So what's your gas mileage? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

bobs409 · 06-16-2003, 08:05 AM

I finally got my speedometer set accurately (took 6 years to get myself to do it)

so I thought I'd enjoy the fruits of my labor and check the gas mileage. How's 16 miles to the gallon! Not too bad for an old truck.

Mine is a 1969 C-10 short stepside with a 74 350/2 bbl and turbo 350. Rear gears are 3.73 and the truck weighs 3700lbs.

I could probably have squeezed a bit more out of it but a few irritating drivers made me get on it 2-3 times during this tank full!

:p

This is around town mainly. Im afraid to check the big highways as I know the 3.73's would kill mileage.

So hows yours? (remember, accurate speedometer first)

71Chev · 06-16-2003, 08:11 AM

Speedo dead on. 18.4mpg average on highway and city. Running between 30-80 mph.

JimKshortstep4x4 · 06-16-2003, 08:28 AM

We get 15-16 miles to the gallon on the highway at 70 mph. 14
around town. Loaded or empty does not seem to matter.

Jim

cleatussnow · 06-16-2003, 08:34 AM

Ok,

454, Th400, 411's, and 35's...

I got 11 keeping it in the primarys for 150 miles. Around town 7-9

cleatus

*Gee_Emm* · 06-16-2003, 09:17 AM

Mine seems to use gas even if its not running, and when it is running it uses even more. Plus I got 4:10's

71GMC_3/4T · 06-16-2003, 10:01 AM

After keeping all the receipts with the miles written on them, I put them into excel. Hovering in the 10 to 11 mpg range consistantly. The pipes sound best when I'm standin' on it!!!

69sixpackbee · 06-16-2003, 12:04 PM

I get 10 with the the 402.

ABHaulR · 06-16-2003, 12:13 PM

Oh Boy! How about 8 mpg in the city or on the highway, rolling tall or pulling a long haul.

But then again, it's 337,000 original miles on an mildly tired 350.
We currently have 4:11's. on 40" Tires.

72chevyLWB · 06-16-2003, 12:40 PM

15.4 going 65 and 12.5 going between 80-100mph. 3.73's w/ overdrive.

Ackattack · 06-16-2003, 12:51 PM

About 11 mpg. 3.08 gears, fresh rebuild, not to big of a cam. I gotta rejet this edelbrock carb, I think I could squeeze out a few more based on what everyone else is getting.

jayssunm · 06-16-2003, 02:04 PM

How do I check the accuracy of my speedometer? Would love to know (I think) what my gallons per mile is.

1972ChevyGuy · 06-16-2003, 02:24 PM

/me nods and uses 5 gallons per run on the 1/4 :grin: The ole 350 gets around 10, and im poor, so it dont get out much

*Gee_Emm* · 06-17-2003, 10:46 PM

What kind of mileage can I expect out of a 6 cylinder 250?

gmc67swb · 06-17-2003, 10:52 PM

MINE GETS ABOUT 20MPG. 3.54'S OUT BACK. TREMEC 5-SPEED AND TBI ON A 327

cruzn72 · 06-18-2003, 12:29 AM

I am lucky if I get 7-8 in town. The 4.11's and aftermarket stall do not help matters any. I have not driven it on the freeway since I got done working on it. It will probably rattle apart.

71402BB · 06-18-2003, 12:43 AM

Just started up my freashy rebuilt 402 tonight so I'm not sure what I'll get for mileage or what to expect.... But I'm really hoping for 10 mpg...

mtdave2 · 06-18-2003, 01:09 AM

poor mans way of checking speed go. go up to the highway and put it at 60mph. get the passenger to start a stopwatch when you pass a mile marker.. keep it at 60 till you hit the next marker.. should be 60 seconds.

i seem to be getting 10 or so with my 350 auto trans..373s... i did get 17 when i moved to texas .. that was on the highway at 50.. wish i could get that all the time.

bouncytruck · 06-18-2003, 11:48 AM

My speedo is way, way off. But I'm estimating in the 6-8 mpg. My carb is a little messed up though. I've got another doner that I'm going to rebuild and see if it works better.

Old Chevy · 06-18-2003, 12:08 PM

Jayssun, check your speedo against a portable gps.

