Poor mpg

[Divinechaos]

I've got a 98 c1500 Silverado. 4.3 vortex. Long bed single cab. I haven't been able to get better than 15 on the he highway. Runs very well. It's up on service, what are things to look for that would explain the poor mpg? 

[newdude]

Speed driven, proper tire inflation, mud tires vs say an all terrain or highway tire, bad gas, bad O2 sensors, etc.  The variables are endless, or, maybe that's just what it gets.    

 

Might try searching the 88-99 section of the forum?  1988-1999 Chevrolet & GMC C/K GMT400 Platform - GM-Trucks.com

Edited June 1, 2023 by newdude

[KARNUT]

Just for grins I looked it up. It’s not that far off depending on gearing, tires etc.