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 > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 05-31-2013, 10:27 AM   #1
bsmith5455
Registered User
 
Join Date: Apr 2013
Location: pleasant hill missouri
Posts: 8
Fuel mileage

Hey all, getting ready to swap my 3/4 setup to 1/2 ton. Have a free 1982 donor truck with 2:73 rear end. I drive my truck 90 miles a day, it has a 350 with 400 turbo. Anyone else running that high of a gear, and if so, what kind of mileage you getting?
bsmith5455 is offline   Reply With Quote
Old 05-31-2013, 10:38 AM   #2
Longhorn 70
Registered User
 
Longhorn 70's Avatar
 
Join Date: Dec 2012
Location: Chandler AZ
Posts: 1,149
Re: Fuel mileage

You should also indicate tire size. With a 28" tall tire you'll be around 2129 RPM at 65mph. That sounds right in the power band. You may lose a little out of the hole as the gear will be higher which may drop mileage for stop and go.


You can check gear calculations here.
__________________
1970 Longhorn, Front Disc, 350/4 bolt, 882 heads, HEI, Edelbrock, 700R4, HO-52/4.11.
1996 Corvette, Collector Roadster, LT4, 396, 450RWHP, 6sp, 4.11/Dana44/posi 5 point roll bar

And let us not grow weary of doing good, for in due season we will reap, if we do not give up. Gal 6:9

Last edited by Longhorn 70; 05-31-2013 at 10:48 AM. Reason: math error
Longhorn 70 is offline   Reply With Quote
Old 05-31-2013, 10:46 AM   #3
cdowns
Senior Member
 
cdowns's Avatar
 
Join Date: Jan 2003
Location: daytonabeach
Posts: 22,956
Re: Fuel mileage

doubt you will see any better milage more than likely worse in the 8-9 mpg range and it sure wont b any fun around town from a stoplight
__________________
71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane

MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF

DONT BELIEVE EVERYTHING YOU THINK

TAKE MY ADVISE;I DON'T USE IT ANYWAY
cdowns is offline   Reply With Quote
Old 05-31-2013, 10:51 AM   #4
bsmith5455
Registered User
 
Join Date: Apr 2013
Location: pleasant hill missouri
Posts: 8
Re: Fuel mileage

Tire size will be 29"
bsmith5455 is offline   Reply With Quote
Old 05-31-2013, 10:58 AM   #5
Longhorn 70
Registered User
 
Longhorn 70's Avatar
 
Join Date: Dec 2012
Location: Chandler AZ
Posts: 1,149
Re: Fuel mileage

You'll be OK if you do JUST freeway driving. The starts and stops will just kill mileage.

At 65 you'll be around 2055 RPM....GOOD for mileage. Getting there will be not so good. Driving style and load will make big differences.
__________________
1970 Longhorn, Front Disc, 350/4 bolt, 882 heads, HEI, Edelbrock, 700R4, HO-52/4.11.
1996 Corvette, Collector Roadster, LT4, 396, 450RWHP, 6sp, 4.11/Dana44/posi 5 point roll bar

And let us not grow weary of doing good, for in due season we will reap, if we do not give up. Gal 6:9
Longhorn 70 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 04:36 PM.


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