Who has the best mpg ?? Specs please!

It would probably help to describe the type of cargo you haul, typical weight, terrain you run across, and all those variables that go into speccing a truck.

 

It's not what i got but a t600 kw with 12.7 det 13spd and 3.55 rears sounds what u looking for that combo would knock down easy 6 mpg setup or a 6nz cat but the cat will cost more in getting then a detroit powered truck will cost. Could do freightliner but wiring harder to work on and cabs are noisy. Just my 2 cents and what I've seen.

 

14l-det series 60- 475-13speed eaton-2.93 rear- Firestone m726el drives- Michelin steers- 105-110 all around. Usually around 74-76k- route CA-NJ- average around 6.4 ish... Factor in heavy winds and it starts to drop dramatically.

 

Every engine has an EPA sticker that tells you how many MM3 of fuel it takes to make the advertised HP.
Freightliner wiring, you peal back the covering and look at the number, look in the book, it tells you the exact length of wire where it comes from and were it goes to, and what size it is.

 

Just looked at an 06 classic today. Nice truck with a 515hp 14L detroit. Had that problem with the turbo huffing and cutting out though, and some idiot decided that the jake needed to be on a separate switch on the floor like the old style high beam button. Only wanted $28k but no thanks.

This old oil spewing thing is back to getting close to or over 7mpg with an N14, 13sp, and 22.5 tires. Not sure what the rear end ratios are.

I agree, 6mpg is easy with a t600. Last t600's I drove were full height with 475 cat c-15's and auto 10's. Mine got 5.9 at the worst, 7.1 pulling new wabash trailers with the skirts. Also had 22.5 super singles. That was at 65. One of them was limited to 72 and averaged 7.3. That was with the engines turned down by some idiot in the office.

The t600 I drove for Arrow was a mid roof, 425 cat, 10 speed, limited to 70. That one averaged 7.5 or better the whole time I drove it.

 

My 1999 FLD120 had 12.7 Detroit, 10spd and 3.90 rears. At 60mph i would avg 7.5mpg pulling a van trailer and this was with a flat-top truck dragging 5' of trailer in the wind. When i switched to dry bulk I went to 8mpg avg. Should have never sold the dang truck

 

####, just think what it would have done with that bully dog kit on it.

 

I think the thing to keep in mind is that you want an aero truck no matter what manufacturer you go with. Engine rating would be somewhere around 400-450hp with a 13 speed. Rear end in the low 3's should maximize that hp and keep the engine in a good rpm range. Tire size is 22.5's and road speed around 58 to 62mph. Just my opinion, but this setup should be good for 75k lbs while maximizing fuel economy. Also, a midroof may be your best bet for versatility.