Home / Auto News / News article: Turbocharged Cars Don’t Live Up to Fuel-Economy Hype Says Consumer Reports - AutoGuide.com News
 |  Nov 02 2012, 2:43 PM

Vehicle quality was not the only thing making news when Consumer Reports unveiled the results of its latest reliability study in Detroit earlier this week. Amongst the issues highlighted by the consumer publication were real world fuel economy and forced induction engine technology.

In particular, the watchdog organization took issue with downsized, turbocharged engines, citing efficiency and reliability issues with certain engines during real-world testing.

Currently, automakers are in a race to the bottom, slashing engine displacement and bolting on boost to help meet ever-stricter fuel-economy standards. Brands like Hyundai and Ford are seen to be leading the charge with turbocharged powerplants in mainstream products like the Sonata and Fusion.

“Engine downsizing is the biggest driver for turbocharging, along with direct fuel injection,” said Tom Grissom, Director of Business Development for BorgWarner Turbo Systems. He said they’re essential to giving smaller engines the performance characteristics drivers need.

Ford-EcoBoost-Turbocharger.jpgBorgWarner sees big growth potential for turbos in North America. Grissom said, “the U.S. is fundamentally a gasoline-fueled passenger car market.” As automakers downsize engines they will have to turn to turbos. Europe’s vehicle fleet is already predominantly diesel powered, which means turbochargers are already on most engines there.

Bosch Mahle Turbo Systems, another major supplier of turbochargers to car manufacturers, projects that by 2019, 45 million turbochargers will be used in passenger vehicles annually.

LAB RESULTS, NOT THE REAL WORLD

Part of the discrepancy noted by Consumer Reports and documented anecdotally in AutoGuide reviews may come from the fact that so called “window sticker” fuel-economy numbers provided by the Environmental Protection Agency (EPA) are achieved through tests done in a lab, rather than on the street.

In the EPA test cycle vehicles are strapped to a chassis dynamometer, their drive wheels positioned on a series of rollers. The energy it takes to spin these rollers can be adjusted to simulate extra vehicle weight or wind resistance.

Once a vehicle is securely mounted on the dyno, a professional driver takes it through a series of simulated routes, accelerating and braking according to the standardized test schedule. Fuel economy ratings are determined by measuring the amount of carbon exhausted out the tailpipe. Obviously this methodology doesn’t work with electric vehicles.

Since 2008 the test has been amended to include additional variables, things like higher driving speeds, cold temperatures and air conditioning usage.  These tweaks help the EPA test more accurately reflect real-world performance.

When contacted to see if new changes should be incorporated to close the gap between as-tested fuel economy and real world fuel economy on turbocharged cars, the EPA did not immediately respond. But given Hyundai and Kia’s recent trouble in this area, things may change in the future.

On paper the downsized-turbocharged formula really works to improve fuel economy. New-vehicle shoppers see bigger numbers on window stickers, but this is not something the folks at Consumer Reports found in their testing.

CHEVY CRUZE, FORD F-150 SINGLED OUT

Two examples cited are the Chevrolet Cruze compact car and the Ford F-150 pickup, both of which offer optional force-fed engines. Jake Fisher, the Director of Auto Testing at Consumer Reports said that even with downsized, turbocharged engines “[they deliver the] same fuel efficiency as their normally aspirated counterparts.” This calls into question the fuel-economy improvements automakers have made the last few years.

2012-Ford-F150-Front-Three-Quarter.jpg“EcoBoost had virtually the same zero to 60 time and 15 miles per gallon as the V8,” Fisher said of the F-150.  This is not exactly a ringing endorsement of blowers and direct injection, given their added cost and complexity.

These engines have also proven to have reliability issues. According to Fisher, when it first came out, “the Mazda CX-7 turbo had a lot of problems… but they ended up working them out.” Also, “in previous years the WRX and other turbocharged Subarus were below average in reliability.”

Even premium brands have had some trouble in this area.  Fisher said, “there were some early problems with BMW’s 3.0-liter turbo engine.”

Under-hood troubles can impact quality scores, but there are other factors to consider. Turbocharged powerplants are often found in higher-trim models. Typically these vehicles are delivered with extra options, which means there are more things to go wrong.

EPA standards are the law of the land so automakers follow them to the letter. As for the Chevy Cruze’s performance in Consumer Reports’ testing, Tom Read of GM Technology and Powertrain Communications said “based on their drive schedule they may have come up with something different from the EPA numbers.”

“The EPA numbers we report on are clearly better with the 1.4 turbo – 26/42 [miles per gallon] with the eco model versus 26/38 with the 1.8,” Read said.

