The Indictment - A 2011 Hyundai Sonata is unable to deliver anywhere near the EPA city estimated 22mpg in suburban driving.
Chris Bernius - CleanMPG
- Feb 26, 2011
On The Docket Today
The 2011 Hyundai Sonata with six speed automatic is EPA estimated to deliver 22mpg city and 35mpg highway. One sample of this family sedan is accused of being unable to achieve anywhere near its 22mpg city rating in suburban driving. The indictment specifies that highway fuel economy is satisfactory - close to, or meeting, the highway EPA figure. Duly note that the inability to achieve the rated fuel economy during daily commute was carefully measured during an unusually harsh winter season, with temperatures averaging 15-35F. Fuel economy was calculated as miles on the odometer divided by gallons pumped into the tank at fillup, generally regarded as the most accurate method of obtaining the real number. Also note the EPA test - known as FTP75 - is a standardized data collection performed on a dynamometer. Every passenger car model sold in the USA is driven on this cycle as part of its emissions certification. Each make and model is tested using the same method, and the results are adjusted and rounded, and the result is displayed on the Monroney sticker of new cars. Duly note that the defendant has roughly 1000 miles on the odometer, so the engine has not yet "loosened up". It is not uncommon for modern direct-injected engines to take up to 5000 miles to "wake up" and deliver even better fuel efficiency.
Originally Posted by Feb 4 2011
My wife and I have over 700 miles on the car. We drive it about 70% surburban (not city) and 30. We are very conservative drivers, accellerating and braking very gently we don't speed, never exceeding the speed limit by 10%. It is mostly used with temperatures in the 30s. We use brand name gasoline of the recommended octane. The air conditioner is never on and the windows are closed choosing instead to use the car's filtered air coming through the vents. We never tow anything behind the car, the trunk never has more than a few bags of groceries and at most there is one adult and one toddler passenger. The tires are at 32psi.The car never idles more than 30 seconds except perhaps at traffic signals.
I think I have addressed all the mpg variables above. My wife and I are achieving 13.x mpg, all types of driving combined. We have used several different methods to measure mileage. Hyundai used their own unrealistically conservative test and got 16 mpg.
Originally Posted by Feb 5 2011
Every drop of gas since I bought the Sonata has been documented and I have receipts for same along with photos of the odometer and the avg. mpg display along with notes about driving type (city or highway or mix) and photos of the odometer and avg. mpg as it may have changed a bit since the last trip.
My average of 13.x mpg is well documented. The dealership service manager said of his city driving test of 2 miles he achieved 23.8 mpg. When I arrived home (exactly 5 miles) the avg mpg, having been reset before he ran the test, went down to 13.4 mpg.
Originally Posted by Feb 6 2011
Could the mpg have gotten worse? Well yes it could have. On the current tank of gas only 40% or so has been used, but already over the course or 9 or so gallons we're averaging 11.5 mpg.
Originally Posted by Feb 9 2011
Our 2011 Sonata GLS gets an average of 13.5 mpg. Just to be thorough, we drive 60 mph on the highway, in the "city" there is no hard acceleration or braking. There's nothing in the trunk, no towing, not more than two passengers, no A/C on, and no windows rolled down. The tires are inflated to 32 psi as per the manual's recommendation and the fuel is brand name of the octane rating recommended in the manual.
We have garnered these results over the 900 or so miles the car has on it. I have both used the Sonata's average MPG display and via meticulous record keeping of gallons filled into the tank over the course of the car's life.
All other things being even, we bought the car because of the mileage. If we wanted this kind of mileage we could have bought a big truck with a massive V-8. Shame on you Hyundai.
Originally Posted by Feb 11 2011
Hyundai fights me telling me the car is operating within design specifications on the one hand and actively embraces and promotes the EPA MPG results on the other (in their advertisements and commercials).
Writ of Habeas Corpus
Originally Posted by Feb 12 2011
Hyundai's District Managers T** L**** and G****** P***** drove in my Hyundai in what they term "city" testing. The EPA's methods for determining 22 mpg city are much harsher. In our test there were no cold starts and there were no hard accelerations nor hard stops. There couldn't be. The ground was slippery, so accelerations were gentle and we had to glide at 2-3 mph into stop signs. We were in the middle of a snow storm. The results of that test, that Hyundai is not in dispute of, using a completely different method to compute fuel consumption were 16mpg.
