Flatbed MPG

Ummm, your truck should not be leaking antifreeze to begine with. If it is, fix it and the problem is solved. I have no issues with putting $50 gallon anything in my truck (except for fuel) because I know it's not going anywhere but where it needs to be.

On that note, I run 100% antifreeze (no water) in my cooling system along with a gallon of Permacool just to keep the waterpump lubed for longer life and keep the gunk from building up in the hoses. My truck has stainless hoses now instead of the rusty old hoses that it came from the factory with. When I changed them out, you would not believe the gray/black sludge that came out of them. It took me 2 days to completely flush the system and I don't want to deal with that again.

The water worries me more due to the freezing point, than the boiling point. I don't need a pocket of water to sit in a crevise of my cyl head and the temps get down to -40 outside.....

 

I think you need to read your antifreeze jugs. 100% antifreeze will freeze around 20degrees without water. Unless your running a premix which is approx. 50/50 mix.
I'm not sure about the boiling point, but I do know antifreeze needs water to be active. It does not work in a pure state.

 

Flightline is correct, pure antifreeze freezes well above the freeze point of a water/antifreeze mixture. Also the boiling point of the mixture is higher. There is usually a chart on the jug that shows the freeze/boiling point of different ratios. Another advantage of the $50/gl stuff that most of us agree is better, but none of us will spend the money on. Maybe if I had a new truck I'd switch over, or if I did a rebuild on this one.

Vehicles on race tracks generally are not allowed to run antifreeze, at least not the common glycol based type the typical car, truck, or motorcycle uses. In a crash it can get all over the track and it takes massive amounts of water to clean up the slick spot. And those engines run about as hard as possible, localized heating is maximized and they are stressed to the max. When my bike is on the track the antifreeze is flushed and I run "Water Wetter". I have to check and see if it is compatible with antifreeze, if so it would be worth adding. It has a lower surface tension and better heat transfer, so it maintains better contact with the metal surfaces (think little tiny bubbles) resulting in more even cooling, less localized hot spots.

 

[TABLE="class: wikitable"]
[TR]
[TH]Weight Percent EG (%)[/TH]
[TH]Freezing Point (°F)[/TH]
[TH]Freezing Point (°C)[/TH]
[/TR]
[TR]
[TD]0[/TD]
[TD]32[/TD]
[TD]0[/TD]
[/TR]
[TR]
[TD]10[/TD]
[TD]25[/TD]
[TD]-4[/TD]
[/TR]
[TR]
[TD]20[/TD]
[TD]20[/TD]
[TD]-7[/TD]
[/TR]
[TR]
[TD]30[/TD]
[TD]5[/TD]
[TD]-15[/TD]
[/TR]
[TR]
[TD]40[/TD]
[TD]-10[/TD]
[TD]-23[/TD]
[/TR]
[TR]
[TD]50[/TD]
[TD]-30[/TD]
[TD]-34[/TD]
[/TR]
[TR]
[TD]60[/TD]
[TD]-55[/TD]
[TD]-48[/TD]
[/TR]
[TR]
[TD]70[/TD]
[TD]-60[/TD]
[TD]-51[/TD]
[/TR]
[TR]
[TD]80[/TD]
[TD]-50[/TD]
[TD]-45[/TD]
[/TR]
[TR]
[TD]90[/TD]
[TD]-20[/TD]
[TD]-29[/TD]
[/TR]
[TR]
[TD]100[/TD]
[TD]10[/TD]
[TD]-12[/TD]
[/TR]
[/TABLE]


[TABLE="class: wikitable"]
[TR]
[TH]Weight Percent EG (%)[/TH]
[TH]Boiling Point (°F)[/TH]
[TH]Boiling Point (°C)[/TH]
[/TR]
[TR]
[TD]0[/TD]
[TD]212[/TD]
[TD]100[/TD]
[/TR]
[TR]
[TD]10[/TD]
[TD]215[/TD]
[TD]102[/TD]
[/TR]
[TR]
[TD]20[/TD]
[TD]215[/TD]
[TD]102[/TD]
[/TR]
[TR]
[TD]30[/TD]
[TD]220[/TD]
[TD]104[/TD]
[/TR]
[TR]
[TD]40[/TD]
[TD]220[/TD]
[TD]104[/TD]
[/TR]
[TR]
[TD]50[/TD]
[TD]225[/TD]
[TD]107[/TD]
[/TR]
[TR]
[TD]60[/TD]
[TD]230[/TD]
[TD]110[/TD]
[/TR]
[TR]
[TD]70[/TD]
[TD]240[/TD]
[TD]116[/TD]
[/TR]
[TR]
[TD]80[/TD]
[TD]255[/TD]
[TD]124[/TD]
[/TR]
[TR]
[TD]90[/TD]
[TD]285[/TD]
[TD]140[/TD]
[/TR]
[TR]
[TD]100[/TD]
[TD]387[/TD]
[TD]197[/TD]
[/TR]
[/TABLE]

