2006 387 MPG Results
 

Ok, so I figured I would start a thread with my different MPG numbers for the new truck.

I run a dedicated lane, 4,500lbs down and empty back in a J&L Dry Bulk tank for roughly 2,700 miles round trip. My route never changes and it goes as follows:
Westville, IN (US421 to I-94 to I-57) to Tuscola, IL. Then from there I take I-57 to I-55, I-40, I-30 to Texarkana then AR549 to US71, I-220, I-20 to US79 to US59 thru Houston to Victoria then TX185 to Seadrift.

On my 1st trip this week I set my cruise at 1,350rpm which put me at 67mph. I got fuel and avg 7.2mpg for the trip down.
On the way back, i set my cruise at 1,250rpm which was 62mph and I avg 7.85mpg.

Next week i am going to set it at the 1,250rpm down loaded and see if it makes a difference with the 4,500lbs in the tank, which i doubt it will, but ya never know.

Since you run the same route with the same freight, I'd do a week at each RPM, then use the average for that week as the MPG for that RPM. Even though minor, things such as the wind, temperature and humidity will affect the MPG's. Just an idea, anyway.

Yes, thats my plan...next week will be at 1,250rpm for the entire trip. Then the following week will be at 1,350rpm for the whole week, then I'll go 1400rpm (70mph) in the states I can go 70 in, the others will be at the 67mph setting

So, what's the point? What are you trying to find out? With that kind of weight, you don't need to worry about pulling power. You want better MPG, you run between 1250-1300 RPM. In your case it's 62-64 mph. You want to drive "faster", you'll have to pay for it. That simple. Have fun tho...

in new zealand you could tow that weight behind a 4+4 ute and get 10ks to the litre,just a thought

I just was seeing what the benifits were to driving slower compared to faster....or in this case, if things keep up this way, it will cost me $100 a week to go 4mph faster. Just was shocked at the idea was all. What can I say, i get bored doing the same damn thing each week LOL

I hear you....

Not to mention i did plan on doing some mods such as Pittsburgh mufflers, and maybe a PDI ECM and figured with my run being the same, I could post some REAL WORLD numbers up as I go along.

Just for fun, ask any Pete dealer, how much is your muffler. I was thinking about the same thing, or Walker Noise-breakers, but it might be illegal emission wise.

I will do that tomorrow as the truck is going into the body shop to have the hood hinges replaced as they are bad (and the dealer is covering the total cost!)

I know my truck is not CARB compliant, so it keeps me out of CA anyways, but that's fine with me as I don't like going there. The Pitt mufflers are $275 for my truck a piece... but their same muffler that is 10" shorter, but the same width is $189? Since I'm going to replace the top of the stacks anyways, I think I'll go with the shorter muffler and a longer top stack (tyes it will fit, I measured) so the tops will be basically free! And the are 50 states legal!!!!!!!!!!!!!!

"Our new performance muffler solution for the 387

This muffler uses a acoustic louver sound dampening

This muffler is noticeably louder than our Quiet Performance muffler

Up to 50 additional horsepower and improved response

Lower exhaust gas temperatures

Fast return on investment and easy fuel mileage gains

Extra heavy duty construction. "

They are legal noise wise, but i was talking about emissions. CAT ACERT suppose to have catalytic converters in it. I was quoted $2500 each(i've got 2) at KW dealer.

Why not just buy the donaldson 1000463 for $70.00 from ryder fleet products online? same as the p.p, one. straight thru design without the loud noise. http://www.ryderfleetproducts.com/ry...oductDetail.do

Because the DOnaldson one is only 9" wide, and mine are 11" wide. Unless I want to spend the money for someone to make a custom mounting set-up, I'm stuck with the 11" wide mufflers due to they mount to the truck AROUND the muffler, and the brackets would be too big for a 9" muffler.