Cheers

Richard

Project1970 · 06-18-2003, 12:26 PM

Quote:

Originally posted by gmc67swb
MINE GETS ABOUT 20MPG. 3.54'S OUT BACK. TREMEC 5-SPEED AND TBI ON A 327

How much of a difference did the TBI make?

GMC JUNKIE TOO · 06-18-2003, 01:23 PM

I get about 8 mpg with my non stock 327

with a 2500 stall verter and factory 4:?? gears

Gee_Emm I got 11 out of my 250 with same gears

gmc67swb · 06-18-2003, 10:08 PM

Quote:

Originally posted by Project1970

How much of a difference did the TBI make?

MAYBE A MPG OR TWO...THE BEST THING IS THE START UP AND DRIVE AWAY. NO TIME OR GAS WASTED ON WARM UP. BEFORE IT TOOK A LITTLE PEDAL EFFORT ON COLD START.

lukecp · 06-18-2003, 11:04 PM

13 mpg going 75 on the highway. 350/350/3.07 gears. It would proably get 14-15 if i were to keep my foot out of it and drive 60-65 mph.

I don't have to warm up my truck very much at all. I have my electric choke tuned pretty good, so i pretty much start it up, put it in gear and drive off. It may die every now and then if it has only run for 10 seconds, but usually goes just fine. From my experience, electric chokes work great, but the old divorced choke Q-jet i had worked like crap, and i had to sit around and warm it up.

Roberty · 06-19-2003, 12:24 AM

Quote:

Originally posted by Gee_Emm
What kind of mileage can I expect out of a 6 cylinder 250?

The 6 banger trucks don't get any better gas mileage than a stock 350 V8 powered one gets. This may be due to the way that they are geared but my dad had a 72 with the 250 inline 6 and 3 speed straight shift that he bought new. It got 12 mpg average and that's from the time it was new to when he sold it several years ago. I'm not sure what the rear gear ratio was - whatever the default ratio GM was putting in them back then with this engine/tranny combo. My 71 with it's 350 4 barrel/turbo 350 combo gets around 14 mpg average.
My advice is to go with the V8 Gee_Emm.
Robert

jhow66 · 06-19-2003, 01:02 AM

Gas mileage!-what's that? (3.07 with a 502)

06-16-2003, 08:05 AM	#1
bobs409 1969 Custom 30 wrecker Join Date: Sep 2001 Location: Pottsville, Pa Posts: 2,611	So what's your gas mileage? I finally got my speedometer set accurately (took 6 years to get myself to do it) so I thought I'd enjoy the fruits of my labor and check the gas mileage. How's 16 miles to the gallon! Not too bad for an old truck. Mine is a 1969 C-10 short stepside with a 74 350/2 bbl and turbo 350. Rear gears are 3.73 and the truck weighs 3700lbs. I could probably have squeezed a bit more out of it but a few irritating drivers made me get on it 2-3 times during this tank full! :p This is around town mainly. Im afraid to check the big highways as I know the 3.73's would kill mileage. So hows yours? (remember, accurate speedometer first) __________________ Bob 63 Impala 283/PG/3.36 (under restoration) 66 Impala 327/PG/3.36 66 Chevelle SS 409/M22/3.55 69 Chevelle 307/PG/3.08 (future restoration) 69 C10 short stepside 454/TH350/3.73 69 Custom 30 tow truck 350/4 spd/4.10 (resto done, CRUISIN TIME!) 71 Cheyenne 20 fleetside 350/4 spd/4.10 71 Chevelle 6/PG/3.08 72 Chevelle 454/M21/4.10

06-16-2003, 08:11 AM	#2
71Chev Senior Member Join Date: Dec 2000 Location: Indiana Posts: 3,074	Speedo dead on. 18.4mpg average on highway and city. Running between 30-80 mph. __________________ 71 Chevy CST Long Fleet 350/350/3.07 leaf rear.

