[benjames]

I'm sure this has been discussed many times but I am looking at an 04 379 Pete the previous owners claimed that they only got 3.5 mpg.
Is there any hope of doing any improvements to this truck to help mileage?
As far as I know it is completely stock and has been overhauled.
The setup is pretty decent 13 speed with 3.55 rear
Thanks

 

[8 axle lowmax]

I'm sure this has been discussed many times but I am looking at an 04 379 Pete the previous owners claimed that they only got 3.5 mpg.
Is there any hope of doing any improvements to this truck to help mileage?
As far as I know it is completely stock and has been overhauled.
The setup is pretty decent 13 speed with 3.55 rear
Thanks

Yes, absolutely. There is tons of info on doing this out there, although some of it has been deleted in a different forum due to legality concerns. But here, I believe we can discuss it with no problem. I have an mbn, and had to learn all about it too. They are not a bad motor, but cat made changes to them which cause them to not be as good as they could be, or as good as the older C15's. You can get the ecm reflashed to an older file, it should improve hp, mileage, and just make it sound and run better. If you do this, you may need to look at some other changes to go along with it, an upgraded turbo, non-catalytic mufflers, to name a couple. There is a member by name of Mr Haney who is quite expert at these mods and could provide you with the needed info. Good luck.

 

[jr cat mechanic]

well

what was he hauling cows,equipment,car trailer that engine should get around 6 to 7 being max according to what they used it for,great setup ,remember on a cat going thru gears if empty skip a couple of gears get into high as soon as possible ,1500 to 1550 is ideal for cruising speed in 13 th gear,let me know what type of trailer you will be pulling,keeping that gap between sleeper an trailer as close,reefer or van. as possible.does it have air fairings

 

[Mr. Haney]

The MBN never got good fuel mileage not matter what type of work they did in comparison to a 6NZ 550 doing the exact same work. Why? Poor injection timing in the timing tables of the programming. Catalytic converters in the mufflers caused high exhaust restrictions. These are the 2 biggest culprits, but they can be made to get good fuel mileage while producing good Hp too

 

[jr cat mechanic]

well

worked on several ,dont remember seeing a converter on these ,by any manufactures,ran several 500 hp on dyno,with fan an A/C ON putting 465 to 475 out to wheels.cat says 80% to wheels ,so a 500 would be 450 ,also what HP is this engine, when operating this engine if you are operating in say 1200 to not over 1800,have set to 1800 rpm on rating #some flashes have 4 selections in them ok ,you can flow the fuel,need dyno & cat dealer ok,high flow mufflers from pittsburg power ,straight pipes

 

[dbennett48]

Your numbers are incorrect jr cat. 80% of 500 = 400.

 

[jr cat mechanic]

well,yes .bump wrong key ,sorry ,but cat info dead on good buddy

 

[SledMan]

worked on several ,dont remember seeing a converter on these ,by any manufactures,ran several 500 hp on dyno,with fan an A/C ON putting 465 to 475 out to wheels.cat says 80% to wheels ,so a 500 would be 450 ,also what HP is this engine, when operating this engine if you are operating in say 1200 to not over 1800,have set to 1800 rpm on rating #some flashes have 4 selections in them ok ,you can flow the fuel,need dyno & cat dealer ok,high flow mufflers from pittsburg power ,straight pipes

All MBN's and most Acerts I have seen have the CC mufflers. It's all part of emission reduction that Cat started with the MBN. As Kurt stated along with retarded timing make poor mpg and run like a pig.