I have no idea what you are talking about here....this is my 2nd ACERT CAT enigne and none of them had catalytic converters on them. And the Pittsburgh mufflers are 50 state legal EMISSIONS wise as well.

S.H.C. I am like you on the m.p.g. I document the mileage at every stop & every fill up. I know the wind, hills, weight, e.t.c. have a lot to do with the different m.p.g we get, but I want to keep track to see too what is the optimum speed,rpm to get the best m.p.g. without lugging the engine or going ridiculously slow. I also keep tabs on my m.p.g. to help me determine if anything may be needed such as time for overhead run or cac leaking. these can affect m.p.g. I had a great tailwind pushing me down i-65 last week. got 7.0 mp.g. had to recalculate 3 times to make sure I added the numbers correct. some may think different on this, but I have always put 5 lbs more air in tires than posted on sidewall. all mine show 105 psi. I put in 110 psi. none of them stay at 110 in the cold weather, they all drop over time. keep on experimenting with your m.p.g. & any other truck related info. it will be of use to someone.

That's why i've said ask your dealer. My truck is 2005, actually maid in may 2004, and engine february 2004. If it has no converters, why is such price? I'm trying to figer this thing out, let me know what did you find out....

https://dynamic.donaldson.com/webc/W...210&item=21897

Still only 10" wide, plus it's 51" long...mine is 62.5"

I asked them today and the parts guy thinks you are talking about the resonator under the cab. Some call it a convertor, and mine was $875 to replace. Mine has this resonator and then 2 mufflers on the stack, so I asked them how much louder it would be if I just bought spools and removed the mufflers, and he said maybe 20dbl? Since the convertor/resonator is the main sound deadner, so i may just go thay route too..... aparently most KW's that have the stack out the rear (like mine) such as a T600 or T2000 doesn't have mufflers, but pete's do....guess to be more costly LOL

Are you sure it will ONLY cost $100 a week? That seems a little low to me after all thats only 25 gal. I'm just wondering. You get bored doing the same thing every WEEK? I do the same 3 roads every NIGHT! I watch the pot holes age!

I was guessing at the cost....but 7.2mpg for 2700 miles is 375 gal @ $3.50 a gallon is $1,312...... 7.85mpg is 344 gallons for a total of $1,204, so roughly $100 a week to go 4-5mph faster for the whole trip. Now, going 67mph for 2700miles nets me 40.3hrs of non-stop driving (which nobody does LOL) and 62mph gets me 43.5hrs of driving. So for 3 more hours on the road, I'd make an extra $100. And with the price of stuff today, looks like it's gonna take me an extra 3hrs!

The mufflers is under bunk on mine....

http://i6.photobucket.com/albums/y21.../DSC000252.jpg

Yeah, I have the one under the bunk, then 2 in the back. One on each stack :c

What year is your truck? Maybe one is a regeneration system seeing the only trucks I know that have 2 under the cab are 07+ emissions motors. Is that it?

What engine/transmission/rear-end combo are you running in that truck? I'm somewhat surprised that you're getting better mileage at 62 than at 65. For me, it was the opposite... then again, that was a computerized governor, not the sole of my right boot doing the governing.

C13 @470hp/Eaton 13spd/3.36 rears

well, this last week was a bust. I had STRONG headwinds for about 200+ miles of my trip to Texas. I wound up getting 6.75mpg going down set at 62mph.

My trip back home was the same headwind for 200+miles, then nothing. I fueled in MO and was at 7.25mpg set at 65mph.

Looks like this is going to take some time, but I will admit, at 65mph (1325rpm) the engine seems to run smoother and pulls hills much easier.

The truck is currently at peterbilt having the shift-tower busings replaced (stick is sloppy as could be) and having the overhead ran since I'm sure it has prob never been done, and at 517k miles, I figured it was a good time for it. I'll update next weekend if it has improved at all.