06-16-2003, 08:34 AM	#4
cleatussnow Registered User Join Date: Jun 2002 Location: Pleasanton, CA Posts: 162	Ok, 454, Th400, 411's, and 35's... I got 11 keeping it in the primarys for 150 miles. Around town 7-9 cleatus __________________ "What we are dealin' with here is a complete lack of respect for the law...." Beuford T. Justice

06-16-2003, 10:01 AM	#6
71GMC_3/4T Weapons Of Construction Join Date: Apr 2000 Location: Colorado, USA Posts: 1,095	After keeping all the receipts with the miles written on them, I put them into excel. Hovering in the 10 to 11 mpg range consistantly. The pipes sound best when I'm standin' on it!!! __________________ 1971 GMC 2500, 402/TH400 4.10 Daily Driver Lafayette, CO

06-16-2003, 12:13 PM	#8
ABHaulR Registered User Join Date: Jun 2003 Location: West Valley City, Ut Posts: 311	Oh Boy! How about 8 mpg in the city or on the highway, rolling tall or pulling a long haul. But then again, it's 337,000 original miles on an mildly tired 350. We currently have 4:11's. on 40" Tires. Attached Images

06-16-2003, 08:28 AM	#3
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	We get 15-16 miles to the gallon on the highway at 70 mph. 14 around town. Loaded or empty does not seem to matter. Jim

06-16-2003, 09:17 AM	#5
Gee_Emm Account Suspended Join Date: Sep 2000 Posts: 4,002	Mine seems to use gas even if its not running, and when it is running it uses even more. Plus I got 4:10's

06-16-2003, 12:04 PM	#7
69sixpackbee Registered User Join Date: Jan 2001 Location: Sabinal, Texas Posts: 1,706	I get 10 with the the 402.

06-16-2003, 12:40 PM	#9
72chevyLWB Got 20's???? Join Date: Oct 2001 Location: Aberdeen SD Posts: 1,451	15.4 going 65 and 12.5 going between 80-100mph. 3.73's w/ overdrive. __________________ 99 Silverado Ex-Cab 2wd, Bagged&WhippleCharged 02 Sierra Ex-Cab 4wd 2500 HD The 72 went down the road.

06-16-2003, 12:51 PM	#10
Ackattack Senior Member Join Date: Aug 2002 Location: Valley Center KS Posts: 3,525	About 11 mpg. 3.08 gears, fresh rebuild, not to big of a cam. I gotta rejet this edelbrock carb, I think I could squeeze out a few more based on what everyone else is getting. __________________ Project Bruiser: 68 Pro-Touring C-10 5.3L / 4L60E Project Ironhide: 97 GMC Crew Cab 4x4 Cummins SOLD: '69 GMC 1/2T SWB TBI'd: Project No Buck Assembly Manual Index Sign up Thread!!! Factory Service Manual Index

06-16-2003, 02:04 PM	#11
jayssunm Registered User Join Date: Jan 2003 Location: San Diego, CA Posts: 98	How do I check the accuracy of my speedometer? Would love to know (I think) what my gallons per mile is. __________________ 67 Fleetside Shortie, small window, slip & slide tranny Upgrades--small block, tilt column, disc 5 lug conversion (front and rear), Future Projects--suburban gas tank under the bed, rear roll pan, better gas mileage (currently about 6-10 MPG)

06-16-2003, 02:24 PM	#12
1972ChevyGuy Registered User Join Date: Nov 2002 Location: Kannapolis, NC Posts: 552	/me nods and uses 5 gallons per run on the 1/4 :grin: The ole 350 gets around 10, and im poor, so it dont get out much

06-17-2003, 10:46 PM	#13
Gee_Emm Account Suspended Join Date: Sep 2000 Posts: 4,002	What kind of mileage can I expect out of a 6 cylinder 250?

06-17-2003, 10:52 PM	#14
gmc67swb Registered User Join Date: Feb 2003 Location: Mesquite, Tx Posts: 396	MINE GETS ABOUT 20MPG. 3.54'S OUT BACK. TREMEC 5-SPEED AND TBI ON A 327 __________________ GM 330HP/350, Magnuson 122HH, Tremec TKO 5spd

06-18-2003, 12:29 AM	#15
cruzn72 Registered User Join Date: Mar 2003 Posts: 99	I am lucky if I get 7-8 in town. The 4.11's and aftermarket stall do not help matters any. I have not driven it on the freeway since I got done working on it. It will probably rattle apart. __________________ http://photos.yahoo.com/cruzn72@pacbell.net



