How To Feed and Care For Your Diesel

I’ve got an in-depth thought about “micro-business” management cooking in my head. I haven’t made decisions on some of the details as to whether they should be shared, so I’ll save it for now, and pass along some tips on light truck diesel engines.

America seems to have a love/hate relationship with diesel engines. Lots of people love them, and lots of people hate them. It has essentially become a political issue, and while I think the “politicalness” of this subject is vane, I do think diesel engines are workhorses with a value that can’t be ignored.

With the 2007 advent of Diesel Particulate Filters (DPI’s) and Exhaust Gas Recirculation (EGR) valves, a whole new set of problems has come along, because the new diesel engines have essentially the same kind of problems that emission-controlled gasoline engines had in the 70’s and 80’s: They just don’t run the way they should, unless you drive them as intended.

Sure, diesel costs more in the winter and less and the summer (because No 2 diesel is different from No 1 diesel, and it’s competing with fuel oil for transportation space in the winter), but really we’re talking about overall efficiency, and the ability to power a workhorse. That workhorse is your truck.

I’ve had quite a few people ask me about my 2007 Cummins, and how it holds up. My answer is that it’s an awesome engine, pretty much on par with older Cummins engines, but the whole DPF and EGR setup leaves quite a bit to be desired. In other words, if I don’t drive it right then I will literally pay the price. I’ve heard several horror stories about diesel engines (Power Stroke, DuraMax, and Cummins) that plug up DPFs like they’re going out of style, or have EGR coolers go bad, and the whole Diesel Exhaust Fluid thing doesn’t help matters any. Quite honestly I’ve had none of those problems in 145,000 miles, but I pay a lot of attention to my Cummins. I don’t just jump in and drive it. We have a conversation during the entire trip, and I make sure to listen.

Here’s what you need: You need an aftermarket gauge/tuner setup like the system Bully Dog makes. You need to be able to tap into certain indicators like exhaust temperature, fuel use, fuel rail pressure, and so on. You need a system that will let you initiate a “DPF Burnoff” any time you want. You also need the “on the fly” tuning feature so you can make more power and increase fuel efficiency (at the same time) when you need it, and cut back a little when pulling heavy loads.

Then, you have to drive it like a diesel should be driven. You have to “blow the cobwebs out of it” every day. Don’t act like you’re taking Grandma to church, because you’ll plug it up. Suddenly you’ll get engine diagnostic codes saying your DPF is plugged up, your turbo is bad, and so on. When that happens, the first thing you need to understand is that you can usually resurrect it, just by going for a drive. Go into your aftermarket tuner and intiate a DPF Burnoff, then go for a long drive at highway speed. It’ll use some extra fuel, but an hour later it’ll run like new again.

I know a guy that runs a towing company and bought all new diesel trucks in 2009. He says he’s getting rid of the diesels because he just can’t afford them. The problem with the towing environment is the trucks sit idling a lot, and really don’t get driven hard until it’s time to perform. By then everything is plugged up and then there are problems.

OK, next tip: If you have an automatic transmission and you’re towing or hauling a load, make sure to use “tow mode.” If it’s a six speed transmission and you have a really heavy load, shut the overdrive completely off. Running in sixth gear with a load will generate too much particulate, because you’re essentially “lugging” the engine, and diesel engines naturally generate more particulate under power at low RPMs. If you have a manual transmission, make sure you keep your RPM in the mid-high range (2200-2500 rpm) so you’re making more power and generating less particulate.

The big one: Run your exhaust brake all of the time! Don’t shut it off. Every time you let off the accelerator that exhaust brake will clean a little particulate out of the DPF. Not only that, it’ll add quite a bit of life to your brakes and make your truck easier to drive in heavy traffic. If you want to capture more braking action from that exhaust brake, flip the transmission into tow mode as you’re coming off the freeway. It’ll slow you right down and clean that DPF really good.

Your driving habits will determine how much benefit you get from your diesel engine. My 11,000 lb truck with dual tires gets 23 mpg on the open highway, and 18 mpg pulling my 6,000 lb camper. It loves the workout, and you can feel it getting worked up when you hook a trailer to it. Suddenly you’re asking it to do what it was made for, like a quarter horse at the rodeo. Develop a relationship with your diesel truck like you would with a good horse, and it’ll give you many years of great service.