Chevy and GMC Duramax Diesel Forum banner

1 - 20 of 22 Posts

·
Registered
Joined
·
760 Posts
Discussion Starter #1
My wife has the 05 cc. Bought it brand new and in the five years we have owned it, I can't get any better than 14mpg with Granatelli tuner and KN filter with butchered airbox. Anyone doing something different with better results??
 

·
Registered
Joined
·
30 Posts
I had a 04 CC w/ the 6.0 that had a hypertech & KN Cold air kit and I never got 14mpg! I averaged around 12mpg on the highway and 9mpg in town. Good luck on your quest for better mileage I finally just gave up and lived w/ it.
 

·
Registered
Joined
·
206 Posts
Sounds about right, dad had a 02 2500 with the 6.0, was not the HD. Had a 3.73 rear end. Got about 15 to 16 mpg without the trailer and 9mpg with the trailer. If it is the HD, I believe they came with the 4.10 gears. So the mpg would be lower.
 

·
Registered
Joined
·
687 Posts
My wife has the 05 cc. Bought it brand new and in the five years we have owned it, I can't get any better than 14mpg with Granatelli tuner and KN filter with butchered airbox. Anyone doing something different with better results??
My '97 Tahoe has 342 gears. I run 78 mph at 2000 rpm. Bone stock and I get around 17.5 on the highway. I can get more by dropping the speed. I got almost 21 one time travelling the Natchez Trace. Of course, that's a federal parkway, heavily policed, and 50mph speed limit. I think I had the cruise set at 51 or 52.

'05 Duramax, bone stock except for the 4" exhaust, just got 18 from Knoxville to Atlanta with the cruise set at 75.

Make sure the tires are properly inflated, clean the air filter, and use the cruise whenever possible for the best mileage.
 

·
Registered
Joined
·
760 Posts
Discussion Starter #5
Just what I thought, those damn 4.10's
 

·
Registered
Joined
·
225 Posts
supercharge it.... you'll gain about 1-1.5 mpg :D





(although thats not very cost effective)
 

·
DIESEL MANIAC!!!
Joined
·
1,222 Posts
we had a 2000 ext cab/lb that never saw over 11.5 no matter what. it had the 4.10s also
 

·
Registered
Joined
·
838 Posts
Get on the phone with Nelsons Performance in San Antonio. He is well known for his GM gasser custom tuning. I think its: ls1truck.com He can get @ 23 out of a 5.3 1/2ton.
 

·
Registered
Joined
·
760 Posts
Discussion Starter #10

·
Registered
Joined
·
687 Posts
Just what I thought, those damn 4.10's
And, in case you missed it in my signature, my Tahoe is still running with the ORIGINAL engine that has over 300,000 on it!
 

·
Registered
Joined
·
760 Posts
Discussion Starter #12
Get on the phone with Nelsons Performance in San Antonio. He is well known for his GM gasser custom tuning. I think its: ls1truck.com He can get @ 23 out of a 5.3 1/2ton.
Any idea on where the prices start?
 

·
Registered
Joined
·
457 Posts
when i was doin my on my last truck i think it was about $300. he will also want to ride around for a while and dial it in perfectly. Their shop is on the south side of SA
 

·
Registered
Joined
·
760 Posts
Discussion Starter #14
And, in case you missed it in my signature, my Tahoe is still running with the ORIGINAL engine that has over 300,000 on it!
I did miss it. Now that is impressive. I put 225k on 96 GMC 1500 2wd 5.7. An awesome truck. Sold it with original motor, tranny, rearend, starter. However tranny was starting to show signs.
 

·
Registered
Joined
·
760 Posts
Discussion Starter #15
when i was doin my on my last truck i think it was about $300. he will also want to ride around for a while and dial it in perfectly. Their shop is on the south side of SA
That isn't as bad as I was thinking. What kind of improvements did you see on your last truck? What was it? This guy will definitely be eharing from me.
 

·
Registered
Joined
·
838 Posts
@ 300 last i heard. Have buddies that deal there all the time. He is the guy to see. Has all kinds of tuning. He builds the gasser trucks (daily drivers) that run 9s-10s at track in San Antonio. Really knows his stuff.
 

·
Registered
Joined
·
457 Posts
That isn't as bad as I was thinking. What kind of improvements did you see on your last truck? What was it? This guy will definitely be eharing from me.
i got bout 3mpg's when i kept my foot out of it. lots of burnt rubber also:rolleyes:.

it was a 07 NBS 2500 w/ 6.0.
 

·
Registered
Joined
·
760 Posts
Discussion Starter #18
3mpg is a great number. Thanks guys appreciate the help.
 

·
Registered
Joined
·
687 Posts
I did miss it. Now that is impressive. I put 225k on 96 GMC 1500 2wd 5.7. An awesome truck. Sold it with original motor, tranny, rearend, starter. However tranny was starting to show signs.
Yeah, tranny issues as well. As you can see, I now have a new Jasper transmission in it. The owners manual states that you will NOT hurt the transmission by towing in O/D, but that's BS. Original went out a little over 100k, and the 2nd went out at 285k. That's why I now have the DM. To tow my horse trailers, flatbed trailer with hay (or whatever), boat, etc. I figured I'd let the Tahoe enjoy the next 200k without towing.
 
1 - 20 of 22 Posts
Top