Hoovey689

iTrader: (16)

Ride along as CleanMPG teaches us how to hypermile a Ford F-150 EcoBoost

"Who Says A Huge Truck Can't Get 30+ MPG?"


The first time he suggested it, I hesitated. After all, I'd never tried to drive a vehicle at 45 miles per hour with the engine completely off. But here I was, cresting a long hill on a highway somewhere in Oklahoma and Wayne Gerdes was saying in a strong voice, "Do a FAS. Turn it off, turn it off. Shift to neutral, then turn it off." I followed his instructions, finally, and hoped that the nice people from CleanMPG who were in the truck with me were not going to get hurt when we crashed.

Of course, that didn't happen. A modern Ford F-150 will, when you turn the key to the accessory position after shutting down, operate mostly the way it does when the engine is on. (See Ford's official disclaimer below; these are not fuel-saving tricks that the untrained driver should attempt.) The power steering is active, the radio doesn't even stop playing and the brakes work (not that Gerdes would ever touch them). Once I got used to how the truck works, I was FAS-ing every chance I got. On one particularly amazing FAS (don't worry, acronym explanations are coming up), I hit 67 mph. It was a triumph.

Learning to FAS – one of Gerdes' many hypermiling tips – was one of the main reasons I was along on his latest high-mileage challenge. In the past, he has gotten 59 mpg out of a Hyundai Sonata and 81.5 mpg in a Ford Fusion Hybrid, so he's more than familiar with beating expectations. This time, the idea was to see if a fully loaded truck packed with five people and a bed full of gear could drive coast-to-coast (California to Georgia) while getting over 30 mpg. For the trip, Gerdes selected the 2011 F-150 XLT with Ford's EcoBoost 3.5 liter V6, which the EPA says gets 16 mpg in the city and 22 on the highway. What do they know? Heck, what did I know?

I joined the trip from Oklahoma City to Atlanta, a distance of around 870 miles the way we were going. Hopping in on the middle portion meant that I missed the mileage-crushing Rocky Mountains (with, granted, its wonderful downslopes) and some desert heat (hypermilers shun A/C use). Most drivers can tell you that gradual starts and stops can increase your mpg, as can driving below the highway speed limit. CleanMPG, though, is about really proving that the EPA's MPG numbers are much too low. By the time I got behind the wheel, the overall average mpg displayed on the stock Ford info screen was 34.1, a thoroughly impressive figure.


The CleanMPG folks, though, aren't exactly the type to sit back and trust anything an automaker tells or shows them. One way to understand these guys is to think of them in terms of computer geeks, but for cars. These aren't Prius fan boys (think: Mac users) and they're not gearheads trying to squeeze every ounce of performance out of a used Mustang (think: hardcore PC gamers). Instead, these are the Linux users of the car world. In an odd way, they may know their vehicles better than the engineers who created them. Take, for example, the tale of our truck's gas tank.

Officially rated with a 26-gallon capacity, Gerdes was surprised when he did his standard hypermiler fill-up and pumped in around 36 gallons. See, Gerdes knows that there's only one way to be sure how much fuel you've burned: accurate numbers. Thus, you need to fill up the tank until you can actually see the gasoline by filling up very, very slowly; like 30+ minutes slowly. Yes, this fills up the tank's vapor space, but this is how these guys roll.


Of course, if you fill the tank this much, you'll likely spill a bit of fuel. Automotive engineers prepare for situations like this and build in tiny holes right at the fill spout that drains through a stainless tube onto the ground. Gerdes said he puts a collection tub under this spout so that when he tries to save fuel, he doesn't instead pollute the ground. The important thing is to know that you're starting with a completely full tank (which can then be contrasted with how much fuel goes in on the last fill-up). The other component here is an accurate distance gauge. Before each headline-grabbing road trip, Gerdes and his crew make sure to compare the on-board odometer to 100-miles' worth of markers distance markers along the side of the road. With these two numbers in hand, Gerdes sets off, sometime pushing the truck to the best spot in the parking lot so that, once you've started the engine, you're instantly ready to move. It's as if wasting gasoline offends him – and why shouldn't it? There are free miles just laying everywhere, like in the slope of a parking lot, and most people just leave them sitting there.

Pushing a vehicle into position is just one more trick hypermilers can use to decrease the amount of fuel they need to burn to go anywhere. Hanging with hypermilers introduces you to a bewildering array of new terminology to describe these tricks: FAS (a Forced Auto-Stop, described above), NICE-on (Neutral, ICE on – like a FAS, but with the engine running), and Driving With Load, a key idea: you want to keep the engine at a constant, efficient rate while letting your speed vary (one journalist who participated in the Challenge before me, Jill Ciminillo of Chicago Now, has created a longer list for the uninitiated). One thing Gerdes does not recommend is drafting behind a truck, as that's a bit too dangerous.


Gerdes uses all these terms fluently, and his CleanMPG friends know what he's talking about when he does. They don't always agree with him on the forums, but on this trip, Gerdes was in charge, directing them from the F-150's passenger seat just as he directed me. I learned one lesson the time we came a railroad crossing at the bottom of a slight hill. We had been running parallel to a train for a mile or two, talking about how geeky some train fans can be (takes one to know one, right guys?) when we saw the flashing red lights down a ways indicating that the train was about to get in our way. "Shoot," Gerdes said, directing the driver at that moment to shift into M and then downshift into first gear. This made zero sense to me. We were going to have to stop anyway, right? So wouldn't this be one of the rare times when it's okay to step on the brakes? Of course not. There is never a good time to step on the brakes (well, almost never).

