yet another MPG thread - Page 3 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

87GMCChris · 07-15-2010, 11:09 PM

Any thoughts on an 87 lwb 305 tbi, th400 and stock gears... all i know its a ten bolt. Any idea what i would get? I know this question gets asked alot but i kinda think it would be cool to know... not that it really matters, its a toy anyhow.

thanks
Chris.

Bad70sbchevy · 07-15-2010, 11:52 PM

im gettin around 9 miles a gallon with a 355 w/ double pumer hooked up to a TH400 and 3.07 gears in my 1970 C10 daily driver.

asphaltburner · 07-16-2010, 12:10 AM

Yo!
About 12 with FRANKENTRUCK's build,...but they're all "smiles per gallon", as well!! Not much else like it.
Todd.

kikkegek · 08-09-2010, 05:21 AM

Mine gets about 7 MPG with a TH400 and a 350 engine, 4.1 gear ratio and a rochester quadrajet.

When I read the numbers in this topic, I get the feeling that mine needs a tune up.

We driver about 50/50 highway and city. On the highway doing about 55 MPH and in the city we are allowed to drive 30 MPH here in the Netherlands.

It runs on LPG (Liquefied Petroleum Gas) wich costs € 0,57 per liter here in the Netherlands compared to € 1,54 per liter for regular gas.

any ideas on how to improve my mileage?

D13 · 08-09-2010, 06:04 AM

6.2 700R4 3,08 23-26MPG diesel
99 2500 Xcab 2wd 5.3 4l60E 3.43 15mph at 5600 lbs

*C-10 simplex* · 08-09-2010, 09:46 AM

With the crate 350, i got on average 15.8 with a high of 17.20 one week.

With the "new" 305 the last tank was 16.20 and the choke wasn't adjusted right; Hopefully the next tank will be higher.

Average fillup costs are about $48.50 per tank.

1) One thing to factor in is that alot(possibly most) gas stations are carrying E10/E15; This doesn't help mileage and very probably hurts it.

Will post website listing stations that sell only 100% gas if and when i get to it.

2) Another thing that many people many not realize is that the stock air cleaner is actually going to help you get better mpg----provided all the hoses are hooked up properly and the air door is working properly; Warmer air=denser air=less fuel burned=better mpg. Takes away power though.

WigglesTheHoly · 08-09-2010, 09:49 AM

I have no idea what I'm getting but now I'm interested and will have to figure it up on my next fueling cycle

thirdstreettito · 08-09-2010, 11:56 AM

The burb in my sig. 23MPG Highway, I still have to build a cold air intake and water/mist injection. So I should be at around 25mpg when done.

BigRed76 · 08-09-2010, 01:07 PM

Quote:

Originally Posted by thirdstreettito

The burb in my sig. 23MPG Highway, I still have to build a cold air intake and water/mist injection. So I should be at around 25mpg when done.

wow. makes me want a 6.2 diesel

thirdstreettito · 08-10-2010, 12:32 AM

Quote:

Originally Posted by BigRed76

wow. makes me want a 6.2 diesel

So get one! I count the 0-60 on flat ground at about 10 seconds. Not bad for #6000. Its nice and fast and pulls anything with great mileage.

Bus Ted Knuckle · 08-10-2010, 12:49 AM

I got as much as 14 from my stock 350/350 3.08 geared 69 lwb. But I drive it like an old man.

BigRed76 · 08-10-2010, 01:56 AM

Quote:

Originally Posted by thirdstreettito

So get one! I count the 0-60 on flat ground at about 10 seconds. Not bad for #6000. Its nice and fast and pulls anything with great mileage.

I will, soon lol just need to save up a little

West Texas Z · 08-10-2010, 10:50 AM

I get about 10ish

gloriavoxdei · 08-10-2010, 09:19 PM

'85 K30 Crew Cab Dually, 454, TH400, 3.73 with 34's and I get 8 mpg driving to work and back which is 14 miles with a 1000 ft elevation gain and many hills. I haven't driven it on the highway since I bought it and got it tuned up for the elevation (it was WAY too rich and didn't have nearly enought advance for 8,600 ft where I live.

67_C-30 · 08-10-2010, 11:59 PM

'84 M1009 CUCV Blazer 6.2/TH400/3.08

I've checked mileage twice so far, and I got 20.2 the first time and 21.4 the second. This is mixed driving, but more in town than highway. I gotta think 22 - 23 is totally possible on the highway. I have a Banks Sidewinder turbo kit that I'm going to install soon. I've heard some people say the Banks kit slightly decreased their mileage and I've heard others say it got slightly better. For the proven 100+ lb ft gain in torque, I'd be OK with a little loss.

grayharville · 08-11-2010, 12:44 AM

My 84 GMC lwb (350, 700r4,3.08, 255/75/r15) got 14 last tankfull, with me driving it somewhat aggressively. if im on the highway i go 70-80 mph, i was expecting less, so im happy.