Literally "You are to have the body" - And in this case, we're "puttin' on the writs" here and now just so we can see that gorgeous body.
Ladies and gentlemen, the defendant in this case, looking resplendent in Radiant Silver.
Jury selection was performed by googling "Perry Mason" and choosing this image.
Swearing In The Plaintiff and Defendant
This is a family-friendly courtroom, so we won't be swearing, unless one one of the attorneys drops the gavel on their foot.
In the spirit of maintaining this family-friendly atmosphere, sitting on the bench today will be an Article III judge, so-called because s/he is wearing at least three articles of clothing, not counting flipflops.
The Facts Of The Case
- EPA test FTP75 - the official measure of the EPA city fuel economy number - is outdated and didn't reflect real world urban driving even in the mid 1970s, when the average compact car weighed 3100 pounds and had a 90-110hp inline six with one or two barrel carburetor and measured 0-60mph in roughly 15 seconds. The disclaimer of "your mileage may vary" wasn't cutting it, so the EPA has since introduced adjustments - twice. In 1985 and again in 2008, the original EPA mileage numbers gathered during dynamometer testing (and used for CAFE calcluations) have been adjusted down to lower numbers that are "more realistic" in today's world.
- The 2011 Sonata is a midsize sedan that is rated by the EPA as a "full size" thanks to its generous 120+ cubic feet of interior passenger and trunk volume. Although it is among the lightest vehicle in its segment, it's still a heavy car compared to entries in the B and C segment (subcompact and compact cars). Its class-leading 35mpg highway is the result of a tall overdrive sixth gear and a body shape that is optimized for a very low coefficient of drag. Note that these attributes don't aid fuel efficiency during low speed commutes. Also note that the midsize 2011 Sonata GLS, at 3200 pounds, is still a comparatively heavy car. And so heavy stop-n-crawl traffic along congested routes will cause an inevitable shortfall in measured fuel economy.
- The powerplant for the 2011 Sonata is an advanced 2.4 liter 16 valve engine with continuously variable valve timing and GDI - Gasoline Direct Injection. The direct injection technology allows significant increases in fuel efficiency and decreases in emissions - especially cold start emissions.
- The automatic transmission in the 2011 Sonata is a six speed unit based on the familiar Lepelletier gearset. Like most similar units, it uses a fairly tall 2.885:1 final drive, but has a "rock-crawler" first gear (4.212:1) to provide acceleration strong enough to please customers and the automotive media. Second gear, at 2.637:1, is close to the first gear of most three, four, and five speed automatics. Hyundai's first "designed inhouse" automatic offers excellent highway fuel economy via its 0.772:1 overdrive sixth just above the direct drive fifth gear. In order to minimize the fuel economy impact caused by the rock-crawler low gear of any modern Lepelletier-based automatic, it is wise to fake shift these new six speed automatics by lifting off the throttle slightly when the tach approaches "2". But very few drivers know that this technique exists to overcome the guzzling introduced by the "auto-media-friendly" first gear.
- As temperatures fall, fuel economy necessarily falls as well, for several reasons. Colder air is more dense than warm air, which increases air drag on the car. Low temperatures increase tire rolling resistance, regardless of tire inflation pressure. And low temperatures increase the viscosity of the various lubricants used throughout the driveline, leading to increased energy losses in the powertrain.
Existing Laws Relevant To The Case
- The laws of physics tell us that "force = mass x acceleration". More mass needs more force. More acceleration needs more force. Increase both (relatively heavy car with strong acceleration), and the force required is that much greater. The energy for this force comes from gasoline, and so requiring more force necessarily means using more gasoline.
