What's your fuel Mileage? - Page 3 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

TwoFiftyShifter · 08-09-2009, 09:22 PM

What do you think my new rig will pull mpg? 87 350TBI 3/4ton, sm465 creeper box and either 3.73 or 4.10 gears..... at 60-65mph on the highway. Can I hope for 12-14?

1985-GMC · 08-09-2009, 09:48 PM

1983 single cab dually, 454 hiped up a little, stock quadrajunk, sm465, 4.10 gears, manifolds, 2 1/2" duals, 3" tips, 9" glass packs, CB radio

7-8 in the hill country
13 if i go easy on it

manimal · 08-09-2009, 10:23 PM

Yesterday I got 13.5 @ 70mph with the air on in my '84 crewcab w/454/TH400/14blt 3.73 and 265x75x16's...
-Lance

thirdstreettito · 08-09-2009, 11:21 PM

So far I win with best mileage.

Keith Seymore · 08-10-2009, 07:09 AM

Quote:

Originally Posted by thirdstreettito

So far I win with best mileage.

Quote:

Originally Posted by INSIDIOUS '86

not so fast third street!

i get 17mpg city depending on how heavy my foot is and 20mpg highway
i have 86 scottsdale with 305/700r4 and 2:73 gears. goin nowere fast in this thing

Nuh-uh guys - I said 22 mph with my little V6 and manual overdrive!

INSIDIOUS '86 · 08-10-2009, 06:08 AM

not so fast third street!

i get 17mpg city depending on how heavy my foot is and 20mpg highway
i have 86 scottsdale with 305/700r4 and 2:73 gears. goin nowere fast in this thing

GMC91 · 08-10-2009, 06:42 AM

83 305 HO with a screwed up 700R4 and Holley 600 4-barrel. Best is 15 MPG mostly 12-13 MPG cause my right foot.

D13 · 08-10-2009, 07:51 AM

And you better check out my diesel numbers! Get 22mpg with bad pump and heavy foot LOL! Taking it easy is 24mpg no problemo.

Next build is 82 1/2 ton 3.08's 250L6 with A-833 like Keith's. I drive like a little old lady so I bet I can get 22mpg out of it! If not than I'll swap in my 194 Nova motor and toss on TBI. That'll get ya!

*78 Chevyrado* · 08-10-2009, 08:45 AM

I was getting around 15-16mpg Hwy before they imposed crap E10 gas on us, now I get 10-12mpg HWY. The truck never runs quite right now since it has no computer and seems to need to be recalibrated slightly for each tank of gas, since the gas is never the same from tank to tank.

78 c20, 350sb th400 3.73 rear end. 4950lbs.

I don't list what I used to get in my '87 since everybody always calls BS.

*C-10 simplex* · 08-10-2009, 10:35 AM

About 16ish mostly highway driving.

But for anyone serious about mpg, please read my very drawn out, thourough, anal, and scientific research thread on mpg:

http://forum.73-87chevytrucks.com/sm...p?topic=8474.0

P.S., i feel that tires could make all the difference in the world; i would be looking at michelin X.

Robert1970C20rstbukt · 08-10-2009, 04:24 PM

1984 Chevy regular cab flatbed dually, 454 with 2 1/2" dual exhaust and 12" chamber glasspacks(nice and LOUD

), stock air breather and Qjet, SM465, 4.10 gears, 235/85/16 rubber at 60psi. Right now I get about 6-7 in town and highway is close to 14, that's doin' around 50-55. Any higher and the gas gauge moves to the left real quick.

thirdstreettito · 08-10-2009, 10:13 PM

My diesel gets 22hwy, but I was doing 75-90, if I did 60-70 I'd probably get 25 easy.

Bow Tie Scottie · 08-10-2009, 10:27 PM

Why would you ask? O.K., my 86 gets about an average of 8 to 10. BTW, I hope the feds aren't looking.

**nlped** · 08-14-2009, 02:08 PM

I average 14-16 mpg with mixed driving. I have gotten 18 mpg once on a road trip running 72 in the fall w/ no air running. '87 GMC 2wd w/ 350 TBI, 700r4, & 3.42 rear. But I had the stock 2.73 rearend when I got the 18 mpg.

