The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Engine & Drivetrain

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 03-22-2011, 09:54 AM   #26
Clyde65
1965 Chevy C10, 2005 4.8L/4l60
 
Clyde65's Avatar
 
Join Date: Aug 2004
Location: DFW Texas
Posts: 8,546
Re: Better gas mileage

Quote:
Originally Posted by roofingbloke View Post
Hi guys, good topic,

Just thought i would mention that petrol in the UK is £1.40 per litre,

But you cannot put a price on the smile you get on your face when you drive a classic car/truck.

Wow! thats over $9.00 a gallon US!

Would we drive our trucks if fill ups cost $180.00? YOUR DARN RIGHT WE WOULD!
__________________
Clyde65

Rebuild of Clyde
http://67-72chevytrucks.com/vboard/s...84#post8338184

69 Aristocrat Lo Liner build
http://67-72chevytrucks.com/vboard/s...84#post7561684



support our troops!
Clyde65 is offline   Reply With Quote
Old 03-22-2011, 11:33 AM   #27
stich626
Account Suspended
 
Join Date: Sep 2010
Location: hingham ma
Posts: 1,721
Re: Better gas mileage

find a 3.08 rear gear and install it, or change out the whole rear if easier than setting up gears..
those 4.56 are killing you..
stich626 is offline   Reply With Quote
Old 03-22-2011, 04:41 PM   #28
Longhorn Man
its all about the +6 inches
 
Longhorn Man's Avatar
 
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,690
Re: Better gas mileage

getting a 3.08 gear would be a pain and then you start getting into fab work since it would most likely be a 14 bolt later model rear.
Longhorn Man is offline   Reply With Quote
Old 03-22-2011, 05:22 PM   #29
Clyde65
1965 Chevy C10, 2005 4.8L/4l60
 
Clyde65's Avatar
 
Join Date: Aug 2004
Location: DFW Texas
Posts: 8,546
Re: Better gas mileage

I have a 3.07/8 in my 12 bolt 72 rear.
__________________
Clyde65

Rebuild of Clyde
http://67-72chevytrucks.com/vboard/s...84#post8338184

69 Aristocrat Lo Liner build
http://67-72chevytrucks.com/vboard/s...84#post7561684



support our troops!
Clyde65 is offline   Reply With Quote
Old 03-22-2011, 05:48 PM   #30
NONHOG
Registered User
 
NONHOG's Avatar
 
Join Date: Feb 2007
Location: Marana, Arizona
Posts: 3,455
Re: Better gas mileage

Couple of thoughts here.
Breathing is a factor maybeif you keep the high # gears.
The easy way to get better mpg is to lower speed. Engine and vehicle.
If your engine speed (rpm) is down better breathing wont mean much as it breaths plenty at low rpm's.

Aero gains should be considered, like LHM said about holding your hand out the window at speed. Try holding a truck mirror vs. a sport mirror.
Bed cover, Grill block, narrow tires?, vac gauge.

Take a look here.... http://ecomodder.com/forum/fuel-econ...ifications.php

There are a few truck guys on that site. Some of there ideas work but I wouldn't do them. Engine kill switch, teeny tiny car.
Some good ideas.
__________________
"I feel the need for speed!"... as soon as I am done with my nap.
NONHOG is offline   Reply With Quote
Old 03-22-2011, 06:53 PM   #31
'68OrangeSunshine
Senior Member
 
'68OrangeSunshine's Avatar
 
Join Date: Feb 2002
Location: Tucson, AZ USA
Posts: 7,504
Re: Better gas mileage

Quote:
Originally Posted by Longhorn Man View Post
Since I do not know much about inlines, I would recomend looking into it more before laying down the cash for expensive inline parts. The header could help with low end torque and actually help, or it may just be money spent that you won't see improvements on.
If you are looking to make power, then go for it, but for higher MPG, do some more research. I think there's an inliners forum that would be ideal for your questions.
Hey Andy, That's: www.inliners.org
__________________


Every 25 years I like to rebuild that 292, whether it needs it or not.
'68OrangeSunshine is offline   Reply With Quote
Old 03-22-2011, 10:37 PM   #32
Longhorn Man
its all about the +6 inches
 
Longhorn Man's Avatar
 
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,690
Re: Better gas mileage

Quote:
Originally Posted by Clyde65 View Post
I have a 3.07/8 in my 12 bolt 72 rear.
You have a half ton, he has a 3/4 ton. Since there's been no talk of making his a 1/2 ton truck, I can only assume he has no interest in a 12 bolt rear. If he is willing to do a suspention swap, then yes, a 3.07 (3.08 was a car gear) 12 bolt would be the way to go.

