Information on new truck

[teamster]

I am looking into buying a truck and pulling reefer out of Florida to mainly northeast area. I dont know much about rear ratios as it pertains to fuel mileage. I am looking at a 06 pete 379 with a 550 cat, 3.36 rears, and an 18 speed trans. Would this be a good setup assuming grossed out and running up the hills in NC, VA, and WV. Thanks for any info.

[GMAN]

Your gearing and engine should be more than adequate for the area in which you are running. You don't really need an 18 speed transmission running the East Coast but you should do all right on fuel mileage. I have a friend who has a 379 Pete and since he slowed down he is getting over 6 mpg most of the time. I believe that he runs a 500 CAT. If you keep your foot in it your fuel mileage will stink with all those non aerodynamic surfaces.

[SickRick]

That setup if pretty much more a "heavy haul" rig, than pulling reefer on the east coast. You could get by with a lot less truck. You're kind of "set" on that Pete though (and I can't really talk - I'm kinda set on a Volvo 780/500 Cummins/13 Speed myself). "Grossed Out" for a reefer is really only going to be 46K lbs of cargo (give or take, depending on gross empty weight of tractor/trailer), so you're really likely getting more "truck" than you need for the type of loads you're planning on carrying. You could do just as well with 100 less HP, and 5-8 less GEARS (to constantly have to shift UP & DOWN and UP & DOWN and UP & DOWN if you get my drift).

Then again, if you're getting a KILLER DEAL on the truck - who am I to argue? Truckpaper site shows that spec'd truck doesn't come CHEAP. It IS a sweet truck - even if not the most cost-efficient route. Again, I know how it is - I've been obsessing on my "perfect truck" though for me, it's the larger sleeper and workstation setup of the 780 that has me obsessing - since it's going to be a near full-time live-aboard situation for me.

PM me and let me know how it works out - or if you need a CO-DRIVER (heh heh).

Rick

[GMAN]

You could probably get a better deal on a little less truck. Something with about 425 hp and a 10 speed transmission with 355 rears would do well for you with the type of freight you will be hauling.

[mike3fan]

I have a 379 with 550hp w/13 speed tranny and 3.36 rears and I get 6.2mpg running max weight and running east of the Mississsppi. I would prefer 3.55's so that cruising at 65mph would run a little higher rpm, currently I run about 1200.

[GMAN]

If you are averaging 6.2 with a 379 Pete, you are doing better than most people that I have known who drive them, including myself. But mine was a 1991 and that has been some years ago. What speed to you usually travel?

[Kranky]

You could do just as well with 100 less HP

True, but it's nice to have the HP there if you do need it.

and 5-8 less GEARS (to constantly have to shift UP & DOWN and UP & DOWN and UP & DOWN if you get my drift).

You don't have to split every gear every time just because it's an 18 speed. When lightly loaded or on flat ground, just drive it like a 9 speed, but again, it's nice to have the extra splits available when you do need them.

.

[RostyC]

I usually fall between 5.5 to 6.5 mpg with my 359 depending on the load I have on. I've had more than a few tanks come out to 6.8 and once got 7 mpg. That's a B model Cat, 400hp, 18 sp, 3.90 rears. I stay at or under 65 mph.

I learned my lesson the first time taking it over 65 mph, I got in a hurry coming home from NC and cranked it up to 75 mph, I swear I saw gauge actually drop, anyway I got 4.5 mpg on that tank.

When it's time to rebuild it, I'd like to build it to six or seven hundred hp, should be able to get a little better fuel mileage.

[mike3fan]

If you are averaging 6.2 with a 379 Pete, you are doing better than most people that I have known who drive them, including myself. But mine was a 1991 and that has been some years ago. What speed to you usually travel?

Up to 65

[allan5oh]

Choosing a more aerodynamic truck will make far more difference then the right gear ratio. Besides, gear ratios can be changed.

[tracer]

I have a 379 with 550hp w/13 speed tranny and 3.36 rears and I get 6.2mpg running max weight and running east of the Mississippi. I would prefer 3.55's so that cruising at 65mph would run a little higher rpm, currently I run about 1200.

You can try switching to Low Profile tires something like 295/70R225, if you don't already use them, next time you upgrade the tires. They spin 510-512 times per mile as opposed to 495 rev/mi with regular 22.5. That might help raise your RPM at cruising speed.

510 x 3.36 x 0.73 / 60 x 65 = 1355

1355 - that would be your RPM at 65 MPH with low pro tires that spin 510 revs/mi.

Mine is the opposite problem - 550 hp with 13 speed, 3.73 rears and 512 rev/mi low pro tires - I do 59 MPH at 1350 RPM; so I"m thinking of going back to regular 22.5 that spin 495 revs/mi and would let me cruise at 1350 rpm at 60 mph.