 

[jr cat mechanic]

well

thats the reason for getting a par dyno run ,adjusting the FLS=FTS ,CHANGES TIMING AN FUELING,mbn serial # is a bridge engine never seen a catylitic converter on one from factory ,companies usually installl ,acerts yes they do,MBN WILL DO FINE ,FIND A CAT MECHANIC OK ,THATS ALL YOU NEED ,REMEMBER YOU CAN PUT CAM ,TURBO ,INJECTORS ,ALL THE AFTER MARKET PARTS YOU WANT ,DONT MEAN A THING ,NEED SOMEONE WHO KNOWS WHAT THEY ARE DOING,TO MAKE IT ALL WORK,DONT WASTE YOUR MONEY ,GET A PAR DYNO ,SET AS HIGH AS CAT WILL LET IT GO,THEN REPOST OK ,YOU WILL STILL HAVE MONEY LEFT OVER

 

[SledMan]

thats the reason for getting a par dyno run ,adjusting the FLS=FTS ,CHANGES TIMING AN FUELING,mbn serial # is a bridge engine never seen a catylitic converter on one from factory ,companies usually installl ,acerts yes they do,MBN WILL DO FINE ,FIND A CAT MECHANIC OK ,THATS ALL YOU NEED ,REMEMBER YOU CAN PUT CAM ,TURBO ,INJECTORS ,ALL THE AFTER MARKET PARTS YOU WANT ,DONT MEAN A THING ,NEED SOMEONE WHO KNOWS WHAT THEY ARE DOING,TO MAKE IT ALL WORK,DONT WASTE YOUR MONEY ,GET A PAR DYNO ,SET AS HIGH AS CAT WILL LET IT GO,THEN REPOST OK ,YOU WILL STILL HAVE MONEY LEFT OVER

Not sure if I should waste my time arguing with you or not, as you seem to know everything. No Cat MBN program will give you decent power and mpg...period. The file needs to be flashed with an early 2WS/6NZ file to gain power and mpg. The bridge files have retarded timing and poor fuel tables as Mr Haney said.

The CC mufflers come with the bridges... Unless they were removed before you saw them.

 

[SledMan]

thats the reason for getting a par dyno run ,adjusting the FLS=FTS ,CHANGES TIMING AN FUELING,mbn serial # is a bridge engine never seen a catylitic converter on one from factory ,companies usually installl ,acerts yes they do,MBN WILL DO FINE ,FIND A CAT MECHANIC OK ,THATS ALL YOU NEED ,REMEMBER YOU CAN PUT CAM ,TURBO ,INJECTORS ,ALL THE AFTER MARKET PARTS YOU WANT ,DONT MEAN A THING ,NEED SOMEONE WHO KNOWS WHAT THEY ARE DOING,TO MAKE IT ALL WORK,DONT WASTE YOUR MONEY ,GET A PAR DYNO ,SET AS HIGH AS CAT WILL LET IT GO,THEN REPOST OK ,YOU WILL STILL HAVE MONEY LEFT OVER

You set a MBN on a Cat dyno for a PAR report and the first thing that's going to happen is they'll flash it to the latest software for that engine. It'll run like a pig, and maybe get 4.5 mpg no matter how you drive it. Been there, done that.

 

[benjames]

Thanks for the replies. I haven't bought the truck yet, but if I can make it a better mpg truck and don't have to do everything all at once all is good.
What kind of mileage do you think I could get. I will be pulling flat bed (if i didn't mention that before).
Mr. Haney when you have time to chat about this truck PM me your info I can't pm yet.
Thanks

 

[bmoeller]

I've been running an MBN in a W900L w/ 72" Areodyne sleeper, pulling a 53' spread axle bullrack, for almost 7 yrs. 13spd and 3.55 gears and 24.5LP rubber. Mine had been uprated to the 525hp file before we got it. If that one still is set at 475, get it uprated! Just make sure it is NOT a lo Nox file!

Never did see any real mileage gains, or any power increase pulling the cat mufflers off. (They pretty much look like a regular muffler, but can't see through them. Not to mention VERY heavy!!!!! Bet you can lose almost 100# or more (mine had 2) yanking them off.

Best thing I ever did to mine, so far, was a 150ohm resistor in the fuel temp harness and increasing the fuel pressure, via stretching the spring in the fuel transfer pump and replacing the tired fuel pressure bypass valve and a new fuel supply pump. The spring mod alone almost eliminated most of the turbo lag. No longer lethargic. Once it hits 10spi boost, it about pegs the boost gauge right away.

