I have recently purchased a lbz and have been surprised to be getting less MPG then with my 03 LB7.

Prior to modification I got 19 mpg runing around and 20 on a highway trip in my LB7. I have since added a 4 inch exhaust and an edge programmer normally set on economy. This now yeilds 20 mpg and 21 mpg.

My LBZ has not been modified. I have only run a couple of tanks theought it but I am getting 17 to 18 running around.

I figure the 6th speed would make up for the added EPA junk.

Those who have or have bad both, what did you find for a differnce in economy?

EGR blocker + fingerstick and ditch the cat.

Your stock mileage #'s are pretty normal for an LBZ I would think. Add a mild programmer or EFI Econo Tune - Michelin LTX M/S tires in 265's with proper pressure are likely the biggest bang for your buck. The rest is all bling and BS....'cept for maybe an H20/Meth kit..??

Egr delete has not been proven to add any appreciable mileage gains..but I would definitely do it..keep that intake clean and carbon free..How many miles on your truck (LBZ)..??


What you might do is this: Get a good heavy 8000 or 10,000lb load and go cruise up and down some significant climbs...work the motor for at least 3-400 miles. take off the load and see what happens...might be pleasantly surprised.

I run MT truck, with Michelins in a 265 size typically 21-22.5 doing 70 mph
MT truck with 275 BFG KO AT I get 19 avg hwy same speed.

Next to a real good EFI Econo tune and H20/meth kits, I believe that tires are the single most important thing for mileage gains....
Theo

28,000 miles so it is broken in. I was planning to add a tuner with an economy tune (I like my edge with attitude in the LB7). I will likely add a 4 inch exhaust as well, but I did have trouble when I installed one on my LB7. I just could not figure out how to fit the cat back on the truck:D.

The lager tire really help? It was my understanding that the 265's did not help or hurt.

My LBZ gets 21-22MPG with what you see in my sig and my LB7 gets a lil more but you'll have to give or take cause the summer is way different than the winter both drop back to 18-20 depending on how cold it is here in the south. Take into account though that I drive like a grandpa.

I went through the same thing when I went from my LB7 to the LBZ. I did the finger stick and blocker plate, exhaust, some tuning, and a few other goodies and the mileage went up. So all is not lost, just ditch the emission stuff unless you absolutely have to leave it on and then get some tuning, etc and you will be back to where you should with the new truck.

My LBZ gets 21-22MPG with what you see in my sig and my LB7 gets a lil more but you'll have to give or take cause the summer is way different than the winter both drop back to 18-20 depending on how cold it is here in the south. Take into account though that I drive like a grandpa.

X2 on that but i have a LLY with the LBZ tune. and love my mileage. 25 highway and 18-21 city depend on how many stop and goes. towing 35 fifth wheel 15.

X2 on that but i have a LLY with the LBZ tune. and love my mileage. 25 highway and 18-21 city depend on how many stop and goes. towing 35 fifth wheel 15.
so you get 25 MPG hwy with a CC dually? what hwy speeds? Because my 07 LBZ with 33" MTZs/ H2's can break 20 MPG at 70 MPH on the highway. I have a PPE standard and run the 90 HP and the 160 HP tunes depending. Either my truck is not a MPG quen like most guys on here that get 25 MPG...

90 HP PPE tune does wonders for LBZ mileage.

so you get 25 MPG hwy with a CC dually? what hwy speeds? Because my 07 LBZ with 33" MTZs/ H2's can break 20 MPG at 70 MPH on the highway. I have a PPE standard and run the 90 HP and the 160 HP tunes depending. Either my truck is not a MPG quen like most guys on here that get 25 MPG...


He doesn't do his math correctly. He tried throwing out those numbers on another post and was proven WRONG so he ran away from the conversation.
His math came up to 22mpg which still sounds like BS for a dually.

so you get 25 MPG hwy with a CC dually? what hwy speeds? Because my 07 LBZ with 33" MTZs/ H2's can break 20 MPG at 70 MPH on the highway. I have a PPE standard and run the 90 HP and the 160 HP tunes depending. Either my truck is not a MPG quen like most guys on here that get 25 MPG...

i run 60 highway and same when towing. but its a dually with the super single semi rims on the rear.

My post was incorrect I meant to Say my truck cannot Get 20 doin 70 MPH with my Setup. It makes sense now how 66 impala gets higher MPGs because he is going slower. Just Its tough to decipher 25 MPG. Maybe a SRW tuned and stock tires.

Thanks for your replies.

