Pure Diesel Economics

Maximizing Fuel Economy

Published in the October 2010 Issue October 2010 PowerStroke

F250 Super DutyIf you own a 2008-2010-era diesel truck, you probably know the frustrations of buying a $40,000-plus truck that gets worse fuel mileage than a 1985 Chevy Suburban.

When Mark Evans bought his 2008 Ford F250 Super Duty crew cab with the then-new 6.4L sequential-turbo diesel engine, he was less than impressed with the truck's fuel economy. Diesel fuel was going through the engine quicker than stimulus money was going through congress. The poor fuel economy made it tough to justify using a truck like this for anything other than towing. Evans talked with Pure Diesel Power about a solution to the fuel economy problem. Pure Diesel Power put together a package specifically suited for the 6.4L Power Stroke (although similar packages are available for GM and Dodge applications). The package consisted of an SCT Livewire 96250R flash device, an S&B cold air intake system, a Flo Pro stainless DPF and Cat-delete pipe kit and EGR blocker plates.

The SCT tuner flashes the ECM with pre-loaded tunes that offer increased horsepower. Most performance fuel maps have a tendency to increase a diesel truck's fuel economy by getting more energy out of each crank rotation (the key is how the driver controls the throttle, though).

The SCT Livewire's display shows a range of gauges, including exhaust gas temperature (EGT), boost, rpm and trans fluid temp. The monitor can also display estimated horsepower and torque, and shows quarter-mile ETs and 0-60 mph runs. The three preloaded tunes offer gains of 60-, 120- and 160-horsepowr and up to 300 lb-ft of torque at the rear wheels. You can also read and clear diagnostic trouble codes (DTCs) with the SCT Livewire.

The off-road version of the SCT tuner also lets the user delete the diesel particulate filter (DPF), diesel oxidation catalyst (DOC) and exhaust gas recirculation (EGR) systems without the engine throwing trouble lights.

One of the perks of running the SCT Livewire tuner is the ability to do custom transmission tuning. There's even an option to run a transmission tune with no added fuel-a great option for heavy towing on stock components.

The S&B cold air intake system is claimed to flow 23.4 percent better than the stock intake, with an efficiency rating of 99.48 percent at 593 CFM using ISO coarse dust. The filter element is cleanable and reusable.


Evans' truck is a 2008 F250 (Job 3) with a 2-inch front level kit, rear air bags and 35-inch tires on 20-inch wheels.

Evans drives the truck cautiously, with more attention paid to maximizing fuel economy than we usually see.

With the intake, exhaust and tuning completely stock, the truck would do a consistent 12.6 mpg, city driving with some rural commuting. And that includes three DPF regeneration cycles on average per tank full.

Freeway driving (75 mph) would get the numbers up to 13.3 mpg on average, with two DPF regeneration cycles per tank of fuel.

The truck, like any stock 6.4L, was quick once rolling, but sluggish right off the line.

With the SCT Livewire tuner (No. 3 120HP tune flashed), Flo Pro exhaust components, S&B cold air intake and EGR blocker plates installed, the truck's fuel economy improved to 14.2 mpg city (an improvement of 1.6 mpg or 13 percent).

Freeway mileage increased to 16.7 mpg (a gain of 3.4 mpg or 26 percent). That's tough to beat.

Evans says the SCT Livewire tuner adds much quicker throttle response and makes the truck fun to drive again. So much for plans of upgrading to that '85 Suburban.


Pure Diesel Power

Custom Auto

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