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06-18-2003, 12:43 AM	#16
71402BB now thats a true COON DOG Join Date: Nov 2000 Location: Franconia, NH Posts: 1,977	Just started up my freashy rebuilt 402 tonight so I'm not sure what I'll get for mileage or what to expect.... But I'm really hoping for 10 mpg... __________________ current project 67 402BB stout th350 3.08's with a locker. Plan on tubs 18.5's out back! (thanks Burnsman!) 71 SWB Stepside, was a 250, now is a 402 Big Block with 4 speed and 3.73's ( was crushed by a tree, bed sold, motor pulled) was my first truck!... oh well... 72 LWB 4x4 350 4-speed 3.08's posi wearing army olive drab green (SOLD!) 68 BURB 50TH LOOKALIKE work in progress, soon to have 250-I6 with a 3-speed on the tree 4.11's and posi ( currently sitting in back yard tarped awaiting time, $$$, and lots of love!) 67 1 TON- work truck 396 sm 420 4-speed, flat bed 4.57 gears "big red" (my first landscape truck, very rusty and crusty! but still gets the job done when needed!)

06-18-2003, 01:09 AM	#17
mtdave2 newly minted old timer Join Date: Dec 1999 Location: Hudson WI Posts: 3,508	poor mans way of checking speed go. go up to the highway and put it at 60mph. get the passenger to start a stopwatch when you pass a mile marker.. keep it at 60 till you hit the next marker.. should be 60 seconds. i seem to be getting 10 or so with my 350 auto trans..373s... i did get 17 when i moved to texas .. that was on the highway at 50.. wish i could get that all the time. __________________ ____________________________________________ 72 c20 longhorn 65k org miles and counting! 69 k10 Suburban

06-18-2003, 11:48 AM	#18
bouncytruck SKINNY TIRES RULE! Join Date: Sep 2001 Location: Bothell, WA Posts: 11,049	My speedo is way, way off. But I'm estimating in the 6-8 mpg. My carb is a little messed up though. I've got another doner that I'm going to rebuild and see if it works better. __________________ bouncytruck 1972 K5 The Hauler 1994 K1500 Suburban The Daily2010 Kia Soul Wife's Ride2014 Fiat 500L

06-18-2003, 12:08 PM	#19
Old Chevy Registered User Join Date: Jan 2000 Location: Tulsa, Oklahoma Posts: 498	Jayssun, check your speedo against a portable gps. Cheers Richard __________________ Broken Arrow, OK. 1977 Corvette, ZZ4 Crate, new interior, new suspension, new driveline, you get the picture, (new project / daily driver)

06-18-2003, 01:23 PM	#21
GMC JUNKIE TOO THE QUICKER FIXERUPER Join Date: Jul 2002 Location: Ok Posts: 615	I get about 8 mpg with my non stock 327 with a 2500 stall verter and factory 4:?? gears Gee_Emm I got 11 out of my 250 with same gears

06-18-2003, 11:04 PM	#23
lukecp Formerly yellow72custom Join Date: May 2001 Location: Austin, TX Posts: 7,531	13 mpg going 75 on the highway. 350/350/3.07 gears. It would proably get 14-15 if i were to keep my foot out of it and drive 60-65 mph. I don't have to warm up my truck very much at all. I have my electric choke tuned pretty good, so i pretty much start it up, put it in gear and drive off. It may die every now and then if it has only run for 10 seconds, but usually goes just fine. From my experience, electric chokes work great, but the old divorced choke Q-jet i had worked like crap, and i had to sit around and warm it up. __________________ '72 Chevy C10 Mild 350/TH350/3.07. Ochre/White. Old high school ride. '70 GMC C2500 '62 327 4bbl/SM465/4.56-geared Dana 60. White/White. Project or parts truck. '97 Saturn SL DD. 1.9/5-speed. 40+ highway mpg

06-19-2003, 01:02 AM	#25
jhow66 Registered User Join Date: Jun 2002 Location: Knoxville Tenn. Posts: 3,058	Gas mileage!-what's that? (3.07 with a 502) __________________ 56 Chevy Bel-Air 2dr. HT (purchased new) 71 Chevy Cheyenne SWB PU (502HO) 65 GMC short bed step--work in progress and my gofer

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