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 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 08-20-2008, 01:48 AM   #1
gchemist
BAD BOW-Silverado XST
 
gchemist's Avatar
 
Join Date: May 2000
Location: Senior Member from Austin, TX
Posts: 6,431
ZZ4 MPG Challenge II report

I finally went through my final full tank from vacation. I filled up the last tank fully used on my trip. I was surprised at the milage. I drove a little over 2 hours at 65. Only because it was night. As soon as daylight came up, I speed up to 70 MPH. I think the ZZ4 could average 22 if I kept it under 65 MPH. I was short 63 miles to reach my house from Lubbock TX. Drive was almost 4.5 hours.

Odometer Miles Fuel MPG
76131 Starting point
76430 299 15.674 19.08 one full tank at 70 MPH
76686 256 14.962 17.11 showing off
76865 179 15.561 11.50 really showing off
77197 332 15.193 21.85 65/70 MPH mix
Total miles = 1066

I'll need new rear tires by the end of summer for showing off. :biggrin:
__________________
Gerardo a.k.a. Mad Chemist
Silverado XST videos
gchemist is offline   Reply With Quote
Old 08-20-2008, 09:27 AM   #2
jblucolar63
Registered User
 
Join Date: Aug 2008
Location: surprise,arizona
Posts: 24
Re: ZZ4 MPG Challenge II report

What are you running for a stall. I finally got my engine going Saturday and took it out for a spin yesterday, but what a dog. Come to find out the converter that I was told was a 2500 is actually only a stock replacement. As for the engine it was a L98 but I had the heads done and put the ZZ4 cam and 1.6 rollers in it, topped with a 750hp Holley.
jblucolar63 is offline   Reply With Quote
Old 08-20-2008, 04:02 PM   #3
gchemist
BAD BOW-Silverado XST
 
gchemist's Avatar
 
Join Date: May 2000
Location: Senior Member from Austin, TX
Posts: 6,431
Re: ZZ4 MPG Challenge II report

Nice combo. I have a 2500 stall in it. The stall is a little high for city driving. My tach is not working. I need to fix it. It locks in at 45 MPH. It does lock a little low with normal driving. The stall feels high when I put my foot in it. The tires come really loose at the higher end stall.
__________________
Gerardo a.k.a. Mad Chemist
Silverado XST videos
gchemist is offline   Reply With Quote
Old 08-22-2008, 08:10 AM   #4
James McClure
One shot, one kill.
 
Join Date: Dec 2007
Location: Saratoga Springs NY
Posts: 859
Re: ZZ4 MPG Challenge II report

I just got back from a little vacation in Myrtle beach SC. I live in upstate NY. I had planned to get a good run in so I could get an accurate mileage reading. Well, that didn't turn out so well. First was MAJOR traffic on I81 south in PA and again on I83 south in PA!! Then the danmed odometer quit working!! Best as I can figure is about 15 MPG. I took 3 speedometers I had laying arouind and made 1 that works properly. I HATE fooling around with odometers, they are a real pain to get the numbers reset. Next long run I make I'll have better numbers to go by. I know I have hit 17 before which isn't to bad for an 84 carbed 350.jim
__________________
1984 K20 350M engine with 465,000 miles. Well, it's finally done!! Almost 2 years of work, but it was really worth the effort. Little stuff left to do is mount winch, wet sand & buff out and build belly pan\running boards. Body work takes lots and LOTS of beer!!!! God, Guts and Guns made America and God, Guts and Guns will preserve it! The worst thing you could do is get into my sights, but that don't matter, you'll never know it, cause you'll never hear the shotJim or Paladin whichever you choose.
James McClure is offline   Reply With Quote
Old 08-22-2008, 08:28 AM   #5
larrystone
Registered User
 
larrystone's Avatar
 
Join Date: Jan 2008
Location: White Haven PA
Posts: 59
Re: ZZ4 MPG Challenge II report

I bought my 1992 truck brand new and it came with the 3.08 4 speed auto combo and I was getting 25 miles to the gallon with a 500 pound motorcycle in the bed with the stock tailgate plus all the assorted drag racing gear, tools etc.

But there is a problem with that set up in a area where you go from 500 feet above sea level to 2000 feet in just a few road miles. Once I swapped in the 4.10 posi the highway miles went to 17-18mpg plus that truck has a folding mesh ramp gate the catches some air plus lawn equipment trimmer racks.

I have found that the ratio of 2.73 in my 1986 truck is best for my area with a truck that does not haul any real weight and is used for personal usage.
__________________
1992 C1500 WT LWB 4.3TBI 700r4 4.10 limited slip= Work Truck
1986 C10 Custom Deluxe LWB 4.3-4V TH350C 2.73 ac cruise tilt= Cowboy Cadillac
larrystone 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 04:10 PM.


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