how many gallons of gas do our tanks hold - The 1947 - Present Chevrolet & GMC Truck Message Board Network

burke117 · 11-21-2009, 06:30 PM

how many gallons of gas do our tanks hold?

72chevyk10 · 11-21-2009, 06:45 PM

the in cab tank i got is about 16 gallons (+/- a little) most ive ever been able to put in it was 12 gallons and that put the gauge waaaaaay over full

leh72super1500 · 11-21-2009, 06:49 PM

The capacities section in my owners manual for my 72 GMC 1500 says it is 20.2 US gallons for C/K 15 Cabs. For C25/35 Cabs it is 21.0 US gallons. Hope this helps

**Stocker** · 11-21-2009, 07:05 PM

Counting my Travel Tanks, I have put in just over 50 gallons at one stop.

But yeah, something over 20 in the tank behind the seat....

burke117 · 11-21-2009, 08:32 PM

thanks guys.

Mayo · 11-21-2009, 08:54 PM

I used to fill mine all the way up until the pump shut off, but then sometimes when taking turns some gas would spill out. I can't remember, but if I put either 14 or 17 gallons in it the gauge reads full.

unclewatts · 11-21-2009, 09:58 PM

According to the LMC Truck catalog, a stock behind-the-seat tank holds 20 gallons. whether this is true or not, I don't know. Maybe one of our members with a proper GM spec sheet can answer this question for sure.

Longhorn Man · 11-23-2009, 01:35 AM

20 gallons is what all the books say, and what every truck I've ever owned had in it.
However, there's enough ppl on here saying 15 - 17 gallons, that they had to installl smaller ones for one reason or another.

**special-K** · 11-23-2009, 06:13 AM

I`ve always gone on the 21 gallon assumption.I`ve never run one dry,but have put 20+ gallons in many a time.I think it`s odd that GMC would use a slightly smaller tank in the 1500s than what they used in 2500/3500s?Why would they do that?

**'68OrangeSunshine** · 11-23-2009, 09:13 AM

I've gotten 22 gallons into the in-cab tank in my '68 C/10. The under-belly tank on my '71 Jimmy [K/5] is supposed to be 20, but it seems like it only takes 17 or 18. I wonder if the tanks got smaller when they had to add emissions stuff?

GOPAPA · 11-23-2009, 10:54 AM

Of all the different quotes on how much these tanks hold makes me wonder even more about if the gas pumps are even close to accurate for gallons and tenths ..
I am going with the 20 gal as the book says ,,but I bet it is not exactly 20 gal ,,just close.

chevy_mike · 11-23-2009, 11:59 AM

Remember, 20 gallons is for a Dry tank. Most people don't show up to the gas station with a completely dry tank.

**leddzepp** · 11-23-2009, 12:59 PM

All three behind the seat tanks I have had only held around 15 gals.

69GMCLonghorn · 11-23-2009, 01:32 PM

I always thought they were 18 gallons... I've run mine until the gauge was on Empty and could only shove about 17 1/2 gallons in it. Maybe I had more left in it than I thought.

Longhorn Man · 11-23-2009, 06:27 PM

3 trucks owned here;
69 1/2 ton 305 V6 short/fleet 2 wheel drive
70 3/4 ton 350 longhorn 2 wheel drive
70 one ton 350 longhorn 2 wheel drive

All 3 had 20+ gallon tanks.
I drove to the gas station once and put 21.75 gallons in the C/20 longhorn.
You can bet the pumps are pretty accurate on weights and measures... the gas stations make so little per gallon in profits and the fines are so huge for 'tampering' with the pumps that it just isn't worth it.

69GMCLonghorn · 11-23-2009, 06:45 PM

Quote:

Originally Posted by Longhorn Man

3 trucks owned here;
69 1/2 ton 305 V6 short/fleet 2 wheel drive
70 3/4 ton 350 longhorn 2 wheel drive
70 one ton 350 longhorn 2 wheel drive

All 3 had 20+ gallon tanks.
I drove to the gas station once and put 21.75 gallons in the C/20 longhorn.
You can bet the pumps are pretty accurate on weights and measures... the gas stations make so little per gallon in profits and the fines are so huge for 'tampering' with the pumps that it just isn't worth it.

I'm guessing I had more in my tank than I thought. But I've never been one to push it when it's getting down to empty.

11-21-2009, 06:30 PM	#1
burke117 Registered User Join Date: Dec 2007 Location: magna, utah Posts: 108	how many gallons of gas do our tanks hold how many gallons of gas do our tanks hold?

11-21-2009, 06:49 PM	#3
leh72super1500 GMC with Blue Plaid Join Date: Oct 2009 Location: Langdon, Alberta Posts: 139	Re: how many gallons of gas do our tanks hold The capacities section in my owners manual for my 72 GMC 1500 says it is 20.2 US gallons for C/K 15 Cabs. For C25/35 Cabs it is 21.0 US gallons. Hope this helps __________________ Current: 1972 GMC Super Custom 1500 402 < 73K Orig MI 2015 GMC Canyon SLT(Daily Driver) Previous: 2008 Chevrolet Colorado LT 2.9L I4 1988 Chevrolet Suburban Silverado 10 350 < 60K Orig MI 1984 GMC S-15 2.8L V6 1976 GMC Sierra Classic 2500 Camper Special 350 1980 GMC High Sierra 3500 Dually 350 4spd 1974 Chevrolet Cheyenne Super 10 Shorty 454 (Was my Dads, I wish I still had it) 1969 GMC 910 250 I6 4spd

11-21-2009, 07:05 PM	#4
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,694	Re: how many gallons of gas do our tanks hold Counting my Travel Tanks, I have put in just over 50 gallons at one stop. But yeah, something over 20 in the tank behind the seat.... __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay Last edited by Stocker; 11-21-2009 at 07:06 PM.