My 70 chevy lwb (350 with 600 double pumper,th350,3.73) gets roughly 8-10, with me driving it like i stole it, I have ALOT of fun, so im happy.

On the other hand, my 2000 chevy swb (4.3,4l60,3.73 4x4) gets 10. best ive ever gotten was 12. for a fuel injected truck? FAIL. screw V6s. ill take my SBC over the v6 anyday!

Bad70sbchevy · 08-11-2010, 09:24 AM

Quote:

Originally Posted by kikkegek

Mine gets about 7 MPG with a TH400 and a 350 engine, 4.1 gear ratio and a rochester quadrajet.

When I read the numbers in this topic, I get the feeling that mine needs a tune up.

We driver about 50/50 highway and city. On the highway doing about 55 MPH and in the city we are allowed to drive 30 MPH here in the Netherlands.

It runs on LPG (Liquefied Petroleum Gas) wich costs € 0,57 per liter here in the Netherlands compared to € 1,54 per liter for regular gas.

any ideas on how to improve my mileage?

Just throwing it out there, recken your carb is not calibrated to run LPG?

kikkegek · 08-11-2010, 10:22 AM

Quote:

Originally Posted by Bad70sbchevy

Just throwing it out there, recken your carb is not calibrated to run LPG?

Thanks for your reply.

I would not know. My car also runs on regular fuel, just for backup, but it should be set for LPG now, because that is the main fuel. I will give the company that fitted the system a call and ask them what they did exactly.

dmartin1 · 08-12-2010, 03:06 AM

im assuming mine is about -12 lmao

325hp 355 sbc turbo 350 stock gearing 3/4 4x4 with air conditioning lifted 4" on 35" mudders.its horrible..

and its a daily driver.

flamingbig10 · 08-12-2010, 03:49 AM

Quote:

Originally Posted by dmartin1

im assuming mine is about -12 lmao

325hp 355 sbc turbo 350 stock gearing 3/4 4x4 with air conditioning lifted 4" on 35" mudders.its horrible..

and its a daily driver.

that actually normal mine gets half that and mines daily-ed. but thats why I'm going with a 6.0 and 4l80 I'm hopping for 12 to 14 in town

chevy283 · 09-17-2010, 06:55 PM

My 4barrel 305 with th350 3.73 gears, I think gets feet per gallon.

76/85 Truck · 09-17-2010, 09:29 PM

I get about 8-12 depending on what I'm doing. 350 bored 40 over with 4 barrel Edelbrock and dual exhaust with cherry bombs, full time four wheel drive and TH-350. The Full time 4x4 kills it. The worse I've ever got was 5 or so.. Getting firewood.

piecesparts · 09-17-2010, 10:08 PM

385 stroker engine, with 700 R4 and 3:73 gears and 28" tall tires====15 MPG Highway---a lot less on the city street cruisin (Wink wink)

1985-GMC · 09-17-2010, 10:35 PM

My old C30 with 4:10 gears got 7-8 with my foot in it all the time. I once got 12 out of it for no reason, redid my math over and over and never could figure out why it went up.

View Poll Results: Dis-Placed-Ment------what do you drive?
\| 6	3	4.00%
350	50	66.67%
383	2	2.67%
454	10	13.33%
other (please list)	11	14.67%
Multiple Choice Poll. Voters: 75. You may not vote on this poll

07-15-2010, 11:09 PM	#51
87GMCChris Registered User Join Date: May 2010 Location: London, Ontairio Posts: 163	Re: yet another MPG thread Any thoughts on an 87 lwb 305 tbi, th400 and stock gears... all i know its a ten bolt. Any idea what i would get? I know this question gets asked alot but i kinda think it would be cool to know... not that it really matters, its a toy anyhow. thanks Chris. __________________ 1987 GMC Wrangler - 305TBI/TH400/Duals 1968 Camaro - Resto 2010 Ranger I only drive truck 6 months a year... Dam Canadian winters.

07-15-2010, 11:52 PM	#52
Bad70sbchevy Registered User Join Date: Aug 2009 Location: Newberry,FL Posts: 277	Re: yet another MPG thread im gettin around 9 miles a gallon with a 355 w/ double pumer hooked up to a TH400 and 3.07 gears in my 1970 C10 daily driver.

07-16-2010, 12:10 AM	#53
asphaltburner Registered User Join Date: Jul 2008 Location: Ault, Colorado Posts: 862	Re: yet another MPG thread Yo! About 12 with FRANKENTRUCK's build,...but they're all "smiles per gallon", as well!! Not much else like it. Todd. __________________ '78 3/4 ton 4x4 custom "Todd-built" FRANKENTRUCK!