- Kinetic energy is equal to mass times velocity times velocity, divided by two. Energy therefore increases with the square of speed, where doubling speed requires the unleashing of four times as much potential energy in order to accelerate to that speed. In a vehicle powered by gasoline or diesel, potential energy is stored on board in the fuel tank as a liquid hydrocarbon. The potential energy is released from the fuel and converted into kinetic energy by burning the fuel in an internal combustion engine (ICE for short), where the torque - or twisting force - is multiplied via gear reduction and then applied to the drive wheels. Increasing the vehicle mass by 33% means 33% more energy is needed to propel the vehicle to a given speed, so heavier midsize vehicles (assuming identical powertrain efficiency) cannot match the fuel economy of lighter compact vehicles when both are driven in exactly the same manner.
- Stepping on the brake pedal converts kinetic energy (gained by burning fuel) into the potential energy of heat on the brake rotors. There are two ways to stop a vehicle in motion - Apply the brakes, or steer into an immovable object.
Consider the following image, showing a test conducted by NHTSA, involving the 2011 Sonata stopping "the hard way", and earning five stars in the process:
The purpose of the image is to graphically reinforce the concept of just how much energy needs to be thrown away every time a driver presses the brake pedal to stop from 35mph. The energy lost is enough to crush more than eighteen inches of high strength steel. And this same kinetic energy, obtained by burning irreplaceable petroleum every time you step on the "tall" pedal, is lost forever every time you step on the "wide" pedal.
- Gerdes v. Downtown Chicago
(06/29/2009) - The 2010 Ford Transit Connect, wearing EPA ratings of 22/25 on its Monroney sticker, delivered 11.3mpg in the stop & crawl of downtown Chicago.
Originally Posted by Entered into evidence
These poor results were achieved in stop light/sign to stop light/sign mid-day driving (with A/C!) through the worst that downtown Chicago had to offer. The first segment included approximately one mile on I-90/94... which was also a jammed in stop and crawl. Total distance for that trip was approximately 3 miles. The second segment was similar and covered roughly 2 miles.
Basic and Intermediate techniques were employed to achieve these results. These consisted of two Fas at lights for the first trip, and 4 Fas at lights for the second. In that kind of traffic it was abundantly clear that in order for small businesses to avoid the waste and costs associated with inner city delivery using conventional vehicles, all-electric solutions will have to be adopted.
- Gerdes v. Yukon
(06/03/2008) - A 2005 GMC Yukon XL 4WD, rated by the EPA at 13/17, was driven in downtown Manhattan during a demonstration of hypermiling for Miles O'Brien, a reporter for CNN. The reporter, stating that basic techniques instantly reduced his fuel consumption by 30%, still listed 10.6mpg on the ScanGauge. That would indicate that "normal driving" in midtown would have resulted in roughly 7.4mpg - a stark contrast to the 13 on the window sticker.
Order To Show Cause
On a sunny Saturday - Feb 26 2011, between 1:00pm and 3:30pm - The defendant was cross examined in the presence of the prosecuting attorney.
The weather during this examination was sunny, with temperatures in the range of 40F-45F, and light winds varying N to NNE to NE at about 10mph. The test commute was predominantly east-west, and closely spaced buildings in the dense urban area effectively mitigated the effect of wind.
To review: The defendant is a 2011 Hyundai Sonata GLS, 2.4L with six speed automatic. No modifications of any kind, and stock wheels and tires are in place. Odometer mileage was 1153 at start and 1171 at completion.
Tire pressures - (cold, before initial startup), via Accutron digital pressure gauge:
L-F [37.5] R-F [37.0] L-R [33.0] R-R [34.5] - Placard: 32 F / 32 R.
Result=PASS (for the purpose of minimum tire pressure needed for adherance to FTP75).
Test Procedures and Results
Drivers : Chris (MaxxMPG), Owner (Owner of the Sonata), Witness (Relative of the Owner)
Purpose : Replicate a "daily commute" as closely as possible to measure fuel economy under known conditions.
- Saturday afternoon traffic, while heavy, can't hold a candle to the absolute murder of the same route on a Monday morning.
- Daily commute, and EPA FTP75, include only the driver in the car. During these tests, there were one or two passengers as well. One of the drivers/passengers, who shall remain nameless, weighs more than the average passenger and in fact enjoys lifting car engines as much as he enjoys discussing them. Note that added weight will degrade fuel economy whether it is part of the car's curb weight or if the car is loaded with one or more big bruisers.
