I usually average 15 mpg with 50/50 highway and traffic miles. I usually shoot for 350+ per tank and fill with 24 gallons.

Last week, I filled up with non-city gas (non-oxygenated). I went over 400 miles that tank, but I did push the gauge hard to "E".

I dont think thats too bad for a 4x4 weighing well over 5000 lbs and a heavy foot.

-99 Excab Silverado 5.3 Z71

 

I got 420 on the last tank and filled up with 22 gallons. That's about 19mpg @ 80mph on the highway. I've gotten over 20 before but, that was very calm highway driving. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Nobody can ever believe how good the gas mileage is on these trucks. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

John

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by XLR8NSS:
<strong>I got 420 on the last tank and filled up with 22 gallons. That's about 19mpg @ 80mph on the highway. I've gotten over 20 before but, that was very calm highway driving. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Nobody can ever believe how good the gas mileage is on these trucks. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

John</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">what size gear and tires do you have?

 

Under hard driving conditions w/the s/c i get about 3-4mpg. When i act like a law biding citizen i get about 12 mpg

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by graygmc:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by XLR8NSS:
<strong>I got 420 on the last tank and filled up with 22 gallons. That's about 19mpg @ 80mph on the highway. I've gotten over 20 before but, that was very calm highway driving. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Nobody can ever believe how good the gas mileage is on these trucks. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

John</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">what size gear and tires do you have?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I've got 3.42 gears and 31" tall tires. I'll have to look to see what width the tires are. This makes a great highway combo. You can still hit passing gear doing just over 70mph. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

John

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Maxmumboom:
<strong>Under hard driving conditions w/the s/c i get about 3-4mpg. When i act like a law biding citizen i get about 12 mpg</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">ok so whatever ideas i had of a supercharger are now gone <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />