MPG,semi-pickup's

[nlemerise]

I drive a Catepillar C13 with 360 hp and average almost exactly 7 MPG...drive right around 60 MPH and this is through the mountains of northern Nevada and California (lots of elevation changes). If I had an engine about half the size of the 7.3 in my pickup truck and the right torque curve and enough gears to drive it at 60 MPH at 1400 rpm, I bet the mileage would be phenomenal...problem is, it wouldn't get out of its own way...too slow accelerating. The truck buying public wouldn't put up with a pickup that accelerated like a semi.

[SANDDEMON08]

Good point

[tjc transport]

Originally Posted by rob_nc

Sounds like you've got 4.64 rears. What do you haul that requires this heavy of a truck?

it is a triaxle dump truck.

[tjc transport]

Originally Posted by poppie

................. 2 1/2-3 mpg, Is that all city/urban driving?,when I was hauling stone for sewer job's in a day cab Mack @ 70,-75,000 #'s the ole girl got 5-5 1/2
,.

same here poppie. my old tandem with the 237 and mud stick trans had a top speed of 57 mph, but got 5 1/2-6 mpg all day long.
ain't nothing like an old mack truck.

[poppie]

Originally Posted by tjc transport

same here poppie. my old tandem with the 237 and mud stick trans had a top speed of 57 mph, but got 5 1/2-6 mpg all day long.
ain't nothing like an old mack truck.

............It was an R 600,1972 tractor,had the square fuel tank's and wet kit,also used it to haul the case 888 or case 9030B excavator's on a 48 ft drop deck,no AC,hotter than hell in the summer time.

[tjc transport]

i hear that !! my tandem was a 79 DM800.
my tractor was a 74 rd 600 with the same 237 mud stick combo.
the tractor was totaled in 94 when a car hit it head on doing 80+mph. it was sitting on the side of the road with the goose-neck of the lowboy trailer on it. lucky for me, i was unloading a D-8K at the time, so i was not hurt when it hit me.

the 79 DM was sold to a contractor that wanted it for the better part of 10 years when i got the 2004. it sold for way more than it was worth, and the last i heard it is still on the road in central Pennsylvania running sand to a pool company.

[rbaker6336]

Originally Posted by poppie

................. 2 1/2-3 mpg, Is that all city/urban driving?,when I was hauling stone for sewer job's in a day cab Mack @ 70,-75,000 #'s the ole girl got 5-5 1/2 running I- 90 from the pit at beverly & I-90@ Elgin Il to the Schumberg I-90 & 53 area,aprox 40 mile's or so and that was with ,at that time,a 28 year old hunk-o- junk with a 237 and a 5 speed,the ole girl was flat wore out!!!!!!!.

I had a variety of tri-axle dumps running in the flat lands of Fla with from 290hp to 444 hp(upgraded to 465) they were cummins 855 and L10 and cat 3306 and 3406
all had 40k to 46k lb rears with ratios from 4.11 to 4.30 and 4.56 and 8LL transmissions
all exceppt the 444 averaged 6 to 6 1/2 mpg grossing 68k to 85k lbs and most would barely top 7 mpg empty
the 444 averaged about 7 to 7 1/2 mpg
one marmon with L10 cummins and 4.11s would get 10 mpg empty

[oltrucker]

my lastbig truck had a 550hpcat E engine and it got about 6.5 mpg moving 80,000 gross sheet rock on a flat bed,,,my first truck was a 318 hp detriot and it was lucky to get 3 mpg at 73,000 gross.

[natewoz]

2000 KW T800, C12 10 spd, 3.70 gears 22.5 tires. 3-4 MPG city work at 80,000#. Best ever was a run from Minneapolis to Chicago and back shuttling empty walking floor trailers, about 32,000 # and I got nearly 9 MPG. My old F150 pulling a fishhouse loaded with stuff got about 6 MPG.

I would love a Eaton Fuller 13spd and a stout rear in my pickup with a properly matched engine. With a 7.3 and 3.73 gears and factory tires, you could have your choice of some great reduction and overdrive gears to select depending on load and conditions. Ah, if Ford only built trucks for real drivers....

[rbaker6336]

Originally Posted by natewoz

I would love a Eaton Fuller 13spd and a stout rear in my pickup with a properly matched engine. With a 7.3 and 3.73 gears and factory tires, you could have your choice of some great reduction and overdrive gears to select depending on load and conditions. Ah, if Ford only built trucks for real drivers....

personally I always liked a 5x4 better

[natewoz]

I got to edit my previous post, 3.73 would give you some nice reductions but not much of an overdrive. I got to figuring the approximate ratios, and 13 speed and 3.73's with about 32" tires would give a slight reduction from a 4r100, I figure you'd be spinning (very roughly) somewhere around 2300-2400 rpm at 70 mph- If my math is right. A gear ratio higher like a 3.08 or so could show some definate benifits on both ends of the range, you'd be pulling about 1600 at 70 mph.

I love the split gears on the 13's for hills and especially city driving in heavy traffic, not as much shifting to do. Super tens are pretty nice, but all the splitting gives me a sore wrist after a while. I've never seen a 5 and a 4, sounds like itwould take some getting used to.

[rbaker6336]

the 13 OD had .80 in overdrive and the 13 OOD had .62 in overdrive,they aren't bad transmissions if going forward all the time,but being in construction were just too slow in reverse
the double OD was a little faster in reverse

[tjc transport]

ahhhh. the old quad box. there is only one thing better than a quad. and that is a quad box, with a 5 speed auxiliary behind it, or maybe a 5X5X5. that is a 5 speed, with a 5 speed auxiliary behind another 5 speed auxiliary.

nothing like trying to moving a 500 ton load, and having to shift 20 times to get to 5 mph.

[TINY]

I drive a 2005 freightliner columbia day cab. we pull reefer trailers, and empty weights of around 35,000 pounds. i probably shouldn't say it, but when loaded we are sometimes advised to avoid weigh stations because we are grossly overweight.
however, we average 5.5 to 6 mpg throughout the fleet. mostly day cabs, and about 5 sleeper trucks. 10 speeds in all, just a standard detroit engine. when we got these trucks, the mileage sucked! 5 to 5.5. the company, leasing company, and freightliner went round and round about the poor mileage.
older trucks got 6 to 7 mpg. freightliner tried to blame it on the drivers.
but it all came down to the emissions system on those new engines.
we shudder to think about the next new truck lease, with newer emissions standards.

[natewoz]

One of our technicians was telling me the fleet he used to work for had 300, 2006 model year and older trucks sitting in long term storage waiting to be cycled into the fleet as their trucks needed replacement. Knowing the guy, I'd trust him on that one.