10-4 Magazine - For Today's Trucker

September 2006 - Performance Zone
FUEL ISSUES & MORE
By Performance Specialist Bruce C. Mallinson

Ultra Low Sulfur Diesel Fuel is now with us, and those of us who have older diesel engines may be in for serious problems. I have four Dodge Cummins pickups and one Kenworth and all of the engines are mechanical, with the newest being a 1996. Am I concerned? You bet I am, and if you have a 2002 or older engine, you should be too.

Lubrication (or lack thereof) is what I am concerned about the most. A barrel and plunger in an injector or a fuel pump only has 40 millionths clearance and needs the paraffin and sulfur in diesel fuel for lubrication. Now that its all been removed, what is going to lubricate the fuel system? As of this writing, nobody in the industry has been able to tell me, so I met with Forest Lucas and his head chemist Del Finley for some answers as to what I should do to my fuel so my older mechanical engines do not score the injectors and the barrel and plungers in the fuel pumps. Even if you have a 2002 and older electronic engine, you still have barrel and plungers in your fuel system and they need lubrication.

Forest, Del and I came to the conclusion that for the next several months, I should double-up on the amount of Lucas Fuel Conditioner I am putting into the fuel. Right now, one gallon of Lucas will treat 400 gallons of diesel fuel, but I agreed to start using one gallon of treatment per 200 gallons of fuel. I know it’s expensive, however, so is a new set of injectors. And if the fuel is the culprit, what will keep the new injectors and fuel pump from scoring?

Please don’t think this will not happen. Remember back in 1993 when they greatly reduced the amount of sulfur in the fuel and all the problems we had with the fuel pumps on mechanical engines? Well, it just may happen again, so please think about overtreating your fuel for the next few months until we see what happens with the new Ultra Low Sulfur Fuel. Also, check to see if the fuel conditioner you are currently using adds lubricity to the fuel. I know that Lucas does, however I’m not sure about the others. If yours doesn’t, I suggest switching to the Lucas Fuel Conditioner.

Summertime, when the weather is hot and humid, is a terrible time for diesel engines. High ambient air temperatures and high humidity displaces oxygen in the air and causes diesel engines to run less efficiently then they do in cooler, dryer climates. Driving at night or on cool, dry evenings is the optimum environment for your diesel engine to run its best. Have you ever noticed how the exhaust gas temperature drops once the sun disappears over the horizon? The older engines without charge air coolers were really affected by the sun’s rays. The effect is still there, you just don’t notice it anymore.

John Walko of Walko Racing manages, tunes and builds IMSA Road Racing cars. These cars have a computer onboard that, among other things, measures the G-forces on the car while cornering and accelerating. According to John, the forces are greater in the evening because the amount of horsepower produced by the engine is greater once the sun goes down. Something else happens during the late evening, right around sunset – the movement of air slows. I have noticed this while riding my motorcycle. At night or in the evening, I can hear the radio much better than during the daytime.

So, think about the weather. If your body is uncomfortable with the heat or the cold, so is your engine. If you’re not comfortable working outside because of the weather and you just don’t want to work, neither does you engine. Your engine will talk to you – listen to her. If she doesn’t want to pull the way you think she should, it may be due to the weather.

While snowmobiling in northern Quebec in 1996, the temperature dropped to 25 degrees below zero, but my 1995 Dodge Cummins pickup started just fine because she was plugged in and the engine was warm. However, I noticed while driving down the highway there was a trace of white smoke coming out of the exhaust. Because the air was so cold and the charge air coolers on today’s engines are so efficient, the engine was not able to burn all of the fuel, thus creating some white smoke. So when your truck is emitting white smoke from the stacks, be gentle with her and just ease on down the highway.

High altitude can also affect your engine’s performance. Vail Pass and the Eisenhower Tunnel on I-70 in Colorado are two places where your engine just won’t want to perform. Altitude displaces oxygen and your engine loses 3% of its power for every 1,000 feet of elevation. So when you’re at 10,000 feet, your engine is missing 30% of its power. The turbo compensates for much of the power loss, however the pyrometer will run hotter because of the lack of oxygen in the air.

Did you ever think about how your body and your engine are really alike? They both burn oxygen (you can only live about 45 seconds without oxygen and your engine will stall immediately without oxygen); they both take in fuel (you wouldn’t put junk fuel into your engine so don’t put junk food into your body); and they both have waste to get rid of (if your body doesn’t get rid of its waste for a few days you could have a problem, but your engine has to get rid of it every second). Your engine’s waste has to pass through a muffler. When you leave the stock muffler on your truck, the waste is being held back (constipated). Having a constipated engine costs you money – as much as 1/4 mpg or 1,000 gallons of fuel every 100,000 miles.

Some of you guys truly amaze me – you’ll drive a truck with a single stack and a constipated muffler knowing full well that it is seriously affecting your engine’s performance and efficiency. Some of you have even told me that you are going to wait until your stock muffler wears out before you replace it. You can’t afford to wait until it wears out – it’s costing you a ton of money. If you’re looking for better response and fuel mileage, then start with the muffler. Install one of our quiet, straight through mufflers and allow your engine to get rid of its waste. Every day that you wait, it costs you about $25 in fuel!

Free running horsepower makes for a great running truck, and the better your truck runs, the better care you will give her. And like I’ve said in the past, horsepower is a win-win situation! If you have any questions or concerns regarding diesel engine horsepower and/or efficiency, send me an e-mail at bruce@pittsburghpower.com or call me at Diesel Injection of Pittsburgh at (724) 274-4080.