11-21-2009, 08:32 PM	#5
burke117 Registered User Join Date: Dec 2007 Location: magna, utah Posts: 108	Re: how many gallons of gas do our tanks hold thanks guys.

11-21-2009, 08:54 PM	#6
Mayo Cool Truck Join Date: Dec 2008 Location: Bowie,MD Posts: 1,869	Re: how many gallons of gas do our tanks hold I used to fill mine all the way up until the pump shut off, but then sometimes when taking turns some gas would spill out. I can't remember, but if I put either 14 or 17 gallons in it the gauge reads full. __________________ 1968 Chevrolet C20 Longhorn "Cool Truck" 1937 Chevrolet Pickup - Project Looking for a patina'd 68 50th Anniversary longbed

11-21-2009, 09:58 PM	#7
unclewatts 70 Chevrolet=Obsession Join Date: Jun 2009 Location: nice ca Posts: 1,067	Re: how many gallons of gas do our tanks hold According to the LMC Truck catalog, a stock behind-the-seat tank holds 20 gallons. whether this is true or not, I don't know. Maybe one of our members with a proper GM spec sheet can answer this question for sure. __________________ I'm Just like my truck. Old, Ugly and Grouchy. Except my truck starts easily in the morning and doesn't smoke! IT'S NOT EASY BEING GREEN! -Kermit the frog 1970 Chevrolet C-10 Longbed Stepside : 350, Muncie M20, 3.08 GM corp. positraction Forest green exterior/light green interior(Where all my money goes) 1996 Toyota Corolla (Parts runner)

11-23-2009, 01:35 AM	#8
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: how many gallons of gas do our tanks hold 20 gallons is what all the books say, and what every truck I've ever owned had in it. However, there's enough ppl on here saying 15 - 17 gallons, that they had to installl smaller ones for one reason or another.

11-23-2009, 06:13 AM	#9
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,852	Re: how many gallons of gas do our tanks hold I`ve always gone on the 21 gallon assumption.I`ve never run one dry,but have put 20+ gallons in many a time.I think it`s odd that GMC would use a slightly smaller tank in the 1500s than what they used in 2500/3500s?Why would they do that? __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

11-23-2009, 09:13 AM	#10
'68OrangeSunshine Senior Member Join Date: Feb 2002 Location: Tucson, AZ USA Posts: 7,441	Re: how many gallons of gas do our tanks hold I've gotten 22 gallons into the in-cab tank in my '68 C/10. The under-belly tank on my '71 Jimmy [K/5] is supposed to be 20, but it seems like it only takes 17 or 18. I wonder if the tanks got smaller when they had to add emissions stuff? __________________ Every 25 years I like to rebuild that 292, whether it needs it or not.

11-23-2009, 10:54 AM	#11
GOPAPA Senior Member Join Date: Oct 2007 Location: Nampa Idaho Posts: 7,551	Re: how many gallons of gas do our tanks hold Of all the different quotes on how much these tanks hold makes me wonder even more about if the gas pumps are even close to accurate for gallons and tenths .. I am going with the 20 gal as the book says ,,but I bet it is not exactly 20 gal ,,just close.

11-23-2009, 11:59 AM	#12
chevy_mike Never Ending Projects Join Date: Jul 2006 Location: San Diego, CA Posts: 3,836	Re: how many gallons of gas do our tanks hold Remember, 20 gallons is for a Dry tank. Most people don't show up to the gas station with a completely dry tank. __________________ . 1965 C10 Panel, Tiki Express http://www.67-72chevytrucks.com/vboa...d.php?t=506580 SOLD 1968 Chevy C10, Long, Fleetside, Hot Rod Hauler http://67-72chevytrucks.com/vboard/s...d.php?t=313233 SOLD 1965 Chevy C10, Long, Fleetside, Hot Rod C10 http://67-72chevytrucks.com/vboard/s...d.php?t=415702 SOLD We were given two ears and one mouth for a reason... listen twice as much and speak half as often...

11-23-2009, 12:59 PM	#13
leddzepp Moderator Join Date: May 2007 Location: Southern Cal Posts: 20,022	Re: how many gallons of gas do our tanks hold All three behind the seat tanks I have had only held around 15 gals. __________________ 1972 C/10 Cheyenne Super SWB. Restored, loaded, slammed. 1968 C/10 50th Anniversary LWB. Unrestored, stock, daily driver/work truck. RIP ElJay RIP 67ChevyRedneck RIP Grumpy Old Man RIP FleetsidePaul

11-23-2009, 01:32 PM	#14
69GMCLonghorn Registered User Join Date: Dec 2006 Location: Porter Ranch, CA Posts: 978	Re: how many gallons of gas do our tanks hold I always thought they were 18 gallons... I've run mine until the gauge was on Empty and could only shove about 17 1/2 gallons in it. Maybe I had more left in it than I thought.

11-23-2009, 06:27 PM	#15
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: how many gallons of gas do our tanks hold 3 trucks owned here; 69 1/2 ton 305 V6 short/fleet 2 wheel drive 70 3/4 ton 350 longhorn 2 wheel drive 70 one ton 350 longhorn 2 wheel drive All 3 had 20+ gallon tanks. I drove to the gas station once and put 21.75 gallons in the C/20 longhorn. You can bet the pumps are pretty accurate on weights and measures... the gas stations make so little per gallon in profits and the fines are so huge for 'tampering' with the pumps that it just isn't worth it.

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