okay i ve been thinking my truck runs better and more fuel efficient when it has warm air already noticing a difference in temps between 40-60 degrees, i know we have a grid heater,but i was thinking what if you had another or something like that you could wire to a switch to run when wanted and place on top of air filter in filter box to try to heat air even more to higher temps?

my thinking the warmer the air the more combustible the fuel will be like in summer

for instance now its getting colder i have to take off my ****** whistler cause my fuel mileage goes down hill when cooler and colder temps come into play.

 

I think the fuel mileage gained would be not worth the trouble. There are a lot more factors in cold weather like 13 quarts of cold oil in the oilpan to name one.

 

Lower oil and water temps hurt power. Cold air helps make more power by getting more air into the cylinder.

 

Cold air is denser air and like above, you get more into the cylinders which produce more power. If you could get the oil and water warm faster you will not see such adrop in mileage.. Not to mention we tend to idle longer in the cold months.

 

I use my Jake brake to help warm up. It will only help you some but it does help.

 

heating that oil will help i agree but when your on a road trip for awhile i think that would be up to temp, the temps are around 55-60 right now and went on a 2 hour road trip only seen 1 mpg different than town, i was just pondering it thinking about the grid heater, it kicks on to make truck start easier with warm air "more combustible" not more cold air, more power, is all. but just one of those ideas trying to save fuel and money
thanks for the opinions guys

 

Remember that we don't run spark plugs so when the steel in the cylinders is cold, at cold start, the added temp rise caused by the grid heaters is only needed for a short bit to help the mixture ignite more easily. Once the engine starts, the internal temps rise and the grid heaters slack off and quit. Just to clarify one point, the reason cold/dense air makes more is because it contains more oxygen. We really don't get more air into the engine, we get more out of what we put in.

 

By the time the air gets from the air box to the engine it has run through the turbo. It's compressed (read heat) and sent through the air to air (read cooler) and then on to the cylinder to be burned with the diesel. I doubt the engine will notice any increase in air temp. from the air box. You would have to have a red hot heater element just to keep up with the amount of air a diesel engine uses. The grid heater just gives the engine a shot in the arm, so to speak, on the initial start. Cold air/fuel mixture does not like to ignite very well, so the first ignition is given a helping hand. After that, the engine itself sustains the process.

Poor cold engine performance has more to do with cold oil, engine block, coolant, and a host of other cold things that work more efficiently when warmed up.

You might try an oil warmer if you wanted better cold engine performance, but I've never had much luck with them in semi truck engines. They tend to cook the oil immediately around the probe causing a crusty buildup which in turn diminishes the amount of heat that it will put out.

 

Actually we do get more air in when colder, as the only way to get more O2 is to increase air density. Air at all times and under all driving conditions and at any pressure has 20.9% O2 by volume. To increase the mole weight of O2for a given volume you have to compress it or cool it.

Air Density= Pressure/(specific gas constant * Temperature K)

Using that formula you can see air density increases as temps drop and thus you have more O2 molecules per volume.

As for the OP, it is not the cold air that is hurting your mileage, as mentioned it is the oils and other friction components that do not like the cold. The engine combustion process loves the cooler air.

 

There are a lot of other ways to save fuel. If you really want to pursue the hot air in winter thing just bypass the intercooler. That should yield a very warm intake air charge. Easiest thing is air up the tires, put a synthetic 5w-30 diesel oil like mobil one, and keep the right foot to a minimum.....

 

sweet guys that gives me and others some good answers, i love this site, alot of help thanks