2009 BMW M3, 2009 Infiniti M45x, 2009 GMC Yukon - Gas Guzzler to Fuel Sipper Smackdown

May 14, 2009
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0906 10 Z+your Mileage May Vary+illustration
Driving usually isn't much of a challenge, but sometimes we make it one: Attempting to beat our best time for a trip. Trying to perfectly execute a heel-and-toe downshift. Plotting to nab the best possible parking space. Such activities add interest to the routine. What about the challenge of coaxing the most miles out of every gallon of gasoline? For us, that was a new one.
A contest of economy looked to be every bit as much a measure of skill, cunning, and iron will as is a contest of speed. This type of competitive driving is newly relevant and increasingly popular. Naturally, there are Web sites devoted to it. You've probably heard the word that describes it - hypermiling, for which CleanMPG.com's Wayne Gerdes takes credit. The term is relatively new, but the techniques behind it are not. In fact, the idea of a fuel-economy contest stretches back at least to the 1930s, with the widely publicized Mobilgas Economy Runs.
We decided to construct an economy run of our own, a test of man and machine. Ah, but which machines? To take the concept out of the realm of Toyota Prius owners and biodiesel Volkswagen Golf drivers, we wanted gas guzzlers. An SUV for sure, a sports car, a luxury sedan - the kind of cars with drinking habits closer to our depressing national fleet average (just over 20 mpg).
We chose three disparate vehicles but all with exactly the same EPA ratings: 14 mpg city, 20 mpg highway, 16 mpg combined. In the luxury category, we have the Infiniti M45x, driven by contributing writer Preston Lerner; playing for the sports cars is BMW's M3, piloted by West Coast editor Jason Cammisa; and representing SUVs, please welcome the inarguably full-size GMC Yukon, with senior editor Joe Lorio behind the wheel.
Our aim was to see who could get the best gas mileage piloting these profligate fuel swillers on a three-leg, daylong odyssey from West Hollywood, California, to Joe's Café in downtown Santa Barbara, then to Giovanni's Fish Market in coastal Morro Bay, and finally to the Texaco station just west of a huge oil field in Lost Hills. We allowed ourselves ten percent longer than Google Maps said the trip should take. To the winner would go honor, fame, and bragging rights - mostly the last one.
Gentlemen, start - but for God's sake, don't rev! - your engines.
Choose Your Weapon
0906 02 Z+2009 BMW M3+cammisa Lorio Lerner
Jason Cammisa: I don't know what's more ridiculous, the choice of vehicles (three V-8-powered gas guzzlers) or the choice of writers (three impatient native New Yorkers). If I'm going to have to spend five miserable hours in Los Angeles traffic, I'm glad I got the hottest car. The only thing "hyper" about me is my right foot, and I'm convinced that all the tricks these hypermiling weenies use are just plain dangerous. I'm seriously considering driving the M3 like a maniac, having a great time, and accidentally on purpose losing graciously.
Joe Lorio: Although it's the least fabulous, I'm not really disappointed to draw the Yukon. It's not as if we'll be able to use any of the performance of the M3 or the M45x. The four-wheel-drive Yukon appears to be at a disadvantage because of its size and weight, but it has a six-speed automatic (with a manual shift function), and although it's not the Hybrid version, its V-8 does have the ability to run as a V-4, so maybe that will help. Plus, it has satellite radio.
Preston Lerner: If we're going to spend the better part of a day in a car, then comfort is job one, and I'm happy to take the Infiniti. In preparation for this story, I started surfing various hypermiling Web sites and online forums. The best I found was ecomodder.com, and I took special note of its 108 - count 'em, 108 - tips for improving your fuel efficiency. To more closely monitor their effectiveness, I hook up a ScanGauge to the Infiniti's OBD-II port. This will give me an instant fuel economy readout, updated every two seconds.
Leg 1, Los Angeles to Santa Barbara
PL: On a three-by-five index card, I've prepared a cheat sheet with some of what seem to me to be the best of ecomodder's tips: DWB (Drive Without Braking), Lane of Least Resistance, and so on. I'm multitasking with a vengeance, trying to navigate traffic, figure out where I'm going, time lights, etc. - and not doing a very good job of it. I generally use the automatic transmission's manual mode to get into higher gears sooner. But the manual mode's separate gate prevents me from quickly throwing the car into neutral. Then, again and again, when I have the car in neutral at a stoplight, I forget to put it into gear after the restart and rev the engine uselessly, so that whatever fuel I've saved while stopping at the light is immediately wasted before I leave the intersection.
