FUEL EFFICIENCY Archives — Auto Trends Magazine

A third Duramax GM diesel becomes available.

GM’s latest Duramax diesel is this inline-six.

The General Motors Company makes diesel engines under the Duramax name. Most of us are familiar with the 6.6-liter turbo-diesel V8 available with heavy-duty Chevrolet and GMC models. We may even be familiar with the 2.8-liter turbo-diesel four-cylinder engine available in smaller trucks such as the Chevrolet Colorado and GMC Canyon.

But there is a third engine, this one a 3.0-liter turbo-diesel inline-six, which has received much press lately. This particular engine is available in light-duty Chevrolet Silverado 1500 and GMC Sierra 1500 models. Importantly, it is the first time in a generation we’ve seen a light-duty diesel engine for these models. Thus, we’ll explore certain salient points about the new engine, an option to consider when shopping these models.

7 Fast Facts

1. Delayed by one model year.

GM originally planned to release the new diesel engine late in the 2019 model year. It was the last engine on the docket for the rollout of the all-new 2019 models, but the EPA slowed things down. After a three-month delay, GM decided to release the engines for the 2020 model year. As of publication, the first models equipped with the new turbo-diesel are available.

2. A clean-sheet design.

The new Duramax diesel isn’t a derivative of any other engine on the market. It is a clean-sheet design, which utilizes a lightweight aluminum engine block and cylinder head. Ceramic glow plugs ensure a quicker start on frigid days, thus an engine block heater isn’t needed until temperatures reach -22 degrees F (-30 C).

3. Copious amounts of power.

Small in size, the inline-six is a powerhouse with an output of 277 horsepower and 460 pound-feet of torque. Ninety-five percent of its peak torque is reached at a very low 1,250 RM, with 100 percent sustained from 1,500 to 3,000 RPM. GM marries this engine to a 10-speed automatic transmission. Ford also utilizes a 10-speed, while Ram has an 8-speed. One further note: neither the competing Toyota Tundra, nor the Nissan Titan offers a diesel option (The Titan XD has a 5.0-liter Cummins turbo-diesel, but that engine is going away after 2019).

4. Robust payload and towing.

Choose the four-wheel-drive Chevy or GMC and you’ll find maximum payload of 1,870 pounds and a top towing capability of 9,300 pounds. The truck’s trailering capabilities will satisfy most needs, with the 6.2-liter gas V8 handling the rest.

5. Top-notch fuel efficiency.

Fuel economy hasn’t always been a big deal in a segment that emphasizes size, payload, and towing capabilities. Indeed, gas engines typically average 15 mpg, which pales in comparison to what cars are making these days. The new engine, however, changes that as equipped two-wheel-drive models earn an EPA-estimated 22 mpg in the city and 33 mpg on the highway for a combined 27 mpg. Choose the four-wheel-drive model and these numbers are 23/29/25 mpg city/highway/combined.

6. Best in class fuel economy.

GM claims bragging rights with the new diesel, beating its top competition, namely the Ram 1500 and Ford F-150. Both manufacturers have diesels with nearly identical displacements. The two-wheel-drive 2019 Ram makes an EPA-estimated 20/27/23 mpg city/highway/combined, while the four-wheel-drive version comes in at 19/27/22 mpg. As for the 2019 F-150, its best fuel rating is 22/30/25 for two-wheel drive, while the four-wheel-drive model earns 21/28/24 mpg. It’ll be interesting to track how these numbers hold up under real-world conditions.

7. No price penalty.

Shop for an efficient engine and you’ll pay through the nose for it, right? This seems only logical, but happily, it isn’t so. You’ll still pay extra to acquire this engine, but GM assures us that you won’t. Notably, the company says this about the cost: “It is priced identically to the 6.2L V-8 as a $2,495 premium over a 5.3L V-8 model or $3,890 over a 2.7L Turbo model.” We like that GM is holding the line on prices.

Looking Ahead

The new turbo-diesel engine should serve as a boon for Chevrolet and GMC. Much has been made about the Chevrolet Silverado ceding its second-place sales standing to the Ram 1500 this year, but we think the new engine will serve as an important marketing catalyst. Competitively priced and efficient, we may see a spike in diesel demand across the board. The only significant downside is availability, as not all service stations carry diesel. And for those that do, diesel costs .25 to .50 more per gallon than regular gasoline, yet still costs less than premium-grade gasoline.

See Also — Like a Rock: 2019 Chevrolet Silverado

Photo copyright the GM Company.

Disclaimer: Never put yourself or other drivers in harm’s way when practicing some of these techniques which may, incidentally, be illegal in some jurisdictions.

Hypermiling with three pedals at the ready.

There is a group of people on the roads who seek to squeeze more miles out of a gallon of fuel than seems scientifically possible. Known as hypermilers, these individuals examine the EPA fuel ratings for their vehicles, then find ways to beat those numbers by 5, 10 or 20 or more miles per gallon.

