C at first (I caught the order and added a/c as soon as I found out I was moving to the DPG.

K

 

[SirRobyn0]

I don't recall now why I didn't order the dual tanks. I had them on my '80 stepper.

I imagine I was just trying to trim the initial purchase price a little bit. I didn't even have A/C at first (I caught the order and added a/c as soon as I found out I was moving to the DPG.

K

Of course I bought my truck used and had different wanted specifications, like I wanted a C/K 20 or 30 but the only option I had to have was A/C.

 

[Grit dog]

@Turbo4whl, it is actually a thread on here. Explains the different colors/ohms. And as I recall, they are still available from some corvette parts site, or at least they were years ago. Lol
On the 86, it’s pretty low on the to do list. Especially since the gauge/senders actually work as well as they do.
A little bobbing of the gas gauge just adds character.

 

[Wallace6]

Anybody try a suburban tank in the spare tire area?

 

[Sgt Gus]

Two dual 20's. On 87 3/4 ton.
Plenty of room in the bed for 3rd aux tank. Paint it ECO green. Stencil H2O on it.
OK, I'm done.

 

[SirRobyn0]

Anybody try a suburban tank in the spare tire area?

It's been done. It's actually a very common thing for folks to do who want to eliminate the saddle tanks, search the forums for it. But I will say I did consider adding one as a third tank 31 gallons. Total 61 gallons, leaving 3 gallons in each tank that's 52 gallons @ 14 per-gallon that's 728 miles! @ 12 mpg 624! Even at 10 that's 520! But it's also an added 186lbs in fuel weight behind the axle, the worst place to haul a load.

 

[ford]

Sadly just a 20gal for my EFI conversion. Somehow i need to get more fuel capacity as this will become my overlanding vehicle. Not sure if i want to do a dual tank setup and move my remote battery mount or do some type of backup tank in the bed.

 

[SquareRoot]

Interesting thread.

I have a different approach I'll throw out there for anyone interested. After the EFI swap, I needed to change the fuel supply system. However, the key ingredient in my system is the Dakota Digital (DD) gauges.
I put in new Spectra 20 gallon tanks (dual tanks) for an 87. New Spectra sending units for an 87. AC Delco EPI 381 pumps. With both tanks completely dry, I used the calibrate feature of the DD to set the fuel level on the gauge to the amount of fuel in the tanks. I poured in exactly 5 gallons and set it to the 1/4 tank mark. Added another 5 gallons and set to 1/2 mark. Repeat for 3/4 & full. Then I continued to fill each tank a gallon at a time until it ran out the neck. Both sides were an additional 3 gallons.

I know exactly how much fuel is in each tank at any time. Better yet, the DD allow you to add a low fuel warning light. I set the warning to come on when the tank level reaches 10%. It's a beautiful setup. It also comes in handy for tracking engine hours and lets you set oil change reminders. It's like the best of everything. And we all drank beer and learned things.

 

[SquareRoot]

Anybody try a suburban tank in the spare tire area?

Yes. The 40 gallon version. Hung way to low and interfered with the exhaust.