08-09-2010, 05:21 AM	#54
kikkegek Registered User Join Date: Aug 2010 Location: Netherlands, The Hague Posts: 1,520	Re: yet another MPG thread Mine gets about 7 MPG with a TH400 and a 350 engine, 4.1 gear ratio and a rochester quadrajet. When I read the numbers in this topic, I get the feeling that mine needs a tune up. We driver about 50/50 highway and city. On the highway doing about 55 MPH and in the city we are allowed to drive 30 MPH here in the Netherlands. It runs on LPG (Liquefied Petroleum Gas) wich costs € 0,57 per liter here in the Netherlands compared to € 1,54 per liter for regular gas. any ideas on how to improve my mileage? __________________ My dreamride / project:1977 GMC C15 Suburban In storage: Monster - 1974 GMC Suburban 25hundred Sold : Chevrolet Suburban K20 Silverado 1986 Guide: real HID projectors for 4x6 headlights link: DIY LED TAILLIGHTS Last edited by kikkegek; 08-09-2010 at 05:34 AM.

08-09-2010, 06:04 AM	#55
D13 Registered User Join Date: Feb 2007 Location: Memphis MI Posts: 1,851	Re: yet another MPG thread 6.2 700R4 3,08 23-26MPG diesel 99 2500 Xcab 2wd 5.3 4l60E 3.43 15mph at 5600 lbs __________________ 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 Last edited by D13; 08-09-2010 at 06:04 AM.

08-09-2010, 09:46 AM	#56
C-10 simplex Account Suspended Join Date: Dec 2008 Location: indisclosed Posts: 1,515	Re: yet another MPG thread With the crate 350, i got on average 15.8 with a high of 17.20 one week. With the "new" 305 the last tank was 16.20 and the choke wasn't adjusted right; Hopefully the next tank will be higher. Average fillup costs are about $48.50 per tank. 1) One thing to factor in is that alot(possibly most) gas stations are carrying E10/E15; This doesn't help mileage and very probably hurts it. Will post website listing stations that sell only 100% gas if and when i get to it. 2) Another thing that many people many not realize is that *the stock air cleaner is actually going to help you get better mpg-*---provided all the hoses are hooked up properly and the air door is working properly; Warmer air=denser air=less fuel burned=better mpg. Takes away power though.

08-09-2010, 09:49 AM	#57
WigglesTheHoly IT Guy/ Father/ Chevy lover Join Date: Feb 2010 Location: Hoisington, KS Posts: 568	Re: yet another MPG thread I have no idea what I'm getting but now I'm interested and will have to figure it up on my next fueling cycle __________________ 78 Chevy (Pictures) SOLD 79 Chevy LWB (pasture) 83 Chevy LWB (crushed rusted beyond repair) 02 TrailBlazer SOLD 03 VW Passat wagonSOLD 95 extended cab silveradoSOLD (still in family) 05 Crew Cab Silverado 5.3 (The Turd) WTB: 66 El camino Technology Specialist aspiring to be a gear head.

08-09-2010, 11:56 AM	#58
thirdstreettito Resident of Here Join Date: May 2008 Location: Wesley Chapel, FL, USA Posts: 7,716	Re: yet another MPG thread The burb in my sig. 23MPG Highway, I still have to build a cold air intake and water/mist injection. So I should be at around 25mpg when done. __________________ ~Bradley~ 2004 Black GTO LS2/T56 too much to list Miss having a truck

08-10-2010, 12:49 AM	#61
Bus Ted Knuckle Son of a gun Join Date: Jan 2007 Location: Hot Springs, Arkansas Posts: 1,636	Re: yet another MPG thread I got as much as 14 from my stock 350/350 3.08 geared 69 lwb. But I drive it like an old man. __________________ Bill BEATERS ARE NEATER

08-10-2010, 10:50 AM	#63
West Texas Z El Mero Mero Frijolero!! Join Date: Mar 2010 Location: Lubbock, Texas Posts: 669	Re: yet another MPG thread I get about 10ish __________________ My Toys: 1993 Ford Mustang LX 5.0 2001 Yamaha V Star 650 1984 Silverado > Build Page <

08-10-2010, 09:19 PM	#64
gloriavoxdei Registered User Join Date: May 2010 Location: Florissant, CO Posts: 97	Re: yet another MPG thread '85 K30 Crew Cab Dually, 454, TH400, 3.73 with 34's and I get 8 mpg driving to work and back which is 14 miles with a 1000 ft elevation gain and many hills. I haven't driven it on the highway since I bought it and got it tuned up for the elevation (it was WAY too rich and didn't have nearly enought advance for 8,600 ft where I live. __________________ 1978 GMC Jimmy, 400, th350, np203 with part time conversion, Fibrecraft popup camper, soon to get a 14 bolt/d44 swap 2001 Yukon XL2500, 6.0, 4L85E, 4x4, family truckster