No drw will get 25mph period. Last time I called 66impala out on it he said his truck went 2563 miles on 114 gallons and said that was 25-26mpg and said "you do the math" Like I said before his math sucks. I can get 30 mpg coasting on a 20 mile down hill stretch but It's not safe.

X2 on that but i have a LLY with the LBZ tune. and love my mileage. 25 highway and 18-21 city depend on how many stop and goes. towing 35 fifth wheel 15.

i run 60 highway and same when towing. but its a dually with the super single semi rims on the rear.


Wait, wait, wait, hold on.......I SWEAR that I'm having deja vue right now. I'd bet dollars to donuts that I've read some crazy crap like this before.

You wouldn't happen to have used the name nitroracer1980 (http://www.dieselplace.com/forum/member.php?u=83595) in a previous [banned] forum life, have you?

You didn't happen to talk about a freak of modern engineering 2006 LLY CCLB Dually with an Edge tuned, A3K feed, 700+hp and a 10.xx second 1/4mile all while getting some ridiculous mileage claim?
http://www.dieselplace.com/forum/showthread.php?t=248044&highlight=oil+in+turbo

Yeah, I thought this seemed familiar. :ban:ed again. Bye

To the non-banned members...sorry for the further de-railment...66impala/nitroracer will not be bothering you again. Carry on. :)

I still haven't seen good milage. Haven't gotten better than 16 mpg highway or city or mixed. I'm a little disappointed. I was really hoping for better.

I still haven't seen good milage. Haven't gotten better than 16 mpg highway or city or mixed. I'm a little disappointed. I was really hoping for better.

You won't see anything better unless you make some modifications. Tuner, exhaust, maybe putting the kitty in the back of the garage... and you need the right tuner with the right tune, otherwise it could get worse. Higher tire pressure, no lift kit, stock wheels & tires... those things will help, but you've got to mix in good induction and exhaust and an economy tune.

Stock LLY/LBZ won't do much better than 16/17 unless you drive like a hyper-miler... and those guys, IMHO, tend to be nuts. I tried that for awhile and it does help... but I just can't bring myself to drive like that every day. Coasting here and there, shifting in and out of neutral all the time, slow acceleration... and consistent operational behavior are all required and will make some rather significant difference. But where's the fun in that?? :D

If you want good mileage you will have to stay with the 245's. 265's will cost you about 1.5 mpg. The truck in my sig "empty" at 75 mph averages 19.6 going from Morgan City La to Orlando Florida and back. I have gotten as good as 20 and change and as bad as 18 and change but the average is around mid 19's. Cruising at 55 it will get 22-23 ( and has) but I rarely drive that slow. I use a Hypertech but I am sure that any "name brand" will probably give you similar results. A lot of people here disagree but I don't think you need to change your exhaust unless you are going for big power gain's, the stock exhaust flows well enough without the cat for cruising at hiway speeds. Have a good day.

My tire pressure is 55 up front 60 out back. 265 michelin ltx a/t. I get better milage driving secondary roads to work and back every day at 55 - 60 mph than I do on a divided highway with the cruise set an 65-70mph. I come from the gasser world. 97 chev 1/2 ton 305ci. 2wd xcsb. Best milage I ever got was down I75 to florida from ontario with the cruise set at 90 mph. Ya 90.

My tire pressure is 55 up front 60 out back. 265 michelin ltx a/t. I get better milage driving secondary roads to work and back every day at 55 - 60 mph than I do on a divided highway with the cruise set an 65-70mph. I come from the gasser world. 97 chev 1/2 ton 305ci. 2wd xcsb. Best milage I ever got was down I75 to florida from ontario with the cruise set at 90 mph. Ya 90.

Keep in mind that unless you've recalibrated, running larger tires will throw off your odometer... which means you're getting better fuel mileage than you think.

Wait, wait, wait, hold on.......I SWEAR that I'm having deja vue right now. I'd bet dollars to donuts that I've read some crazy crap like this before.

You wouldn't happen to have used the name nitroracer1980 (http://www.dieselplace.com/forum/member.php?u=83595) in a previous [banned] forum life, have you?

You didn't happen to talk about a freak of modern engineering 2006 LLY CCLB Dually with an Edge tuned, A3K feed, 700+hp and a 10.xx second 1/4mile all while getting some ridiculous mileage claim?
http://www.dieselplace.com/forum/showthread.php?t=248044&highlight=oil+in+turbo

Yeah, I thought this seemed familiar. :ban:ed again. Bye

To the non-banned members...sorry for the further de-railment...66impala/nitroracer will not be bothering you again. Carry on. :)

Gotta love IP banning. :)