0906 03 Z+2009 BMW M3+mileage Monitor
JL: Heading west on Wilshire, I'm sticking to the right lane, which is the least crowded. The risk, however, is that one of the city buses up ahead might stop. So I keep one eye on my side mirror in case I need to hop over a lane, continually monitoring the bus for indications of a stop while also looking two or three lights ahead trying (futilely) to time them. This is relaxing.
JC: I decide not to cheat when I remember one fun rule of fuel-efficiency: the wider open the throttle, the less the pumping losses. The M3 has eight throttles, so in my twisted mind, the benefit of a heavy right foot will be eight times as big. I'll keep the revs under 2000 rpm and do all accelerating in the highest possible gear with the gas pedal on the floor, thank you. And I'll keep my speed below 55 mph once I get on the highway. No other nerdy tricks needed!
0906 04 Z+2009 GMC Yukon+mileage Monitor
PL: This ScanGauge thing is genius, at least for hypermiling devotees. I'm not sure how much it's actually teaching me, but watching the mpg numbers rise and fall is somewhat entertaining. 33.4! 44.1! 52.6! (Cue violin crescendo.) 9999!!! Joy is coasting down a hill.
JL: On a nice downhill, I see an indicated 99 mpg (evidently the max readout on the Yukon's instant-fuel-economy gauge). Hooray! Immediately, the traffic light at the bottom turns yellow. I could slam on the brakes and stop a few hundred feet short of the intersection (to preserve potential energy), but with a line of cars behind me, that seems unwise. Instead, I slow to a crawl, hoping the light will change, which it does - just as I stop and key off the engine.
PL: Onto the 405 North. I'm expecting major traffic, and I figure that my local knowledge will come in handy here. (Counterintuitively, the right lanes tend to move faster when it's congested going over the hill.) But there's no congestion to speak of, and the only slowdown is being caused by . . . me. I'm trying to keep my mileage in the high teens, and the only way I can do it is by dawdling along at 45 mph. Predictably, cars stack up behind me. Jeez, now I'm seeing 12.8 mpg at 42 mph. Inclines really, really suck.
JL: Finally, I enter the 405 North - average mileage through the city: 13.4 mpg. Oh, my.
0906 05 Z+2009 Infiniti M45x+mileage Monitor
JC: At 50 mph, I'm driving far too slowly to draft any trucks. They, like everyone else, are flying past me at 75 mph. Driving this slowly, even in the right lane, really highlights the ineptitude and inattentiveness of American drivers. They're either on my bumper, oblivious to how slow they're going, or they're visibly frustrated, with their heads spinning like Linda Blair's for miles on end trying to make a lane change. Hey, lady, ever heard of a rearview mirror?
PL: I select neutral as I crest the ultrasteep Conejo Grade. My speed increases gradually - and then not so gradually. Pretty soon, I see 85 mph. The ScanGauge is showing 231 mpg, and there's no way I'm slowing down while I've got all this momentum built up. DWB, baby! The only problem is that, to DWB, I have to weave back and forth among all three lanes - a video-game-like experience - to avoid tapping the brakes. Not only does this piss people off, but it confuses them as well. As I whiz past, I can see them examining me with a perplexed look on their faces. "Hey, isn't that the jerk who was doing 45 mph a few minutes ago?"
JL: The Yukon's V-4 mode is proving elusive. It appears when I take my foot off the gas, but the engine slips back into V-8 mode no matter how lightly I touch, graze, or even think about using the gas pedal.
JC: I turn off the engine heading down a huge hill, and the M3 accelerates to more than 90 mph. I'm getting a kazillion miles per gallon - at least for the moment - but, suddenly, stopped traffic causes me to start the engine so I can have power brakes. Only a few feet in front of where I stop, a truck has lost its load of plywood, and the cops have closed the highway to clear it up. I hereby demand a bonus 0.1 mpg to make up for the momentum I've lost. And decide I won't be switching off the engine at those speeds again; it's far too dangerous.
