I understand that 2007's (including GM ,Dodge, Ford, Freightliner,etc.) are to be running hotter. I understand that they will be assembeled with 20% larger radiators. If that be the case I can assume that fuel milage will be 20% less since more energy will be expended out as waste heat in order to get the same energy to the pistons to do the work that had formerly been done .

:(

You have a good point but I think your kinda confused. Putting a larger radiator in isnt going to reduce fuel milage, it is only going to cool the engine better.

Maybe the heat in the engine is required for that new exhaust device that is required in all 07 diesel vehicles.

What happens if the engine gains thermodynamic efficiency from increased combustion temperature?

What happens if the engine gains thermodynamic efficiency from increased combustion temperature?

:think: Please gear that down for a dumba$$ like me!

By thermodynamic I assmume you mean the relationship between the heat of the engine and other systems. If this is the case I still dont understand your question.

Thermodynamic efficiency is basicly how much heat is expelled from the motor vs how much is converted to work. Generally speaking, the lower the efficiency, the lower the fuel economy and power are. You have to include 3 areas of heat loss, including exhaust, cooling system, and convective + radiant heat off the motor as heat losses not converted to power. For total efficiency of the motor you also have to take into consideration fuel that isn't completely combusted to water and CO2

Ok I think I understand a little better. The engine and components are thermodynamic-ly balanced as is from the factory. They have adjusted the entire system to match the amount of heat expelled from the truck. With the engine making more heat they had to combat this with a 20% larger radiator.

Did I answer your question or am i still lost?

Todd

The point I was making was the fact that the new engines are going to be using more fuel (heat) to do the same work, requiring bigger radiators. (another governmental step backward).

IMHO, the older the engine, the better for fuel economy...all things being equal. Newer may not be BETTER i.e.2007 !!!

My next question is going to be what will the 2010 diesel engine look like and at what cost??? (the next diesel emission tightened requirement).

It looks to me that diesels, at least for light duty vehicles, will become a thing of the past....a financial loozer for those with those above 200k, eventually becoming 300 k miles and beyond. Maybe we will be able to buy a glider kit for a pickup and install your old diesel and save a few bucks in the meantime...

-:t

Oh no, I see diesels becoming the major if not the only source of transportation. That and hybrids coupled with diesels.

Look around in the us, whats the fastest growing market even over hybrids? answer diesels.

What does a majority of countrys use as a fuel for their vehicals? answer diesels.

Why does the army ect. only use diesel vehicals? Answer thats all they can get overseas in other countrys.

It may not be the same stuff we burn today, but it will most likely be a diesel that carries us into the future.

And the best advice now is buy a 2006 before the 2007's come out. If the 2007 are any good then trade up.

But thats just my 2 cents.

Todd

The one caveat to increased diesel demand will be the increased cost associated with all the new emissions equipment. I think folks will be shocked at how much more expensive the '07 trucks will be, and if that's the case, increased cost generally results in reduced demand.

The increased heat (at least a big part of it) is due to the incresed amount of EGR. The big EGR engines (DMAX incl) use cooled EGR, which is simply cooling the exhaust that goes back into the engine. This adds a fair bit of heat to the coolant that needs to be expelled (bigger rad). EGR rates are on the way up for 2007 to further lower NOx emissions. I wonder if the EGR cooler on the 07 DMAX is bigger than an 06?

I thought (but am not sure) that when an engine operates at a higher temperature it can more completely combust the fuel. I seem to recall some guys trying to build a ceramic engine a few years ago in order to allow the engine to operate at a higher temperature. However unless you get more useful work from the extra heat it is just that extra heat which must be removed.
Sorry if I confused the issue. I was thinking with my mouth open... I mean fingers moving.

That ceramic engine deal was neat, it's too bad nobody has made it work (on a large scale) yet. High heat means great combustion but it also means a ton of NOx emissions. Emission technology has actually been working against diesel efficiency since 1998 with the worst jump being the 2002 engines. So in exchange for "clean" air we get lower fuel economy and get to buy more high priced oil from people that don't like us.

This is progress?????