Cheers,

Ed

*Stitch* · 08-14-2009, 09:36 PM

I get 26 city/22 highway

1/2ton swb 2wd, 6.2 diesel, 700r4, 3.42 gear...

and the injection pump is turned up some...go figure

KQQL IT · 08-15-2009, 04:42 PM

Hmmm when the gauge says 1/8th its time for more gas... I thought it was more about smiles per mile

Manbearpig · 08-15-2009, 05:45 PM

About 5MPG in the K5

14 City/17 Highway in the 04 Sierra

rome704 · 08-17-2009, 02:47 PM

50 feet 2 da gallon lol

more like 10 mpg

Sniper X · 08-17-2009, 02:57 PM

When I do get the clutch in the 74, Ill bet i get about the same as the big block! The 350 never was a great gas mileage monster in a C20...even with the 4 speed.

texastruckjunky · 08-18-2009, 02:04 AM

mine has a 454 with .505 lift cam. 1 over the RV cam. Headers 2 1/2 exhaust w/flowmasters and a factory Holly spreadbore carb. In town about 6-8 driving like grandpa. Hwy 9-11 55-60.

08-09-2009, 09:22 PM	#1
TwoFiftyShifter Registered User Join Date: Nov 2008 Location: Gwinnett GA Posts: 1,803	Re: What's your fuel Mileage? What do you think my new rig will pull mpg? 87 350TBI 3/4ton, sm465 creeper box and either 3.73 or 4.10 gears..... at 60-65mph on the highway. Can I hope for 12-14? __________________ 1982 K10 SWB 1987 V20 - Sold - Doh!

08-09-2009, 09:48 PM	#2
1985-GMC Chevy Enthusiast Join Date: Jul 2009 Location: Canyon Lake Texas Posts: 2,024	Re: What's your fuel Mileage? 1983 single cab dually, 454 hiped up a little, stock quadrajunk, sm465, 4.10 gears, manifolds, 2 1/2" duals, 3" tips, 9" glass packs, CB radio 7-8 in the hill country 13 if i go easy on it

08-09-2009, 10:23 PM	#3
manimal Registered User Join Date: Oct 2006 Location: Southern Kalifornia Posts: 3,066	Re: What's your fuel Mileage? Yesterday I got 13.5 @ 70mph with the air on in my '84 crewcab w/454/TH400/14blt 3.73 and 265x75x16's... -Lance __________________ ------------------------------------------------------ -Lance 2000 Chevy C2500, 5.7, 4L80e 1999 Suburban K2500, 7.4, 4L80e 1980 Camaro..son's car...PROJECT

08-09-2009, 11:21 PM	#4
thirdstreettito Resident of Here Join Date: May 2008 Location: Wesley Chapel, FL, USA Posts: 7,716	Re: What's your fuel Mileage? So far I win with best mileage. __________________ ~Bradley~ 2004 Black GTO LS2/T56 too much to list Miss having a truck

08-10-2009, 06:08 AM	#6
INSIDIOUS '86 Registered User Join Date: Jul 2009 Location: washington Posts: 4,178	Re: What's your fuel Mileage? not so fast third street! i get 17mpg city depending on how heavy my foot is and 20mpg highway i have 86 scottsdale with 305/700r4 and 2:73 gears. goin nowere fast in this thing

08-10-2009, 06:42 AM	#7
GMC91 Always trouble Join Date: Jul 2009 Location: Hartsellle, Al Posts: 1,111	Re: What's your fuel Mileage? 83 305 HO with a screwed up 700R4 and Holley 600 4-barrel. Best is 15 MPG mostly 12-13 MPG cause my right foot. __________________ 91 Silverado Regular cab, 2wd, swb-project truck 97 Silverado Extended cab, 2wd, swb-driver

08-10-2009, 07:51 AM	#8
D13 Registered User Join Date: Feb 2007 Location: Memphis MI Posts: 1,851	Re: What's your fuel Mileage? And you better check out my diesel numbers! Get 22mpg with bad pump and heavy foot LOL! Taking it easy is 24mpg no problemo. Next build is 82 1/2 ton 3.08's 250L6 with A-833 like Keith's. I drive like a little old lady so I bet I can get 22mpg out of it! If not than I'll swap in my 194 Nova motor and toss on TBI. That'll get ya! __________________ 1987 2 ton 1982 250/TH350 beater in progress Dad's 1981 3/4 L6 3 on tree posi and no options, awaiting restoration or scrapping Plus a mess o' tractors

08-10-2009, 08:45 AM	#9
78 Chevyrado Account Suspended Join Date: Dec 2007 Location: Unnapreciative, Trollville Posts: 2,079	Re: What's your fuel Mileage? I was getting around 15-16mpg Hwy before they imposed crap E10 gas on us, now I get 10-12mpg HWY. The truck never runs quite right now since it has no computer and seems to need to be recalibrated slightly for each tank of gas, since the gas is never the same from tank to tank. 78 c20, 350sb th400 3.73 rear end. 4950lbs. I don't list what I used to get in my '87 since everybody always calls BS. Last edited by 78 Chevyrado; 08-10-2009 at 06:03 PM.