JL: The plan was to inflate the tires to manufacturers' specs when we fueled the cars just before starting out, but that gas station had a broken air hose, so it wasn't done. The Yukon's in-dash display shows 31 psi in all four tires, just shy of GMC's recommended 32 psi, but the huge tires look half inflated, and I can't shake the notion that they're bogging me down. I didn't see a place to fill them on Wilshire, and I didn't want to get off the 405, but now, on the 101 freeway, I scan each exit as I approach it, trying to spy a gas station right at the end of the off-ramp. Finally, in Agoura Hills, I get off. The sidewalls say 44 psi is the maximum pressure, so I go with that. Upon leaving, I discover that I can't turn left, back toward the freeway, so I go two blocks out of my way before I can turn around - thus wasting more gas than I'll probably save from the overinflated tires.
0906 04 Z+2009 GMC Yukon+mileage Monitor
Leg 2, Santa Barbara to Morro Bay
JL: At Joe's Café, I learn that my indicated 21.6 mpg is well behind Jason's and Preston's. Jason taped off the body seams on the M3, which is obviously giving him an advantage. So I give the Yukon the same aerodynamic makeover with blue painter's tape, masking the body seams and covering the entire grille.
JC: I'm in the only car without an instantaneous mileage gauge, but I realize that I can tailgate large vehicles at 65 mph using less throttle than when cruising at 50 mph on my own. I think the dude behind the wheel of the Chevy Avalanche pulling a camper doesn't notice me behind him - until he pulls into a rest stop just so he can lose me. I know that's why he exited, because he merged right back onto the highway. Oh, and he flipped me off.
PL: I check my cheat sheet and recall tip number 35: Find/Adopt a "Blocker" for Slower Freeway Speeds. This blocker, in formation behind you, is supposed to soak up all the road rage and rear-end collisions that would otherwise accrue to you. The only problem is that I can't find anybody going slowly enough to be my blocker; I'm literally the slowest driver on the road. In fact, I'm the slowest by far. I'm driving so slowly that I think I can see the asphalt aging.
JL: Desperate to wrest an advantage, I deviate from the 101, swinging west at Los Alamos onto CA 135 and Highway 1, which, although longer, will allow slower, more economical speeds. On CA 135, at a steady 40 mph, I'm seeing 26 mpg.
PL: One particular Advanced Technique (number 56) is Drive With Load, or DWL. The idea is to choose a target mpg figure and then progressively back out of the throttle to continue achieving it as you go uphill. I don't have a target per se, but I don't want to fall below 20 mpg. Unfortunately, this proves to be impossible to maintain on all but the shortest and shallowest hills. On longer, steeper ones, my mileage keeps dwindling: 21.2, 19.8, 18.1, 16.9, and so on. The only way to keep fuel economy from cratering is to ease off the throttle. But then speed bleeds off, of course, and the pace plummets with surprising rapidity when you're driving a two-ton sedan and you're not going that fast in the first place. I realize that the only way I can maintain my target fuel economy on a hill is if I lift off the gas pedal completely and let the car roll backward downhill.
JL: On an empty CA 135, I coast toward a flagman and he turns his sign around from STOP to SLOW. You said it, brother.
JC: A hitchhiker, thinking I'm slowing to pick him up, grabs his bags and starts walking toward my lane. He looks disappointed as I dawdle past him in my 414-hp M3.
0906 07 Z+lorio Unburdening+2009 GMC Yukon Of 3rd Row Seating
Leg 3, Morro Bay to Lost Hills
JL: It occurs to me that, when we chose the Yukon for this exercise, we hadn't specified the eight-seat version, but that's what I'm stuck with, and this is an unfair disadvantage. So, while Jason and Preston are eating snacks and gazing out at Morro Rock, I remove the Yukon's two third-row-seat sections and place one in each of their trunks.
JC: On the way out of Morro Bay, I realize that the BMW's dual-clutch transmission will let me into seventh gear as slow as 28 mph, which is about 1000 rpm. Full throttle at these engine speeds results in a faint V-8 pitter-patter that sounds like tinsel tickling the exhaust headers' thin walls. Oh, what I'd give for just one run up to 8000 rpm.
JL: I start this leg with the same, lousy 21.6 mpg average with which I started the last one. I'm way behind the M45 and the M3 in mileage and have chewed up more drive time to boot. So in a desperate Hail Mary play, I am again taking an alternate route, staying on CA 41 all the way to CA 46, this time cutting off a significant chunk of distance but possibly setting myself up for a steep climb and winding mountain roads east of Atascadero. We'll see.
