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.

 

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.

 

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

 

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.

 

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.

 

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?

 

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

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.

.

 

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.

 

Up to 65

 

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