- In order to "drive like the EPA" so that a real-world result can be measured, the test drives were performed with the car in Drive at all times, and the engine running at all times during the trip. No coasting in neutral and no shutting down at long traffic lights.
- The EPA test is performed with all fuel economy enhancements disabled. The drives were completed with the Eco mode switched off.
- The speed limit on the main road used during the test is 40mph, and the maximum speed during all test was observed as about 42mph on one stretch, but most of the trip was completed at speeds of 15-25mph.
- EPA tests are conducted using straight gasoline, while New York State mandates the sale of Johnnie Walker Gold (20 proof). This alone is responsible for fuel economy degradation of 5 to 10%.
Note 1: #Stops represents the number of "stop signs" or other traffic events requiring a stop for only a second before proceeding.
|Parameter||Test 1||Test 2||Test 3||Test 4||Comment/Footnote|
Description ||"Home to Work"||"Work to Home"||"Home to Work"||"Work to Home"||Exact commute car drives every weekday|
Driver ||Owner||Witness||Chris*||Owner*|| *-Basic hypermiling: only DWL, DWB, Light Timing, Smart Braking|
Total aboard (incl driver) ||3||3||2||2|| Three are listed above under 'drivers'|
Engine Temp at Start ||COLD||HOT||HOT||HOT|| UG reported 52F coolant for test 1, >190F for tests 2,3,4|
Start/End odometer ||1153-1158||1158-1162||1162-1167||1167-1171|| As measured from car's odometer|
Start/End time (hh:mm) ||1:28pm-1:50pm||1:53pm-2:13pm||2:32pm-2:52pm||2:58pm-3:20pm|| As measured from a $7 Sharp quartz watch|
Trip Time (minutes) ||17||19||19||21|| As displayed on UG|
#Stops(qty)/#Idle(qty@sec;min)|| 15 / 14@355;5.92 || 13 / 13@335;5.58|| 4 / 9@300;5.0 || 7 / 13@360;6.0 || See Note 1 and Note 2 below|
Idle Time (% of trip) || 34.8% || 29.4% || 26.3% || 28.6% || Calculated as (idle time / trip time) x 100, not counting 'stops'|
Trip Distance (miles) ||4.5||4.7||4.5||4.6|| As displayed on UG|
Trip Avg Speed (mph) ||15.5||14.0||13.8||13.2|| As time progressed, traffic increased in both directions|
Trip Miles Per Gallon || 15.2 || 16.5 || 19.7 || 18.2 || See Note 3 below
Note 2: #Idle represents red lights, waiting to make left turns or for traffic to clear, or any other stop event that takes more than a second before proceeding. Only stops of more than 5 seconds were noted, with the number of seconds written down each time. The sum of these numbers is shown here, in seconds and fractional minutes.
Note 3: During tests 2 and 4, the UG was displaying roughly 10% more than the final MPG average, but fell to the final result due to a traffic light with a long red and short green, resulting in waiting for two light cycles before proceeding. On a daily commute, waiting three or four light cycles would be typical.
Comparison of Four Tests vs EPA FTP75 ("City" test) :
Entered into evidence
|Parameter||EPA FTP75||Test 1||Test 2||Test 3||Test 4||Comment/Footnote|
Description ||EPA Baseline || "Home to Work"||"Work to Home"||"Home to Work"||"Work to Home"||Exact commute car drives every weekday|
Top Speed || 56mph || 42mph || 40mph || 35mph || 40mph || Casual Observation of speedometer - not 100% certified|
Total aboard (incl driver) || 1 || 3 || 3 || 2 || 2 || Three are listed above under 'drivers'|
Engine Temp at Start ||WARM||COLD||HOT||HOT||HOT|| Test temp of 40F means warmup hit not too bad compared to EPA's 70F|
Trip Time (minutes) ||31.2||17||19||19||21|| Time is less than EPA FTP75, but it's 1/3 hour of survival-mode driving|
Trip Time (% of EPA) || ---|| 54.5% || 60.9% || 60.9% || 67.3% || Our test time roughly 6/10-7/10 that of EPA|
Trip Distance (miles) ||11||4.5||4.7||4.5||4.6|| Distance is less than EPA FTP75, but a grueling commute|
Trip Distance (% of EPA) ||---||40.9%||42.7%||40.9%||41.8%|| Our test distance is roughly 4/10 as far as that of EPA|
Trip #Stops||23||29||26||11||20|| # for our tests include #stops + #idle events|
Trip #Stops (% of EPA) ||---|| 126.1% || 113.0% || 47.8% || 87.0% || Note DWB and Light Timing effect in tests 3 & 4 |
Trip Idle Time (% of trip) || 18% || 34.8% || 29.4% || 26.3% || 28.6% || Much more time idling in metro NYC!|
Trip Idle Time (% of EPA) ||---||149.5%||164.4%||132.2%||151.7%|| Our tests had much more idle time than EPA FTP75|
Max Acceleration || 3.3 mph/sec || sometimes || not often || yup, darn close || gettin' better! || not measured in test, subjective values assigned
- The technical information for EPA test FTP75, submitted for data verification.
