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15 or 20 gal fuel tank?

5222 Views 6 Replies 2 Participants Last post by  muddog
ok so i took a rough measurement of the tank and calculated the cubic inches and converted to cubic feet. there are 7.418 gallons in one cubic foot. i came up with around 20 gallons although this was an approx measurement being that the tank is on top of the skid plate. i ran an experiment subtracting only one inch from the three dims and works out to 15 gal.

also one of the corners is dog eared.

BUT the tank is plastic! does anyone have a plastic fuel tank? could this be the tell-tail sign of it being the optional 20 gal?

just don't want to carry gas and purposely run out or find it taking more than 15 gals at the station.


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I don't know. My 85 does have the plastic 20 gal. but I don't know for sure what you could get on the YJ.

"No officer I haven't been drinking , Thats just how my Jeep drives"
My 85 CJ7 has a 20 gallon tank, it is steel. Our 78 CJ7 has a 15 gallon tank. The 20 gallon tank hangs down a little farther.
This & that a new skid plate is harder to find & more expensive are the only two disadvantages I see to it. (it is rather ironic that our
78 CJ7 with the 304V8 has the 15 gal tank while the 85 with 258I6 has the 20 gal tank)

'78 CJ7 304, rust, inspected!/wwwthreads_images/icons/crazy.gif
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thanks guys!
being a new rig i was not sure the fuel gauge was accurate. you know-murphy's law! interesting that dirtydog has a plastic also. i was surprised when i saw a plastic tank! oh these jeeps.


My 84 has the 20 gallon plastic tank...and I LIKE plastic. Especially have I re-designed the skid plate on it and reduced the capacity by about 10 gallons. But no leaks, and once I had it apart, it went back to its original shape. Of course it won't happen again...I made a new shield out of 10 gauge plate steel. I can now jack up the back of the jeep with it.

John......southern CA
84CJ7, 3"lift, 32"BFG, 4.10's, ARB Locker, Solid Axle's, Durabak
The YJ's all have the same size gas tank. The optional 20 gallon tank only has a shorter filler vent. I converted my 15 gallon tank to a 20 gallon tank in about 20minutes. There are a couple of websites that detail this conversion (Obi-Wan's jeep page--don't know the url).

If the tanks are the same size then how can there be 2 different volumes?

87 wrangler - 258
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