Why do diesels cost so much to run?

Traditionally, diesels had the reputation for being durable, with great fuel economy, but when repairs are needed, expensive to repair.

In the new world of EPA compliant diesels starting around 2003, diesels have given up a lot of their historical reliability,  and in the first generation of diesel fuel fired regeneration Diesel Particulate Filters, considerably higher fuel consumption.

But wait.... something else happened.

On the way from the 7.3 to the 6.0, 6.4, and now the 6.7, we have seen horsepower and torque rise sharply.

During the last year of the 7.3, it produced 250hp and 525ft-lbs of torque.

Lets compare that to the 6.0 that replaced it, which produced 325hp and 570ft-lbs of torque.

Or the 6.4, rated at, 350hp, 650ft-lbs.

Now, the 6.7 is pushing 400hp, 800ft-lbs of torque.


Everyone complained of the poor fuel economy of the 6.4.

No one is asking the question, are we making fair compares when the engines are so different?

What about behavioral issues?  With that much more power, are users using the power or just using a very light foot as power increased?   It is a given that if you ask an engine to produce that kind of power it is rated at, it is going to have to burn fuel to make it.

Does that  suggest that much of the loss in fuel economy is due to different driving behavior?   Highly probable.

What about the loss in fuel economy from emissions devices like the EGR recirculation and Diesel Particulate Filter?

EGR, by lowering combustion temperature, certainly do have an impact on thermodynamic efficiency --- the larger the thermal gradient, the better the efficiency is a fundamental law of thermodynamics.

How about the DPF?  Yes, it does add a bit of exhaust restriction / back pressure.   But the real issue is fuel consumption during regeneration, as the current generation of mass market DPFs all use fuel for regeneration.   

In a future post, I will look at how much fuel does the DPF really use.

Ford 6.0 FICM Reliability Mod for F series Trucks.

Problem: FICM failures are a routine problem with F series 6.0s.

FICM Failures are far less common in E Series, and in the latest models (2008-2010) 6.0, FICM failures are a non issue!

So what gives?

FICM on the E Van is located behind the Degas bottle on the body, with a much longer wiring harness.

On the F, it is mounted right on top of the engine, where it is exposed to heat, vibration, dirt, and grime from the engine.


Solution: FICM Relocation.

Start with a brand new FICM, E Series FICM harness, and move the FICM physically away from the engine.

Manufacture a custom bracket that bolts to the fender / body.

Install heat shields / introduce cooling air.

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How:

You can see how much length you have to play with moving the FICM around with existing cable.

Then go to the E van, and look at their FICM location (behind coolant bottle) and their cabling.

Then ask... if you bought E van cable, where can you put it?

How much cable slack can you do without building your own harnesses? (Which is both cost and risk.)

Then, ask yourself, where in the engine compartment can you go that will get,

a) a minimum of heat

b) no vibration from engine

c) no chance of stress on cables etc.

And custom mod a bracket to do that.

Note: E van is high up and far to left corner behind coolant bottle.... not a bad spot.. huh?

Equivalent in F would be somewhere around the fender.

Be sure you secure the cables so vibration, heat, etc do not damage them. Use a J loop so cables shed moisture droplets downwards and to the rear of the engine compartment.

Then add heat shields to protect from radiated heat (from engine).

Air --- I would introduce air from the front apart from the rad in an insulated large diameter hose.

Be sure you engineer the hose to trap moisture (water droplets) and dump it before it gets to FICM.


Undecided as to whether I go completely passive (ram air) or (push with a small 12V fan).

Would have to gather some data with temp probe mounted on FICM in new location to see what is warranted.

Diesel Blog

Announcing the Gearloose Diesel Blog

Dedicated to operating modern on-road diesels that comply with applicable emission regulations at moderate cost reliably.

I started this blog because it was evident that there is a need in the blog space for hard nosed, reliable, technical and business information about how to operate light duty truck diesel engines economically and reliably.

Many sites are dedicated to performance, yet very few are concerned with,

a) compliance with applicable EPA rules

b) operating for long term, moderate to low costs.

In the age of $4 a gallon diesel fuel, and stringent emissions regulations, the North American market may have reached the turning point where the only way forward is to take a hard look at the kind of things that drove our previous fascination with diesels, namely, more and more horsepower and torque, and ask if that is really the way to go.

The vice of increasing cost of compliance with EPA regulations, and stricter and stricter regulations and inspections is at present a reality in many jurisdictions for Heavy Duty, and often, medium duty diesels.

It is but a matter of time before the rules and regulations migrate down to light duty diesels.  Owners will be faced with annual inspections, checks for emissions tampering, and stringent operating rules.

In the past, there was an escape --- namely, the "off road" market, where equipment was sold with the nudge, nudge wink that it is not for "on road" use.

However, that escape is gradually being closed as EPAs are gradually moving to regulate "off road" equipment, and ultimately, require that they be retrofitted with emissions gear as their "on road" cousins.

Rather than to fight this trend, perhaps, the diesel community has to ask, why not "go with the flow" and make this community as compliant as every other community of motor vehicle enthusiasts?

There are plenty of scope for EPA compliant mods and upgrades to deliver a fun experience for diesel enthusiasts.

Just as EPA rules did not kill off modding and tuning for gassers, there is no reason for us to think it will do the same for diesels.

That having said, lets at the outset say that my own goals are not necessarily for more horsepower and torque, but for long term durability and reliability.

I am basically after what the pre-2003 diesel market delivered --- rather than current products who have joined the horsepower and torque race.

Others will have different goals, and their tradeoffs will be quite different from mine.

That said, I will begin with a series of posts, starting with the Ford 6.0, and then on the 6.7 as examples of excellence in modern diesels.

I can see many will be upset with me for including the 6.0 in this "classic" list, but I am firmly of the opinion that properly maintained and cared for, the Ford 6.0 is one of the least appreciated, understood, and most maligned product of the last decade in auto engines --- gas or diesel.

Welcome

This is the new home for technical notes for Gearloose, who posts under Gearloose1 on different forums about Ford Trucks.