Notices
GM Drivetrain & Suspension Chassis | Transmission| Driveshaft | Gears/Rear End/Differential | Traction Aids

3.42s to 3.23s better highway mpg?

Thread Tools
 
Search this Thread
 
Old 02-16-2013, 11:36 PM
  #1  
TECH Apprentice
Thread Starter
 
Camin00's Avatar
 
Join Date: Oct 2012
Posts: 379
Likes: 0
Received 0 Likes on 0 Posts
Default 3.42s to 3.23s better highway mpg?

2wd 5.3L on 30" 20's 3.42s 4L60e
full bolt ons, milled .03 862, 210/218 116lsa tq cam dyno tuned 336rwtq before cam no cam dynos

truck gets around 23 highway at 70-75mph

planing on putting a posi in. Now would be the time to change gears

The truck makes a ton of tq and accelerates pretty fast under 1500 rpms

Was thinking with this much tq 3.23s shouldn't make it bog/lug and would give 1-2 mpgs better. What do yall think

It's a mild build dd doesnt hardly tow
Old 02-16-2013, 11:43 PM
  #2  
TECH Regular
 
offroadrider12's Avatar
 
Join Date: Feb 2010
Location: Michigan
Posts: 426
Likes: 0
Received 1 Like on 1 Post
Default

If I was pulling 23 mpg I would be jumping up and down with joy. With 20" rims and 30" tires I'm not sure you would get any benefit from switching down to 3.23s, might make it lug too much.
Old 02-17-2013, 09:36 AM
  #3  
TECH Regular
iTrader: (2)
 
jiar577's Avatar
 
Join Date: Nov 2008
Posts: 449
Received 0 Likes on 0 Posts
Default

Unless you live in the highway, driving over 75mph all the time on flat ground and never hit the streets in the city, stay with what you have.
Old 02-17-2013, 09:47 AM
  #4  
TECH Fanatic
iTrader: (38)
 
Join Date: Oct 2005
Location: cedar bluff,alabama
Posts: 1,299
Likes: 0
Received 2 Likes on 2 Posts
Default

What he said^^^^^ I hated the 3.23's in my crew even with the 6.0 they sucked. Turbo only gears in my book. Keep your 3.42's and be happy
Old 02-17-2013, 09:53 AM
  #5  
TECH Fanatic
iTrader: (3)
 
gamble686's Avatar
 
Join Date: Apr 2011
Location: Arizona
Posts: 1,642
Likes: 0
Received 2 Likes on 2 Posts
Default

It will lug. My truck feels like it lugs with 3.42s. If you are getting 23 you can't expect any improvement no how no way unless you swap to a 5speed.
Old 02-17-2013, 01:16 PM
  #6  
TECH Apprentice
Thread Starter
 
Camin00's Avatar
 
Join Date: Oct 2012
Posts: 379
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by 1969x11
What he said^^^^^ I hated the 3.23's in my crew even with the 6.0 they sucked. Turbo only gears in my book. Keep your 3.42's and be happy
Sold on keeping the 3.42s b/c the 6.0 makes some TQ and if that bogs with 3.23s then this lil 5.3 will to

I really want 3.73s but do mostly highway driving so these would probably drop my fuel millage down to 19-20

I wish someone would invent a dual gear system. have 4.10s for around town push a button for 3.23s on the highway < cool idea somebody steal it haha
Old 02-17-2013, 01:18 PM
  #7  
TECH Apprentice
Thread Starter
 
Camin00's Avatar
 
Join Date: Oct 2012
Posts: 379
Likes: 0
Received 0 Likes on 0 Posts
Default

Do yall think 3.55s would pull harder or hurt mpgs?
Old 02-17-2013, 01:20 PM
  #8  
TECH Apprentice
Thread Starter
 
Camin00's Avatar
 
Join Date: Oct 2012
Posts: 379
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by gamble686
It will lug. My truck feels like it lugs with 3.42s. If you are getting 23 you can't expect any improvement no how no way unless you swap to a 5speed.
Maybe if I went back to stock 16's and 28" tires??? but then it would look as clean

When I put these 20's on I had a CAI and exhaust. It dramatically slowed the truck down
Old 02-17-2013, 01:40 PM
  #9  
Baltimore Whore
iTrader: (95)
 
Mangled03gmc's Avatar
 
Join Date: Apr 2004
Location: In a van DOWN BY THE RIVER
Posts: 16,820
Likes: 0
Received 2 Likes on 2 Posts
Default

If your getting 23mpg I would not even be complaining or worrying about it.. 23's are a **** gear..
Old 02-17-2013, 05:07 PM
  #10  
TECH Fanatic
iTrader: (3)
 
gamble686's Avatar
 
Join Date: Apr 2011
Location: Arizona
Posts: 1,642
Likes: 0
Received 2 Likes on 2 Posts
Default

You are running at max efficiency as it is now. Swapping to lighter wheels would help a tiny bit your 30" tires are a great size tho.


Quick Reply: 3.42s to 3.23s better highway mpg?



All times are GMT -5. The time now is 10:28 PM.