I also am looking at going straights on the rear, and leaving the factory resionator/muffler underneath and seeing how that does, then might measure it up and see if I can get a high-flow replacement for it on down the road :smokin:

great thread, lots of good methodology and business thinking in here. Better than $30 an hour paid to you for 3 extra hours on the road...

Thanks, like I said, I get bored with my run and this gives me at least a little something to do in the meantime. And the 3 extra hours is saying you were to get up at say 5am and drive for 11hrs w/o stopping AT ALL. And we all know we need oour coffee, bathrooms and leg breaks, so really it just lowers it to about 1.5hrs less. With my run, I leave Mon morning at 7am and I'm back home in the garage by noon thursday going 60-62mph. Not too bad if I might say to make an extra $100 each week to spend on something better than fuel ;)

Personally, if I had pipes behind the sleeper I'd go to single straight. Less weight and less wind drag.

But then it would like every freightshaker-volvo-IH out there LOL....I like the duals and none of it is exposed to cause wind-drag since I shortened the stacks to roof level ;)

This week was a bit different. I set my cruise at 65mph (1,325rpm) for the entire trip. The wind was calm and not much stop-n-go this week. I avg'd 7.25 loaded and empty both ways. The truck ran smoother, I was able to stay ahead of most company trucks (JB, SNI, Werner, US EX) and made average time.

I think this is where I'm going to run the truck at for the next few months and start doing my upgrades...... first will be a 3 axle alignment to see if it makes a difference (plus who knows if it has ever been done) then I'm going to get the new mufflers, then have the overhead ran. After that, I'm going to try a few other things such as a ECM tune and a few online things I have read for the C13.

The good rule of a tumb;-If it's not broken, don't fix it! Of course i didn't mean scheduled maintenance intervals....

I know what you mean, but the mufflers have 520k on them now, the overhead should be done every year along with a 3-axle alignment. If I do a ECM upgrade, it won't be for at least a year, and the rest I am still 'iffy about.

I'm very particular, where i do alignment, and overhead. And definitely wouldn't mess with ECM unless i have to....

I have my alignment done at the local Goodyear dealer and my overhead will be done at Great Lakes Peterbilt

Just an update....I have been averaging 7.25mpg with the truck and am not very happy. I honestly thought it would do better since I run empty everywhere I go, and I keep it under 65mph.

That being said, today I did a mod I heard about with the fuel wire, and also my boost wire going to the ECM. The truck deff idles much smoother, and the throttle response is great. I don't think i will gain any MPG yet, but I will check it out on this weeks run.

Next weekend I am removing the resionator/convertor and putting in a piece of straight pipe, thus eliminating one issue. I have been told that I should gain about .3mpg with that, then going to replace the mufflers on the back with some Donaldson high flows and see how she does. If i can even gain .5mpg total I will be very happy!!!

You are getting about all you will ever see with a Cat, just how it is, the Cats are NOT fuel mileage engines,never were, just ask anybody that has one,

Also notice most big fleets didn't use Cats,even when they were available, there is a reason and fuel mileage is the biggest one.

True.....but I've never pulled 4500 lbs with it either so I wouldn't know. OMG that is light. Seems like overkill to me. I bet my little M11 would get 9 mpg on that run.

I bet it would too!!!! I went with the C13 hoping it would help out a bit, and it deff is better than a C15 would have been.

As for being light, I love it till winter comes around. Then it is a nightmare to deal with. Heck, even on a dry day I lock up the trailer tandems just rolling at 25mph and stopping. Scares the carp out of the 4 wheelers if I have to brake quick on the interstate. All that smoke tends to make them go for the median LOL

I'm not so sure, there are a few guys I run with who have 05-06 C15's in W9's and with the resionator removed and donaldson mufflers that are getting 7.5-8mpg pulling liquid tanks heavier than me.

I'm just kicking myself in the ass for getting rid of my old trusty FLD. I should have just spent the $2000 on the clutch and hit the road, but as usual, I had to make an impulse buy LOL