PL: I leave Morro Bay on a twisty, picturesque two-lane road that would have been driving heaven - were it not for the fact that I'm trying to hypermile. Inevitably, cars stack up behind me. There's no place to pull over. On several occasions, I edge over onto the shoulder, giving a clear signal for the cars in my wake to go for it and safely make the pass. But the ones immediately behind me continue to behave like lemmings. Beyond them, I imagine, other drivers must be suffering from whatever comes after road rage (road apoplexy?).
JL: Turning toward Atascadero, sure enough, big, green mountains are looming up ahead, and they are certain to drag the Yukon's fuel economy down into the single digits. I am trying to keep this beast in sixth gear, but the transmission's manual mode is just a placebo, kind of like the CLOSE DOOR button in an elevator. You can move the shift lever to M and punch the upshift button until you see M6, and that's what remains on the display, even when you come to a stop, and even when you pull away in what is obviously first gear.
0906 08 Z+2009 GMC Yukon+losing Finishing Numbers
PL: I try another Advanced Technique in the hills between Paso Robles and Lost Hills - the P&G, for Pulse and Glide. Instead of trying to maintain a constant rate of fuel burn, I build up a head of steam, then coast on the kinetic energy. Supposedly, this was the secret weapon used by a group of hypermilers who recently got 109 mpg out of a Toyota Prius. Unfortunately, there's no way for me to figure out if I'm achieving a net benefit.
JL: Although the post-Atascadero, shortcut part of CA 41 has been blessedly empty, I eventually catch up to a vehicle moving even slower than me: a rusty dump truck that looks like it's going to keel over. Just before we get to a section of switchbacks, I do a wasteful, but highly satisfying, full-throttle (2 mpg!) pass and blow by him. I justify it by rationalizing that I can't afford to be stuck behind this guy and lose the big mo I'm going to get on the downhill side of this mountain.
JC: On two-lane CA 46, I have the choice between blocking traffic at 50 mph or drafting trucks at 65. I try both and can't decide which annoys people more. Oh, but I do learn what makes people freak out the most: passing them downhill at 80 mph after they've just passed me going 40 uphill, and then having them pass me again when they catch up to me doing 50 mph on level ground. I blast the stereo to drown out the honking.
JL: In the final hour, I manage to do a stretch on CA 46 in four-cylinder mode, going just barely 60 mph at an indicated 34 mpg - while in the distance ahead there's not one but two rainbows. It is a magic moment, but without a team of unicorns to tow the Yukon, engine off, to the finish, it's not magic enough.
Afterward
PL: Fuel-efficient driving may be a useful and worthy technique, like heel-and-toe downshifting and clipping apexes, that enthusiasts can and should employ on occasion. But we turned it into a contest, like tennis or automobile racing. The difference between hypermiling and these other sports is that there's nothing intrinsically fun about it. Think about it: You can play tennis for pure enjoyment, and racing's a thrill whether you're winning or not. Not only is hypermiling not fun, being good at hypermiling demands that we give up much of what we enjoy most about driving. In other words, it sucks the fun out of the driving experience. So it is by no stretch of the imagination a sport. It's more like trying to ace your SATs.
JL: The contest over, I head down I-5 back to L.A. - at a cruise-controlled 75 mph. Although I almost never use cruise control, after nearly seven hours of the most delicate gas-pedal manipulations, I have never been happier to drive with both feet flat on the floor. The GMC Yukon is getting a measly 16 mpg, and I couldn't care less.
JC: The BMW M3 may have the most horsepower of the group and the shortest gearing, but it's also got the smallest engine. Apparently, when it comes to hypermiling, there's no replacement for lack of displacement - and the other boys' little tricks didn't do squat. At 25 mpg overall, I beat the EPA combined fuel economy figure by 56 percent - and that includes extricating myself from Los Angeles in 8 a.m. traffic. I've now learned the fine art of hypermiling, and, like calculus, it's a discipline I vow to never, ever practice again. I celebrate by doing three donuts around Preston's M45x and leave the parking lot sideways.

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2009 BMW M3

Base RWD 4-Dr Sedan V8
starting at (MSRP)
$54,850
Engine
4.0L V8
Fuel Economy
14 City 20 Hwy
2009 BMW M3