1998 Silverado 5.0 Poor Gas Mileage

GMC
Avatar
SNIPE1
  • MEMBER
  • 2 POSTS
I'm trying to find out does GM offers any trucks that have great gas milage like my 2 buddies 1996 Z-71 4x4 Silverado 5.7 they get 25-28mph, I have a 1998 Z-71 4x4 Silverado 5.0 and get 18 mph :evil: . I need to know why does the bigger moter get better gas milage. Is the gearing different? I was thinking about buying 2003/4 Silverado or Avalanche with the 5.3 but I'm scared of the gas milage. Is there a difference in the "Z-71" package?

All I do is hunt and fish and cant afford the gas bill.
Thanks

D.
Feb 6, 2006 at 11:58 PM
Advertisement
Avatar
2CARPRO JACK
  • ✓Experienced Mechanic
  • 11,533 POSTS
the 5L engine was a mistake in my eyes. Poor power and economy. The new 5.3L engines are nice, small bore for economy, a little more rpm's than your friends 350's. Z-71 is mostly suspension
Feb 7, 2006 at 9:51 AM
Avatar
SNIPE1
  • MEMBER
  • 2 POSTS
So are the trannys different? How is the 5.3 gas milage?
Feb 7, 2006 at 10:42 PM
Avatar
NOS155
  • MEMBER
  • 16 POSTS
if u want good mileage for a chev pickup id go with 1996 or newer seeing they are the nice vortec engines which get good mileage. 25-28 mpg seems a bit unrealistic to me but 21 mpg is posible on the highway with these engines. i own a 1995 Z71 with the older version of the 350 and i get about 275 miles to a tank of gas which is worth getting rid of if you like your truck.
Apr 29, 2006 at 9:47 PM
🔧 Tools & Auto Repair Parts
Find automotive tools, diagnostic equipment, and replacement parts for your next repair.
Shop on Amazon →
Paid affiliate link. As an Amazon Associate, we earn from qualifying purchases.

Suggested Repair

The 5.0 is viewed as a poor power and economy engine. A later 5.3 is considered a better economy design, with a smaller bore and slightly higher rpm than the 5.7. The Z71 package is mostly suspension and does not explain the mileage difference.

Conversation Summary

The owner of a 1998 Z71 4x4 Silverado 5.0 reports about 18 mpg and asks why friends' 1996 Z71 4x4 Silverado 5.7 trucks reportedly get 25-28 mpg, whether gearing or the Z71 package differs, and what to expect from a 2003-2004 Silverado or Avalanche 5.3. The expert said the 5.0 has poor power and economy, described the 5.3 as a nicer small-bore engine that runs a little more rpm than the 5.7, and said Z71 is mostly suspension. Another reply said 1996-and-newer Vortec engines are preferable, that 25-28 mpg is unrealistic, and that about 21 mpg on the highway is possible.

Related Repair Questions

Add a reply
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.

Ask a new question

Frequently Asked Problems for This Vehicle