The motor IS capable of good mileage. Especially before the ULSD came out, I was getting 5-5.9mpg pretty regular. And still get 7-7.5 with a hopper bottom. The sweet spot with the motor is ~1425RPMs, which puts you about 65-68mph on the big road. I'm more in the 4.2-5mpg range with the 'rack now. Lost .3mpg with ULSD alone. :/ Having over 800k hard miles on it probably isn't helping. But, I also need to replace the injector harness. It is leaking oil through and causing a problem. Whenever I clean the connector up with electronics spray, it runs smoother and get my mileage back.

The holes in the injector tips are quite large, so they won't atomize the fuel as well as they could.

Also, if the electronically controlled wastegate solenoid is acting up, you'll have problems there as well. Mine is giving me fits. Still haven't gotten the ECM reflashed with a 6NZ or 7CZ file to bypass it.

Wouldn't be surprised if the head and/or turbo needs to be replaced either.

With you pulling a flatbed, you should be able to get 5.5mpg out of it. If not, something is wrong, or you have a heavy foot.

Make sure to put quality fuel in it. Mine is picky. Running Lucas fuel additive through it a few times a month to keep everything clean helps considerably.

 

[jr cat mechanic]

dont know everthing ,just amazed how much truck drivers know,really amazed,how long do you have to drive a truck to become a good mechanic, real mechanics are in high demand ,go by cat dealer get job app ,you will do fine

 

[jr cat mechanic]

worked on several ,dont remember seeing a converter on these ,by any manufactures,ran several 500 hp on dyno,with fan an A/C ON putting 465 to 475 out to wheels.cat says 80% to wheels ,so a 500 would be 450 ,also what HP is this engine, when operating this engine if you are operating in say 1200 to not over 1800,have set to 1800 rpm on rating #some flashes have 4 selections in them ok ,you can flow the fuel,need dyno & cat dealer ok,high flow mufflers from pittsburg power ,straight pipes

my math off on 80% of 500 ,its 400 ,everthing else dead on

 

[jr cat mechanic]

certified cat 1989,make a very good living ,fixing what know it alls screw up,action resources,robbie d wood,western distribution,just to say a few ,that did fine with MBN

 

[SledMan]

dont know everthing ,just amazed how much truck drivers know,really amazed,how long do you have to drive a truck to become a good mechanic, real mechanics are in high demand ,go by cat dealer get job app ,you will do fine

I guess I fall under both categories. I've had a fleet of trucks for over 20 years. Done ALL the work on them. Everything except paint and body. Attempted that once and quickly figured that's best left to the body shops. I've learned a lot in those 20+ years. And yes, my local Cat dealer actually did offer me a job once. Just couldn't give up the good life, you know? I mean who in they're right mind would give up 3am phone calls, sick whiney azz drivers, payroll, no time off????

 

[Mr. Haney]

worked on several ,dont remember seeing a converter on these ,by any manufactures,ran several 500 hp on dyno,with fan an A/C ON putting 465 to 475 out to wheels.cat says 80% to wheels ,so a 500 would be 450 ,also what HP is this engine, when operating this engine if you are operating in say 1200 to not over 1800,have set to 1800 rpm on rating #some flashes have 4 selections in them ok ,you can flow the fuel,need dyno & cat dealer ok,high flow mufflers from pittsburg power ,straight pipes

A Pittsburgh Power muffler is actually a Donaldson pat # M100463. You can buy it online from Ryder Fleet Products for a lot less money than PP will sell it for. The next time you're working on an MBN go and pull up the part number and costs of replacing the stock muffler. Don't be surprised at the pricing, but at least you'll know that it isn't a standard muffler any longer

thats the reason for getting a par dyno run ,adjusting the FLS=FTS ,CHANGES TIMING AN FUELING,mbn serial # is a bridge engine never seen a catylitic converter on one from factory ,companies usually installl ,acerts yes they do,MBN WILL DO FINE ,FIND A CAT MECHANIC OK ,THATS ALL YOU NEED ,REMEMBER YOU CAN PUT CAM ,TURBO ,INJECTORS ,ALL THE AFTER MARKET PARTS YOU WANT ,DONT MEAN A THING ,NEED SOMEONE WHO KNOWS WHAT THEY ARE DOING,TO MAKE IT ALL WORK,DONT WASTE YOUR MONEY ,GET A PAR DYNO ,SET AS HIGH AS CAT WILL LET IT GO,THEN REPOST OK ,YOU WILL STILL HAVE MONEY LEFT OVER

