Chevy Silverado and GMC Sierra Forum banner
1 - 8 of 8 Posts

·
Registered
Joined
·
210 Posts
Discussion Starter · #1 ·
I drive quite a bit, and right now with the following I get the following:

2007 CCSB 8" lift on 35's with 4.8 Tune and Servos i nthe tranny. 12.7 average in the city, and 14.4 on the highway, most of my driving is city. I'm on 3.42's now.

I want ot go 4.56's - can some people chime in with before and after mpg figures for me.

If I can improve the mpg's to say 15 and 18 then I will regear and refinance the truck = me keeping it for another 5 years or so, if I can't see 15 -18 with the regear, I'm looking at a Focus ST....

Let me know please.
 

·
Registered
Joined
·
210 Posts
Discussion Starter · #2 ·
FYI, when i got the truck Pre-tune and servos I was getting 10.3 so I know it's improvable:)
 

·
Registered
Joined
·
706 Posts
even a stock silverado with the 4.8 rarely see's 18 mpg unless you drive like my grandma. I would guess that you will not improve your MPG enough to recoup the cost of the regear. Normally regearing is done to put less of a strain on the transmission and to increase the low end torque, not increase mileage. If truck is running fine and you wanna have something more fuel efficient, get the focus.
 

·
Registered
Joined
·
210 Posts
Discussion Starter · #4 ·
Thats interesting but not entirely true, I was seeing 21 out of my 2007 4.8 CCSB 4wd I had before that was stock...
 

·
Registered
Joined
·
408 Posts
You'd be lucky to get 1mpg out of the regear. Regearing won't improve fuel economy because your RPM's will be going up as you gear down. If you go over 60 mph with 4.56 gears your going to be at 3000rpm, 4.56 will give you the low end torque for more power which is used usually for rock crawling etc. if it's a daily driver I wouldn't go over 4.10. That would give you your best mpg and power for your setup
 

·
Registered
Joined
·
706 Posts
bahndrvr said:
Thats interesting but not entirely true, I was seeing 21 out of my 2007 4.8 CCSB 4wd I had before that was stock...
OK.. i will stand corrected. I was just going off info i have heard from friends that have the 4.8. I have always gotten better mileage than them with my 5.3 and i dont drive it easy.
 

·
Registered
Joined
·
706 Posts
If and when i decide to run 35's i will regear to 4.56. But not for increased MPG. I will do it so transmission is not overworked, my RPM will be same range as stock, and increase the low end that adding the 35's takes away.
 

·
Registered
Joined
·
210 Posts
Discussion Starter · #8 ·
slw206 said:
bahndrvr said:
Thats interesting but not entirely true, I was seeing 21 out of my 2007 4.8 CCSB 4wd I had before that was stock...
OK.. i will stand corrected. I was just going off info i have heard from friends that have the 4.8. I have always gotten better mileage than them with my 5.3 and i dont drive it easy.
Thanks man, sorry if I was a bit standoffish - rough few days last week - took a migrane medication and it attacked my eyes. I lost my vision Thursday morning and actually only regained my vision this morning fully, got my right eye back by Saturday night bu this morning was first day to see out of my left eye since Wednesday night. Very scary, and I was a bit moody.
 
1 - 8 of 8 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top