See, the trick – again – is to understand exactly how the vehicle you are driving works. In Ford's F-150 XLT with the 3.5 liter EcoBoost V6, that means knowing that the fuel cut comes at around 1,100 rpm. Oh, and it also means understanding what the fuel cut is.


Fuel cut is the point at which the engine will still use the vehicle's momentum to keep the engine turning over. Every internal combustion engine (except those with auto stop-start or an electric motor) wants to make sure that it continues to spin, otherwise it will stop running. (If you've ever driven a manual and stepped on the brakes without first stepping on the clutch, you know what we mean.) When the engine rpm drops below a certain point (in this case, 1,100 rpm), the car will send a bit of fuel through the injectors to keep everything humming along. This can be a complete waste if you're a hypermiler, because there is another way to keep the engine spinning: downshifting and fuel cut.

Thanks to the transmission, you can use the rotation of the wheels to spin the engine. If you downshift at a higher speed, the engine will spin faster (i.e., at higher rpm) as it slows down the vehicle – neatly preventing the computer from turning the injectors back on again while slowing down. This technique is called smart braking, and any time you're moving without burning fuel, it's called fuel cut.


Compare this to what happens when you step on the brake pedal during a normal stop in an automatic transmission-equipped vehicle: the torque converter unlocks and then all you have is the fluid coupling. This means that the drive wheels are spinning independently of the engine and the rpm number drops. Stepping on the brake pedal simply converts momentum to waste heat while still burning fuel. No one wants that.

As it turns out, the flashing red lights were for a stoplight, not a railroad crossing. But this turned into a teachable moment, one of hundreds for me along the journey. Gerdes knows that not everyone is willing to do stuff like this to cross the country in a heavy pickup truck using just over two tanks, saying, "That's us, that's not everybody."

So, how did we – the novice journalists and experienced CleanMPG members together – do? Overall, the 7,120-pound F-150 with people and gear managed 32.281 mpg over 2,468.7 miles. The Ford Fiesta chase car, similarly loaded and achieved, got 63.5 mpg. That pretty much confirms it: there are extra mpg laying around everywhere, you just need to know where to find them.


We asked Ford about some of these driving tricks, and this is the official, vetted response:

First, we have to make it very clear that Ford does not recommend or endorse turning off the engine and coasting as a method to improve fuel economy.

We can tell you how the F-150 will behave in the unlikely event the engine should stall.

(1) The F-150 retains full braking power for a limited number of applications of the brake pedal, enabling the driver to bring the vehicle to safe stop as normal.
(2) The electric power assisted steering system remains active but not at 100 percent assist.

There could be instances where braking and steering efforts are affected. For instance, coasting down a long mountain road with the engine off could reduce voltage in the battery and affect the EPAS [Electric Power Assist Steering]. Also, the vaccum that powers the brakes would be depleted after several applications of the pedal.

And finally: We recommend filling the tank as per the instructions in the owner's manual.

Again, we should make it clear that no one should attempt maneuvers like this without proper oversight, training and an understanding of the risks. Clear? Good.

Gallery:
http://green.autoblog.com/photos/for...mpg-0/#4130674

http://green.autoblog.com/2011/05/12...-a-ford-f-150/

FireCode

iTrader: (1)

Two questions...maybe they're dumb questions but I have to ask anyway...

1. When you put the truck/ car in nuetral and turn off the engine, don't you have to come to a complete stop to turn it back on and to engage the drive gear?
2. The whole fuel cut thing sounds stupid to me. IF you downshift, this makes your revs increase. Revs increasing uses more fuel than at a constant rpm, right? What's the benefit of increasing revs over just coasting to a stop?

sc-driver

iTrader: (7)

1. If you ever turn your car off in neutral, you can turn it on in neutral too. I've tried this. So I don't see the difference between moving or non-moving as long as it's in neutral.

2. ALL modern cars cut fuel to the engine above a certain rpm (assuming the throttle is at 0%). My 96 sc400 cuts fuel above ~1100 rpm. The momentum of the car keeps the engine from stalling.

Hope that helps!

Putting like 5 more psi will help, driving in warm weather, lowering the car will help significantly, have an under engine cover helps, having the smallest diameter rims with the skinniest tires helps too, and obviously having your car as light as possible.

FireCode

iTrader: (1)

I Know you can start the car back when it is in neutral. My concern though is gettig it back in to drive if you are still moving. I would assum the tranny would not like that. Wouldn't you have to be at a stop to engage drive again?

sc-driver

iTrader: (7)

Oh I see what you're saying, it's probably not good if you do it A LOT at highway speeds but around the city you should be fine. If you're really experienced, you can rev match it first to reduce shock.

On most cars you can easily "pop" it into neutral and "pop" it back to drive without having to push like a shift change button or stepping on the brakes.

IS-SV

Wonderful, but it's easier to just get a new Prius and drive correctly.

Hoovey689

iTrader: (16)

Prius can't handle the towing and payload hah

IS-SV

Driving the way he's driving, I don't see any towing or hauling going on, so the Prius would be the better choice for the type of driving shown in article.

Hoovey689

iTrader: (16)

Maybe the Fiesta did better than both lol

IS-SV

The Fiesta wins!