A PAR dyno run on an MBN is a waste of time and money in my opinion. But I'm a washed up truck driver/owner that hasn't been successful at working on my own truck at all. But here is a video of what can be done with an electronic CAT engine in my hands. Yes I'm like Shultz from Hogan's Heroes "I know nothing"

http://www.youtube.com/watch?v=Qv9rLMHZe-4

1592RWHp. When the dyno operator stuck his foot in the throttle it was already building 900RWHP @1800RPM. I bet you don't have the knowledge to do that, DO YOU???????????

You have only been taught what CATERPILLAR wanted you to know. Trust me there is a lot more to know then that. LOL

dont know everthing ,just amazed how much truck drivers know,really amazed,how long do you have to drive a truck to become a good mechanic, real mechanics are in high demand ,go by cat dealer get job app ,you will do fine

This is a condescending remark towards all truck drivers. It shows me how little respect you have for them. Remember that the next time your wife sets dinner on the table and you pull up a chair to eat it. If you or she bought it, a truck has brought to the place where you purchased it from. Next time your hungry start a garden and butcher a steer. You may want to think a little bit more about your comments about what you think of a truck drivers before you post negative comments about truck drivers on a trucking website. From this comment were all stupid in you mind, but are arrogant know it alls.

certified cat 1989,make a very good living ,fixing what know it alls screw up,action resources,robbie d wood,western distribution,just to say a few ,that did fine with MBN

Damn look at my response above, you actually confirmed what I gleaned your opinion of use as a group of individuals was in this post. Certified CAT technician since 1989. WOW I'm impressed with that. And I still bet you can't figure out how I got my electronic powered CAT truck to dyno 1592 Hp in a competition. One a different day it dynoed 1606RWHP. Do ya wanna know how???? LOL Or does your CAT trained knowledge know how to do it? By the way that is 1 year old Taylor Dyno that was calibrated before the contest for accuracy

Maybe you should figure out how this truck is producing so much power with an electronic CAT C-16 engine too? Another truck driver that never worked for a CAT dealer or is CAT certified technician. Again it proves my theory........all CAT techs are only taught what CAT wants them to know. You need to step away from the CAT brainwash technology they feed you on a daily basis and think outside of the CAT yellow box they have trained you so diligently to stay in. Yea us dumb truck drivers are know it alls. (SARCASM!!!!!!!)

http://www.youtube.com/watch?v=yCiLJlQ_SgE

More Hp than you can comprehend from a bone stock C-16 short block and a CAT 70 pin ECM

 

[jr cat mechanic]

know how,they being EPA control us now,will that truck pass emissions,we have to conform to the epa standards first ,formost,built many that were very very impressive ,cat makes all the parts to do it ,marine cams ,turbos,just EPA,alot of the driver technicians turn fuel to one ,before they actually know what is wrong,seen pittsburg power boxes put on ,covers up original problem ,but it all ways shows it ugly head,now repair is costly ,nothing against a hot rod ,c-16s with 2000 hp ,is easy ,problem EPA, I NEVER REALLY NEEDED HELP FIXING AN ENGINE ,STILL DONT

 

[jr cat mechanic]

know how,they being EPA control us now,will that truck pass emissions,we have to conform to the epa standards first ,formost,built many that were very very impressive ,cat makes all the parts to do it ,marine cams ,turbos,just EPA,alot of the driver technicians turn fuel to one ,before they actually know what is wrong,seen pittsburg power boxes put on ,covers up original problem ,but it all ways shows it ugly head,now repair is costly ,nothing against a hot rod ,c-16s with 2000 hp ,is easy ,problem EPA, I NEVER REALLY NEEDED HELP FIXING AN ENGINE ,STILL DONT, ANYONE CAN BUY A BIG BOSS ECM, GETTING ALL THAT HP ISNT THE PROBLEM ,ITS RELIABILITY AN SERVICE,