08-10-2010, 11:59 PM	#65
67_C-30 I have a radical idea! Join Date: Jan 2005 Location: Sweet Home Alabama! Posts: 6,513	Re: yet another MPG thread '84 M1009 CUCV Blazer 6.2/TH400/3.08 I've checked mileage twice so far, and I got 20.2 the first time and 21.4 the second. This is mixed driving, but more in town than highway. I gotta think 22 - 23 is totally possible on the highway. I have a Banks Sidewinder turbo kit that I'm going to install soon. I've heard some people say the Banks kit slightly decreased their mileage and I've heard others say it got slightly better. For the proven 100+ lb ft gain in torque, I'd be OK with a little loss. __________________ '67 C-30 Dually Pickup 6.2 Turbo Diesel, NP435 ‘72 C-10 SWB , 350 4bbl, TH350 '69 C-10 SWB , 250 L6, 3 OTT '69 GMC C3500, dump truck, 351 V6, NP435 '84 M1009 CUCV Military Blazer 67 C-30 Turbodiesel build thread http://67-72chevytrucks.com/vboard/s...d.php?t=254096 My trucks http://s226.photobucket.com/albums/d...ediafilter=all Member of the 1-Ton Club!

08-11-2010, 12:44 AM	#66
grayharville ^^who I am^^ what I say> Join Date: Jun 2009 Location: Murchison, Tx Posts: 992	Re: yet another MPG thread My 84 GMC lwb (350, 700r4,3.08, 255/75/r15) got 14 last tankfull, with me driving it somewhat aggressively. if im on the highway i go 70-80 mph, i was expecting less, so im happy. My 70 chevy lwb (350 with 600 double pumper,th350,3.73) gets roughly 8-10, with me driving it like i stole it, I have ALOT of fun, so im happy. On the other hand, my 2000 chevy swb (4.3,4l60,3.73 4x4) gets 10. best ive ever gotten was 12. for a fuel injected truck? FAIL. screw V6s. ill take my SBC over the v6 anyday! __________________ 70 chevy LWB 350/TH350 Barn find (AKA the 70) http://www.67-72chevytrucks.com/vboa...d.php?t=406364 East Tx Squares

08-12-2010, 03:06 AM	#69
dmartin1 Registered User Join Date: Aug 2008 Location: mohave valley,arizona Posts: 1,088	Re: yet another MPG thread im assuming mine is about -12 lmao 325hp 355 sbc turbo 350 stock gearing 3/4 4x4 with air conditioning lifted 4" on 35" mudders.its horrible.. and its a daily driver. __________________ 1969 Shortbed in progress 1982 short step, few suspension and motor upgrades.getting a 468 1978 Shortbed fleet side bonanza fully loaded 1978 k20 Silverado loaded.currently engine-less 1989 k10 suburban 9" lift 65 nova And more



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09-17-2010, 06:55 PM	#71
chevy283 Registered User Join Date: Dec 2004 Location: wilson oklahoma Posts: 367	Re: yet another MPG thread My 4barrel 305 with th350 3.73 gears, I think gets feet per gallon. __________________ 65 c10 tore apart 70 c10 305/350th

09-17-2010, 09:29 PM	#72
76/85 Truck Registered User Join Date: Jun 2010 Location: Libby, MT Posts: 163	Re: yet another MPG thread I get about 8-12 depending on what I'm doing. 350 bored 40 over with 4 barrel Edelbrock and dual exhaust with cherry bombs, full time four wheel drive and TH-350. The Full time 4x4 kills it. The worse I've ever got was 5 or so.. Getting firewood. __________________ Rich My first truck!! 1976 Chevy 3/4 ton Camper Special and a 1985 GMC body. Has a 350, 4 BBL Edelbrock, with a Turbo 350, and NP205 T-case.

09-17-2010, 10:08 PM	#73
piecesparts Parts and more parts Join Date: Nov 2003 Location: Lebo, Kansas (middle of nowhere Posts: 6,821	Re: yet another MPG thread 385 stroker engine, with 700 R4 and 3:73 gears and 28" tall tires====15 MPG Highway---a lot less on the city street cruisin (Wink wink) __________________ Frank

09-17-2010, 10:35 PM	#74
1985-GMC Chevy Enthusiast Join Date: Jul 2009 Location: Canyon Lake Texas Posts: 2,024	Re: yet another MPG thread My old C30 with 4:10 gears got 7-8 with my foot in it all the time. I once got 12 out of it for no reason, redid my math over and over and never could figure out why it went up. __________________ Tony 1985 GMC K2500 restoration Project: Rust, White & Blue 1989 Chevy R3500 CC Cummins & 4X4 swap some day... 1989 Burb (D60, 14BFF, 12V, NV4500, NP205, 37" tires in progress)

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