[sidman82]

I agree with Kranky on tranny. Must have 13, 15, or 18. Don't split if you don't want. I don't know why you wouldn't. At least on top.
If you do and you know how to, it will save fuel. It's really not that hard to lift your foot off the gas to change gears.
3.36 gears good.


Mike, I have 3.55 and wish I had 3.36, wanna switch?

[BoyNextDoor]

I usually fall between 5.5 to 6.5 mpg with my 359 depending on the load I have on. I've had more than a few tanks come out to 6.8 and once got 7 mpg. That's a B model Cat, 400hp, 18 sp, 3.90 rears. I stay at or under 65 mph.

I learned my lesson the first time taking it over 65 mph, I got in a hurry coming home from NC and cranked it up to 75 mph, I swear I saw gauge actually drop, anyway I got 4.5 mpg on that tank.

When it's time to rebuild it, I'd like to build it to six or seven hundred hp, should be able to get a little better fuel mileage.

now i know this may be a bad place to put this, b/c you guys are talking about the big boy toy petes with kitty cat motors in them... but here it goes.

against the grain, I got myself an 03 Freightliner Century 120. Detroit 430/470 12.4L, 3.36 rears, 13 speed, 11R22.5 tires all around. she revs 1350 @ 61.7 miles/hour. Fuel milage? 7.76-8. I only do 61 mph, unless it absolutely has to go... or if a slower truck messe with me... lol. The truck does go 75-80 np, but i have my wallet in mind too... now i had heavy loads, and the truck pulls them to the consignee just fine. not the first there, but just fine. I go a good 1200-1300 miles on a tank of 200 gal. (btw the truck is an old CR England truck)

So if you can bear the "FreightShaker" it will leave you with a lot more money in your pocket than a pete... and you can actually fit into the doublebunk condo sleeper. I sued to drive a 378 with TMC, and boy was the sleeper a hole in the wall...

My .02 cents I'm happy making a lot of money, and keping more of it... lol

Cheers

[teamster]

I appreciate all of your responses.

[GMAN]

now i know this may be a bad place to put this, b/c you guys are talking about the big boy toy petes with kitty cat motors in them... but here it goes.

against the grain, I got myself an 03 Freightliner Century 120. Detroit 430/470 12.4L, 3.36 rears, 13 speed, 11R22.5 tires all around. she revs 1350 @ 61.7 miles/hour. Fuel milage? 7.76-8. I only do 61 mph, unless it absolutely has to go... or if a slower truck messe with me... lol. The truck does go 75-80 np, but i have my wallet in mind too... now i had heavy loads, and the truck pulls them to the consignee just fine. not the first there, but just fine. I go a good 1200-1300 miles on a tank of 200 gal. (btw the truck is an old CR England truck)

So if you can bear the "FreightShaker" it will leave you with a lot more money in your pocket than a pete... and you can actually fit into the doublebunk condo sleeper. I sued to drive a 378 with TMC, and boy was the sleeper a hole in the wall...

My .02 cents I'm happy making a lot of money, and keping more of it... lol

Cheers

That is good advice, BoyNextDoor.

[mike3fan]

I go a good 1200-1300 miles on a tank of 200 gal.

1,300miles divide by 200gals = 6.5mpg

[Part Time Dweller]

1,300miles divide by 200gals = 6.5mpg

You are obviously using the wrong calculator.

A truckers math calculator always comes up with the numbers needed to back up a story..

I had a 2001 387 w/ C16- 600hp, 18 sp, 3.36 rears on 24.5 lo pro. It got 6-6.5 mpg consistently pulling a reefer. It did a fine job running the midwest.

[BoyNextDoor]

1,300miles divide by 200gals = 6.5mpg

um... the tanks are 200 gal. never can use the full 200 gal though... more like 170-165 or so... at a 1/4 tank i can't fit more than 110 gal, so i figure the gauge is way off... but the milage calculations do add up on the ecm and on the hard fuel numbers.. lol

[Part Time Dweller]

um... the tanks are 200 gal. never can use the full 200 gal though... more like 170-165 or so... at a 1/4 tank i can't fit more than 110 gal, so i figure the gauge is way off... but the milage calculations do add up on the ecm and on the hard fuel numbers.. lol

It is a little late to be changing your story now.

First it was............

I go a good 1200-1300 miles on a tank of 200 gal.

Now, it has changed to..........

never can use the full 200 gal though... more like 170-165

You should have quit while you were ahead.

[allan5oh]

You don't understand what he said. He had two 100 gallon tanks on the truck, and could regularly get 1200-1300 miles. Keep in mind after the trip, his tanks weren't empty.