Hypermiling may seem like some off-beat way of driving, but it just may be something that you are already embracing in a bid to save fuel. Let’s take a look at hypermiling and what it means for those who participate in this fuel-saving strategy.

Hypermiling Defined

Simply put, hypermiling is a process where car owners make adjustments to their vehicles or to their driving techniques (usually both) in an effort to maximize a vehicle’s fuel efficiency.

Such drivers typically operate their cars at lower speeds and engage in coasting to maximize their mileage. You should know that not every method here is safe and Auto Trends isn’t endorsing the practice, but we are pointing out the strategies that some drivers employ to increase their gas mileage.

Enhance the Tires

Importantly, never do anything with your tires to potentially harm them. Tires should always have sufficient tread and be inflated to the car manufacturer’s recommended pounds per square inch (PSI) rating when cold. Some drivers opt for low-roll resistance tires, which can increase fuel economy, but may also affect handling.

What some hypermilers like to do is to attach wheel skirts to the rear wheels in a bid to better manage airflow, a method used to increase fuel efficiency. If you install skirts, ensure that they are securely fastened, otherwise, they may fall off and litter the highway.

Kill Your Comfort

Serious hypermilers also resist using the air conditioning as they know that the climate control system is a drain on fuel efficiency. It is a comfort-killing method that can be brutal to employ on a warm day.

But keeping the A/C off isn’t enough — all windows must be tightly shut, otherwise, wind drag will adversely affect fuel economy. As you might imagine, this step is only for the truly dedicated people who can withstand intense heat and the odoriferous results.

Cruise and Speed Control

One of the best ways for all drivers to save on fuel is to activate the cruise control at highway speeds. However, you do not want to activate the cruise control when roads are wet as you may inadvertently cause your vehicle to spin.

Hypermilers, though, may not rely on cruise control as they prefer to be in control of the car’s speed at all times. On the highway you can see them in the right lane, typically going well below the speed limit and hugging the white line on the right side of the far-right lane.

Where hills are involved, a hypermiler practitioner may build some momentum while climbing and then cut off the engine while moving down the hill, coasting his way along before restarting the engine. This step is possible only if the steering wheel doesn’t automatically lock when the engine is turned off. As long as you have control of the wheel and your foot is ready to apply the brake, you can pursue this option.

Go Light as in Real Light

If the previously mentioned tips are leaving you frowning, there are some other methods of achieving higher fuel mileage that may be more to your liking. Certainly, a number of hypermiler techniques seem extreme and some are not particularly safe.

For the rest of us, you can squeeze more miles out of a gallon of gasoline or diesel fuel by doing the following:

1. Empty your trunk. For every 100 pounds of stuff in your trunk or behind your back seat, your vehicle fuel economy will fall by about 1 percent. As you might imagine, smaller cars benefit more from removing junk than larger vehicles.

2. Remove your roof rack. If you carry anything on the roof of your car, wind drag will harm fuel economy, dropping it by as much as 25 percent according to the EPA. Hypermilers not only avoid this practice, but they are also likely to remove the roof racks. However, they don’t stop there — some drivers remove the back seat and anything else inside the vehicle that can save weight without compromising safety.

3. Idling is awful. Hypermilers live for green lights and will often time their driving to avoid stops of any kind. You can’t always avoid the lights, but if you are stopped at an intersection for more than a minute or are waiting for a freight train to pass, cut off your engine and you will save fuel.

4. Start slowing and avoid braking. You will kill your fuel mileage if you employ any number of aggressive driving techniques, including rapid acceleration, quick braking, and speeding. Hypermilers essentially crawl away from a stop and gradually build back to their intended speed. When it comes to braking, they often do so only when absolutely necessary, timing their driving to pass through synchronized green lights.

Hypermiler Considerations

Devout hypermilers also employ a number of other strategies to help them improve their fuel economy. On highways, some prefer to ride immediately behind an 18-wheeler, allowing the big rig to absorb wind drag. The problem here is that some ride too close to trucks, thus the rig driver is not able to see them in his mirrors. Where a safety issue exists, avoid that practice.

Smart ways to save on fuel involve taking roads that are less traveled, taking advantage of tailwinds and avoiding crosswinds as well as headwinds. Taking to the road when the weather is warm, where traffic is light and when road conditions are favorable are other ways to save fuel. And if you have a GPS system, use it to avoid traffic delays or what can seriously hamper your fuel economy.

Notes

Jalopnik: Hypermiling Is Awful And I Sort Of Hate It — http://jalopnik.com/hypermiling-is-awful-and-i-sort-of-hate-it-1647016853

Ecomodder: 109 hypermiling / ecodriving tips — http://ecomodder.com/forum/EM-hypermiling-driving-tips-ecodriving.php

FuelEconomy.gov: Driving More Efficiently — http://www.fueleconomy.gov/feg/driveHabits.jsp

Photo attribution: Public domain photo via Wikimedia.

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