Running pure antifreeze seriously risks freeze damage to your engine since it freezes at 9°F. On the hot side though it is good to 387°F. It also does not absorb heat as well as a water/glycol mixture so a larger radiator or increased flow rate of coolant is required to maintain the same level of cooling capacity. Remember they system is designed around the coolant being between 40/60 and 60/40 mixture.

 

Running a nitrite free coolant takes care of buildup. They've found with the OAT technology nitrites actually aren't needed, and in fact are banned in some countries.

https://cglapps.chevron.com/msdspds/PDSDetailPage.aspx?docDataId=316362&docFormat=PDF

Also not having nitrites actually allows the coolant to cool better. The problem with Evans is it actually doesn't cool all that well.

If I had a fleet, every single truck would run the above coolant.

 

Some Evans added to the coolant helps surface tension which aids cooling. On the track we use it because glycol or any other slick substance is not allowed for safety, some people just run 100% water. Still have to run oil though, which is one reason oil drain and fill plugs have to be safety wired. The Delo A/F looks like a good formulation although it is still water/glycol mixture.

 

That is what I meant by 100% antifreeze. I run the pre-mix stuff and do not add any water to it. I see most guys run the distiller water and antifreeze at a 50/50 ratio, I just use the stuff out of the jug, I don't add water myself.

 

Back to the fuel mileage debate. I run a 10 kw t660 midroof without the wind jammer thingy pulling a 48' step I average every tank out on paper an every so often add it all up for an overall average an come out to 6.1mpg c15 Cat 3.36 rear 13sp trans. Best I did was 7.8 for the week but that was a light load of pipe going from pa to ga an then a low 40k load of steel back to baltimore. Worst was 5.2 thanks to a 2" crack in my intercooler

 

I am getting 6.29 for my yearly average running a 99 pete 379exhd flat top with a 475 hp cat 3406e. 390 rears w/10 speed overdrive and 24 tall rubber. I normally run 65-68 mph and close to 78000 most of the time. temp stay around 160 to 180. Approx 60% is oversize and 10% dead head. I use fuelgauges at mygauges to track the millage.

 

Something I don't recall seeing mentioned is tires. 22.5LP has a slight edge in mpg over the other sizes. Also newer LRR (Low Rolling Resistance) tires really do make a difference. Look at those ratings when getting tires, it all adds up in the end. Then there is the matter of tire pressure. I know people who absolutely refuse to put a tire gauge on a tire, using hammers and "thumpers" as their only tire check. Wouldn't be surprised if half the drivers here fall into that category. By the time you can tell a tire is low on air by that method it is would usually be declare "run flat" by DOT.

The people that chase getting as high a mpg as they can typically run 10-15psi over the normal pressure for tires. I keep all tires at 120psi. Some people are running 130. All my duals have crossfire tire equalizers on them to ensure both tires are always at the exact same pressure and that has made a huge difference in tire life and tire wear. There is no other way to get two adjacent tires to have the same pressure, and it does make a difference. Also you have a visual indication of the air pressure so every time you walk around your truck you can see if you need to add a bit of air, and I still stick a gauge on every week or two as a double check. Finally, when gauging or adding air, you only have one valve stem to deal with per tire position and it's out in the open, so it is so much easier to do.

One driver I know ####### about retreads, and had them on a trailer he bought. He blew out two tires on one of his first trips and blamed it completely on them being retreads. At the truck stop they checked all his tires and not one of them, tractor or trailer, had over 85psi in them and that's after going down the interstate. Figure 75psi cold. That's a danger to everyone. His answer? ... "I don't make money wasting time to check tires and put air in them, gotta get down the road". A few months later he got a DOT level one and had to replace eight trailer tires before rolling out of the scales from being out of service. Reason of course, air pressure below 80psi, and can't run on a tire that was run flat. Yeah, got to love those "old school" truckers.