08-10-2009, 10:35 AM	#10
C-10 simplex Account Suspended Join Date: Dec 2008 Location: indisclosed Posts: 1,515	Re: What's your fuel Mileage? About 16ish mostly highway driving. But for anyone serious about mpg, please read my very drawn out, thourough, anal, and scientific research thread on mpg: http://forum.73-87chevytrucks.com/sm...p?topic=8474.0 P.S., i feel that tires could make all the difference in the world; i would be looking at michelin X.

08-10-2009, 04:24 PM	#11
Robert1970C20rstbukt Registered User Join Date: Jun 2004 Location: Beeville, Texas Posts: 1,943	Re: What's your fuel Mileage? 1984 Chevy regular cab flatbed dually, 454 with 2 1/2" dual exhaust and 12" chamber glasspacks(nice and LOUD ), stock air breather and Qjet, SM465, 4.10 gears, 235/85/16 rubber at 60psi. Right now I get about 6-7 in town and highway is close to 14, that's doin' around 50-55. Any higher and the gas gauge moves to the left real quick. __________________ RJD 1984 Chevrolet C30 welding truck 454/SM465 1977 GMC C15 pickup 350/TH350 1970 Chevrolet C20 pickup 350/TH400 1970 Chevrolet K20 Suburban 454/TH350 1969 GMC 8500 478M V6/5 spd winch truck

08-10-2009, 10:13 PM	#12
thirdstreettito Resident of Here Join Date: May 2008 Location: Wesley Chapel, FL, USA Posts: 7,716	Re: What's your fuel Mileage? My diesel gets 22hwy, but I was doing 75-90, if I did 60-70 I'd probably get 25 easy. __________________ ~Bradley~ 2004 Black GTO LS2/T56 too much to list Miss having a truck

08-10-2009, 10:27 PM	#13
Bow Tie Scottie Registered User Join Date: Nov 2008 Location: Duluth, GA Posts: 80	Re: What's your fuel Mileage? Why would you ask? O.K., my 86 gets about an average of 8 to 10. BTW, I hope the feds aren't looking.

08-14-2009, 02:08 PM	#14
nlped Senior Member Join Date: Jul 2009 Location: Hayden, Al. Posts: 4,148	Re: What's your fuel Mileage? I average 14-16 mpg with mixed driving. I have gotten 18 mpg once on a road trip running 72 in the fall w/ no air running. '87 GMC 2wd w/ 350 TBI, 700r4, & 3.42 rear. But I had the stock 2.73 rearend when I got the 18 mpg. Cheers, Ed __________________ Carter 1968 Chevy SWB Fleet... Walt 1963-1/2 Ford Falcon Futura...Martha

08-14-2009, 09:36 PM	#15
Stitch Account Suspended Join Date: Jul 2008 Location: Where I come from, it's cornbread and chicken... Posts: 3,122	Re: What's your fuel Mileage? I get 26 city/22 highway 1/2ton swb 2wd, 6.2 diesel, 700r4, 3.42 gear... and the injection pump is turned up some...go figure

08-15-2009, 04:42 PM	#16
KQQL IT At the body shop. Join Date: Aug 2009 Location: Land of fruits and nuts. Posts: 5,257	Re: What's your fuel Mileage? Hmmm when the gauge says 1/8th its time for more gas... I thought it was more about smiles per mile __________________ " That didnt make it any newer " " Dont antique the equipment "



Register or Log In To remove these advertisements.

08-15-2009, 05:45 PM	#17
Manbearpig Registered User Join Date: Mar 2009 Location: Midland, Tx Posts: 418	Re: What's your fuel Mileage? About 5MPG in the K5 14 City/17 Highway in the 04 Sierra __________________ 1972 GMC C10

08-17-2009, 02:47 PM	#18
rome704 Registered User Join Date: Feb 2009 Location: NC Posts: 85	Re: What's your fuel Mileage? 50 feet 2 da gallon lol more like 10 mpg __________________ Roman "LCPL" Planter The Few The Proud The Marines

08-17-2009, 02:57 PM	#19
Sniper X Registered User Join Date: Aug 2009 Location: Albuquerque New mexico Posts: 169	Re: What's your fuel Mileage? When I do get the clutch in the 74, Ill bet i get about the same as the big block! The 350 never was a great gas mileage monster in a C20...even with the 4 speed.

08-18-2009, 02:04 AM	#20
texastruckjunky Registered User Join Date: May 2009 Location: San Antonio,Texas Posts: 220	Re: What's your fuel Mileage? mine has a 454 with .505 lift cam. 1 over the RV cam. Headers 2 1/2 exhaust w/flowmasters and a factory Holly spreadbore carb. In town about 6-8 driving like grandpa. Hwy 9-11 55-60.

Register or Log In To remove these advertisements.