OT: semi mileage

I have a question about how two different drivers can get
different mileage on the same load. I run team now in a
2014 T680 automatic. We did a load this week to
Washington state and on the way back, loaded to 78000, in
730 miles I averaged 7.0 a gallon. Just woke up and the Co
driver only averaged 6.4 on 690 miles. He wont use the
cruise and always has the Jake on. I always use the cruise
and only use the Jake in mountains, plus I am a little
quicker on throttle. What is it that makes this much
difference. If I can figure it out will adjust what he is doing
but not sure at this point.

lot of variables in that, in 600 miles the terrain could be a big factor,..but like everything just the way you drive could be the only difference, my brother was one that would always be on the throttle then off then on again, it made a lot od difference in mileage,...friends and I used to shoot a lot and I could never understand why when one would sight in a weapon we could all shoot the same size group but they were never in the same place on the target

If you're using something like a box trailer that catches wind the wind speed & direction could factor in.

My uneducated opinion, it"s the cruise. A steady constant throttle will beat goose-it-slow-goose-it-sslow every time.

I am no professional driver. But I notice a similar difference when A buddy of mine drives my truck. What I notice is every start up he makes is flat to the floor. And every stop is last minute with the jake. When I drive I tend to speed up slower and coast to a stop more. I know I use less brake then he does with the Jake. Had a wife that drove the same way in with her SUV. We would get 2 mpg difference or more. I also notice they both do a little more tailgating and have to respond to every glitch on the road last minute.

We were running on similar roads from Casper WY down to 80 and east to De Moines, pulling a 53' reefer.

Could simply be driving style IE cruise VS foot driving. My SIL drives OTR. When he's home if we both drive his 02 Ford PS pickup I get about 2 MPG better than her does. He hates cruise, floors it and is always about 5 MPH over the speed limit. I never floor it and drive the speed limit. Now the company he drives for is happy with his mileage, go figure.

As far as shooting goes for the other poster. That because the different shooters are not getting the same sight to eye alignment. My youngest son and I get the same results off of any gun we shoot except pistol. The same SIL as above shoots about 2" left and 3" up off of the same gun.

Rick

on the newer rigs using the cruise will make a difference, as will individueal driver habits such as shift points onthe rpm scale, keeping the engine in its sweet spot will make it work less and get better fuel milage not letting the truck lug on upgrades, by not dropping a gear, even though the truck may make the grade in the gear its in, lugging will make a difference in fuel economy, if the engine is pulling hard down at the bottom of its power band it will burn more fuel, add in wind resistance and terraine and its easy for 2 drivers milage to differ in the same truck

Cruise usually saves fuel, so does engine brake. That much difference could be as simple as a bit more wind tho. Wind affects my truck more than weight.

(quoted from post at 06:20:15 04/04/14) We were running on similar roads from Casper WY down to 80 and east to De Moines, pulling a 53' reefer.

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I drive back and forth from Wichita KS to western KS and get different mileage each way because it is uphill westbound and downhill eastbound. Casper and Des Moines are about 4500 feet different - it is downhill TO Des Moines and uphill FROM Des Moines.

When I had my dump truck with C-15 Cat at 475 HP, it didn't have the computer that calculated it, but I kept track manually. I averaged 6.5 which I thought was good considering that half the time I was loaded heavier than most tractor trailers. I used terrain as the drivers manual advised. Slowly back off going up hills, then regain going down the other side. As others have said they did, I tried to anticipate stops and used brakes less. I was very surprised when driving bob-tail half way across the country twice for a friend that I did not get way better mileage. Probably the sky high sleeper affected it a lot.

I-80 across Ia. is fuel sucker. It doesn't look it but it's one hard pullin hill after another. Always just enough to max out the engine.

too many factors to actually calculate. cruise helps but other factors can't be duplicated!

Your long gun is recoiling into unique and different bone and muscle mass structures on each shooter. If each shooter is using good fundamentals, each shooter's groups should be similar but often in different impact areas from the other shooters.

Same between Lincoln, NE and Denver, CO. In any vehicle, it's about 2mpg better going east from Denver to Lincoln, than going west from Lincoln to Denver.

Denver is about 4,000 feet higher above sea level, but it's such a gradual difference you don't notice it.

While i was on the road not vary often was i at 78000 lbs maybe setting on the deck with 43600 under that with a 3406 550 Cat turned up to well over 700 ponys and during warm weather months i would see 6.5-6.7 every day in winter it would drop down to 6.2-6.4 . As for the cruise did not use it much and as for the Jake it was turned on when the truck got started and never shut off till the truck was . Years back before the onset of electronics . I ran a 855 Cummins that was turned way up and it also had stump pulling gears not road gears as 85 maybe 86 was tops for speed and i was pulling a coal bucket . the bucket was usually filled to the brim and at times looked like ya stopped a Dairy Queen . The only exception was Mangenies ore there ya did not want to look like a DQ stop or broke carbon electrodes Nah , half a wagon load was way more then enough and sometimes way tomuch . Usual load was around 120 to 140000 lbs and the old 4300 would pull down a good 5.5 to 5.7 . Carried 220 gallon of fuel on it and always figured 1100 miles between fuel stops. But back in them days only Refers did the LONG haul from coast to coast and us Coal buckets worked no feather out then maybe 150-175 miles from home running roads that make you youngen cringe . and as for a AUTOMATIC transmission Ah yea wright it was either a five and three a five and four or a 4x4 TWIN stick sticking up out of the floor , when the 13 speed came out we all thought that we died and went to heaven . The old ten speeds would not cut it and the fifteen speed only gave ya extra on the bottom . Back in 79 one company tried the Allsion in there new West Coast Macks with 400 Cummins , yea that worked out well for them lasted about five months and were removed and replaced with 13 speeds. Now today it is hard to find anybody that knows what that extra pedal on the left is for let lone be able to figure out what gear to put it in . And if they do master it they can only count to 10 .

Hello,
You answered your own question! Cruise control use is the big difference. Older computer controlled engines had more H.P. in cruise mode. So less shifting and better fuel mileage. I guess new engines are still set-up that way. Jake is also a fuel mileage minus! Like I said..... you answered your own question with your post,

Guido.

(quoted from post at 05:20:38 04/04/14)

(quoted from post at 06:20:15 04/04/14) We were running on similar roads from Casper WY down to 80 and east to De Moines, pulling a 53' reefer.

Click to expand...

I drive back and forth from Wichita KS to western KS and get different mileage each way because it is uphill westbound and downhill eastbound. Casper and Des Moines are about 4500 feet different - it is downhill TO Des Moines and uphill FROM Des Moines.

Click to expand...

Its downhill out of Wyoming to OMAHA........then the hills begin. They may not be as long as some grades in the mountains.....but there are some pretty steep hills in western Iowa. Ive run that route numerous times in both rigs and my pickup with a gooseneck. its smooth sailing til omaha

Terrain, weather, and habits all make a difference. A tank of cheap fuel could.
Guy I drove for back east ordered some mid-roof 9400 IH's, put drivers in them, and didn't see any fuel mileage differences between roof fairings and no roof fairings, so he went to buying without them. Never tried switching drivers between trucks and seeing if the driver's fuel mileage was any different with/without the fairing.
Running from Erie, PA to Charlotte, NC, with a mid-roof 9400, I could see a 1/2 MPG (and 1/2 hour time difference) between a dry box and a Carrier reefer. The Thermo-King's were good for another .2 to .3MPG.