Quote:
Originally Posted by '68OrangeSunshine View Post
Hey Andy, That's: www.inliners.org
inliners.org... that's the one I was thinking of... thanks for the link!
Longhorn Man is offline   Reply With Quote
Old 03-23-2011, 07:24 AM   #33
D13
Registered User
 
D13's Avatar
 
Join Date: Feb 2007
Location: Memphis MI
Posts: 1,851
Re: Better gas mileage

3.42's in 14bolt SF, 8 bolt 16/16.5, any light 3/4 ton. That's how the 81 above was set up, and I could make it get 15's pretty easily. Taller tires would help, I was running about 31's.

3.23's were an option but rare.

Clifford will hurt your mpg (it's more of an RPM manifold) but the headers should help slightly.

It's those rear gears that are the killer. Which axle do you have, 12 bolt or Eaton?
__________________
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; 03-23-2011 at 07:28 AM.
D13 is offline   Reply With Quote
Old 04-15-2011, 07:51 PM   #34
Junkpyl
Registered User
 
Join Date: Jan 2007
Location: Scottsdale Arizona
Posts: 125
Re: Better gas mileage

I'm running half ton gear and I believe 3.42's with a 2004r overdrive automatic.
Junkpyl is offline   Reply With Quote
Old 05-02-2011, 08:57 AM   #35
treeboy97
Registered User
 
treeboy97's Avatar
 
Join Date: May 2009
Location: Waynesville, Ohio
Posts: 136
Re: Better gas mileage

Did a test this weekend, 130 miles and ended up with 17.5 MPG.

Installed the Astro Van T5 over the winter and this was its first long drive. Very happy. I have the pertronix upgrade next to install. Plus have a new intake, split longtube headers and a Holley four barrell on the shelf in waiting

Currently I have a stock intake, carb, exhaust and 3.73 gears.
__________________
1970 C10 LWB (Grandfather's Truck) 5.3 4L60E

2012 Victory Cross Country Touring

I'm not wasting money on my truck/bike, I'm helping to rescue the economy one mod at a time.
treeboy97 is offline   Reply With Quote
Old 05-02-2011, 07:52 PM   #36
Junkpyl
Registered User
 
Join Date: Jan 2007
Location: Scottsdale Arizona
Posts: 125
Re: Better gas mileage

That sounds respectable. I have kinda the same setup as you except with an auto trans. Just purchase a new HEI and wires for it. Keep us updated as you upgrade to your aftermarket goodies on whether the mileage goes up or down. I'm still plugging along trying to put mine together. All this rain needs to stop before I can proceed any further.
Junkpyl is offline   Reply With Quote
Old 05-16-2011, 10:39 AM   #37
soxplayer
Registered User
 
Join Date: Jun 2009
Location: Forest City IA
Posts: 56
Re: Better gas mileage

My 2 cents (possible 3 cents at todays gas prices). Keep your speed down. I can get 14 MPG on the highway with a 250, 4 speed and 5.13:1 gears in a 67 C20 with the old model B carb. I have to run 60 with the engine turning over at 3500. The truck is running on the rich side with factory jetting and it has an old LMC glasspack single exhaust. Otherwise it is stock including the ignition system. Tall gear will help but you are fighting bad aerodynamics and a small engine for the load. If you gear too tall you will spend a lot of time with the powervalve open in the carb (yes even a model B has a power circuit) and your gas mileage will go away unless you are driving on flat ground with a tailwind.
soxplayer is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 06:00 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com