Entered into evidence
- Images of UltraGauge showing the results of Test 2 and Test 3 above.
Here's a sidebar for all you lurkers, motor-heads, and chronic speeders here in the courtroom, who complain that "Hypermilers are dangerous because they go too slow and hold up traffic", and "Hypermiling wastes my time - I can't hypermile because I will be late for work". Look at that image above - This one's for you! The left side - representing normal driving by "witness" - shows an average trip speed of 14.0, and the right side shows my result of 13.8. Really?! I selfishly obstructed traffic by going .2mph slower? Really?! Oh, wait. I wasted a lot of time with my selfish hypermiling, didn't I? Oops... Run time for both legs is identical, at 19 minutes. Yes, one leg is 0.2 miles longer than the other, but the difference would be a matter of seconds between the two runs. Oh, and here's the punchline for the motor-heads and speeders. Fuel consumed on the trip - 0.28 vs 0.23. While 0.05 gallons doesn't sound like much, multiply it by 56 for the number of trips to/from work/shopping/errands in four weeks and you get 2.8 gallons, or $10 at $3.60 a gallon. So if our trip average mph was about the same, and time was about the same, and brake and drivetrain wear were concurrently reduced, what selfish motivation could remain for burying the pedal and trying to get to that red light a few seconds sooner? Note - The gauge reading on the left, measured during the drive by "witness", was a normal everyday drive in NYC, and his driving was safe, rational, and in every way within the range of NYC drivers. An actual motor-head or speeder driving in this test's environment would be in the 10-12mpg range, or even less. So please note that this sidebar is not describing any of the three test drivers here, but only those reading this text who still feel it is their God-given right to floor the accelerator as often as they want, which would usually be when they forget to take their medication.
Entered into evidence
- The Beast With Seven Horns (or shall we say Six Lanes?) - Northern Boulevard in Queens, an outer Borough of New York City. In each direction, there are three lanes, used for the following purposes: Right - Used for parking. Left - Used as a left turn lane. Even when left turn lanes are available, the left lane is used to place the rear half of the vehicle waiting to turn while its front half is in the left turn lane. Center lane - slaloms between the left turners and the cars leaving parking lots, blinded by the cars parked nose-to-tail in the right lane, nosing out until traffic has to stop so they can enter the road.
First image of Northern Boulevard - Don't be deceived by the space between the Sonata and the Civic ahead - that's just DWB in action. Look ahead to see the clogged artery upon which we're doing battle. Please note cars parked in the right lane, lest you think we're making this stuff up. What a mess - and it's only Saturday!
Second image of Northern Boulevard - Another shot of the dreaded NoBo - for those who enjoy studying details of a photo. On the far right is a Focus double parked in the center lane
because the right lane is already full of parked cars. To the right of center, under the big tree, is a gold Windstar doing the nose-out inch by inch until he either gets clobbered or can get traffic to stop so he can nudge through the parked cars in the right lane and into the center lane. In the original high-res photo, you'd see that there is a Caravan in the center lane behind him, half in the traffic lane, waiting to get into the lot after the hapless Windstar is able to drive out. Reminder - This is light Saturday afternoon traffic. A weekday drive-time photo would reveal the full fury of congestion at its worst.
The tests reveal some interesting conclusions. First, the EPA "City" test reflects a utopian city that existed circa 1974. The poor slob on the dynamometer would be eaten alive on any clogged artery in or around New York, LA, Chicago, Atlanta, Boston, or any other major city. The EPA City rating has been adjusted twice over the years, and is now accurate for more drivers. But anyone whose commute is less than 5 miles, requiring 20-25 minutes and sometimes more, is not going to see the EPA rating anywhere on the road unless they happen to be glancing at their window sticker.
Our tests were broken down into four individual segments - The owner driving from a cold start, then the witness driving back home. This provides results for two ordinary/everyday guys in the "defendant" Sonata. The third result is me driving the same car, on the same route, with the handicap of "engine always on, car always in drive", no downshifting for fuel cut (brake pedal only), no use of the ShiftTronic capability, and no Eco mode. It was just me "workin' the crowd" and doing everything I could to avoid having to stop at any of the horrible 35-75 second red lights. The fourth test was again the owner, now receiving some CleanMPG coaching, and responding to the guidance. This final leg resulted in a fuel "gal/hr" of 0.72 versus my 0.70 and his original (albeit "cold start") 1.03 gal/hr. This result indicates that techniques shared at CleanMPG are indeed contagious and anyone who wishes to "catch it" can certainly begin to employ these same proven strategies for the benefit of their wallet, the country, and the planet.
By simply changing a few parameters in the driving environment, the defendant (still looking resplendent even with an extra 18 miles on the odometer) delivered measured fuel economy within 15% of the EPA estimate. Furthermore, the car was very close to EPA on the last test before reaching the Traffic Light of Doom, so called because it required waiting for two long light cycles in order to move beyond the intersection. The extended wait time, with engine idling, knocked almost 2mpg off the final average. Changing the driving route to avoid this light would likely restore that 15% overall loss and allow the defendant to deliver fuel economy startlingly close to its city EPA rating, even at a chilly 40 degrees.
The defense rests.
Jury Deliberation aka Twelve Angry Men
Since our jury is simply a monochrome image of movie extras and guest stars from the golden age of television, we're not missing much by sending them off into their chambers. Once inside, they will be dreaming about how to spend the $50 a day they will be getting, while perusing the available polystyrene-based luncheon material served in greasy cardboard containers.
Ok, jury. Heads up. The judge has ordered you back into the courtroom.
What could it be? The closing statements have been made, and all the evidence has been entered into the record.
Ladies and gentlemen, before the jury could deliberate and a verdict could be rendered, the prosecution has moved to withdraw the charges. Having seen the results of the testing, the case has been made that the defendant - a 2011 Hyundai Sonata GLS - is cleared on all charges and would indeed be able to deliver its EPA estimated 22mpg, if the test were performed according to the EPA test procedure. The fact that the car approached 90% of EPA on a chilly winter day, driving a commute upon the Road of Perdition aka the Turnpike of Torment aka "Rt 25A", the prosecution has been satisfied that the Sonata is indeed a capable and comfortable commuter car.
Originally Posted by Prosecution
As much as I hate to admit it, you were right. Changing the way the car is driven can improve the mileage enough to convince me that it is within spec.
I have to admit that when I visited CleanMPG, my intent was to warn potential Hyundai customers that the Sonata can't meet its city mileage number. I had visited other sites before as well, writing the same thing. Your site was the first and only one to respond to my post with "we can help". And I really appreciate the fact that you came here to help me sort this out. I have never seen a fuel economy test done with such precision and detail. You have convinced me.
Final statement from the Defense
The folks at CleanMPG have had their share of experience with the 2011 Sonata and it has continued to impress us with its class-leading style, safety, room, comfort, segment-busting value for the dollar, and of course - outstanding fuel economy potential. One of CleanMPG's earliest encounters with the 2011 Sonata was measuring over 64mpg while driving one 1000 miles on 2/3 of a tank
, from central Wisconsin to near the end of Long Island, NY.
"So, can I go home now, your honor? This gray wool blazer is really itchy."