2013-Chevrolet-Cruze-Front-Three-Quarter.jpgRichard Truett, Powertrain Communications Manager at Ford echoed these sentiments. He said “a lot of it depends on how consumers use it” and “we’re discovering that people really enjoy the turbos.” In other words, buyers like the rush of acceleration they offer.

According to Truett, the 3.5-liter EcoBoost V6 offered in the F-150 can deliver superior fuel economy to the company’s the 5.0-liter V8 engine “if you use the turbos smartly.” He also said you can’t have your cake and eat it too; you have to keep a light foot on the throttle to maximize efficiency.

Lower-than-expected real-world MPG numbers don’t appear to be dissuading buyers from opting for boosted pickups. Truett said as of last month “EcoBoost alone is about 42 percent of F-150 sales,” adding “it’s exceeded all expectations of sales and performance.”

Summing things up, Read offered some advice, “no drive schedule can be perfect to simulate what a customer is going to get, but [EPA scores are] better than ever as an indicator of what a customer is going to get.” As always, you mileage will vary.

  • http://www.facebook.com/andrewpeabodyusn Andrew Peabody

    I think people are focusing on the wrong aspects of this. Take the Ford for example. True, you’re getting the same zero to sixty times and mileage as the V8 counterpart, but you’re using a V6 that produces less emissions and is more mechanically efficient because of the scavenging from the turbochargers. Less parasitic loss is always good, and the fact that we’re still working on evolving these systems means those mileage numbers can easily go up. More tuning can make this happen, but it’ll most likely happen on a computer, not on the engine itself. Don’t be too keen on ridiculing the system yet…

  • John Elegant

    I have a 2012 1.4 L turbocharged Cruze, and just turned 12,000 miles on it. Am averaging over 40MPG (combined), so don’t know what Consumers Reports is saying of turbo cars not getting real world actual mileage. My cars has thus far exceeded GM and EPA average fuel mileage claims.

  • http://www.facebook.com/andrewpeabodyusn Andrew Peabody

     I’ll confirm this- I also had a Cruze last year and even with many modifications, I was actually getting close to 50MPG highway (calculated, not on the DIC)

  • D135

    If two cars have the same fuel economy would they not have the same CO2 emissions?  How can you say the turbo produces less emissions yet has the same fuel economy as the V8?

  • justYncredible

    I have to agree, with a quality tune you will see an increase in mileage per gallon. I rebuilt my integra gsr to support a turbo. I average around 33-36 miles per gallon and with full interior! Thats almost 10 miles more than the stock motor. It’s all in the tune!

    Also, some people have a heavy foot and like to see boost!

  • http://www.facebook.com/andrewpeabodyusn Andrew Peabody

     I’m saying the V6 has lower emissions than the V8- Ford claim that they’ve achieved “reduction of CO2 emissions of up to 15 percent, compared with larger, less-efficient engines.” (http://media.ford.com/article_display.cfm?article_id=33807) One would assume that they’re comparing to their own Triton V8 5.0L which is the other option for the F-150. A smaller engine will create less emissions with or without the turbo, but the turbo helps to keeps the power levels similar to what you would get with a larger, more traditional engine.

  • http://twitter.com/BradleyGroot Bradley Groot

    I want a car I can drive with a “heavy right foot” that has 200+hp and gets 30mpg, you’re telling me turbos ain’t that?

  • D135

    Well I was just curious about your comment about a smaller vs. larger engine producing different amounts of CO2 yet having the same fuel economy.  One gallon of gasoline burned produces a fixed amount of CO2 (I believe 19 lbs) so if two cars have identical fuel economies, regardless of what size engines they have, they should produce the same amount of CO2, right?

  • Michael Maglicco

    Further proof that Consumer Reports is just banter and opinions. You can go out and buy a prius but if you drive it like you stole it you are not gonna meet or exceed the epa estimates.

    Those of us who bought a Cruze (or other vehicles) for their fuel economy are doing fine. Me personally getting over 36mpg combined in my 2012 Cruze and most of that (approx 85%) is city driving. Even with getting on it a few times per tank.

  • EngieKev

    The part that consumer reports is missing is a huge one.  EPA regulation and emissions regulation in general is based on CO2 emission total output.  That value is used in the EPA cycle to calculate the fuel economy from the chassis dyno tests.  It is a very indicative measurement, especially if its intent is to reduce our impact on climate change.  In order to reduce total CO2 engine output, engine displacement must be reduced, there is no way around it.  Turbocharging allows this, you get a lower CO2 output on average at lower speeds/loads, but still have the capability of a much larger NA motor on-tap if needed.  The point is, CR’s “real world” numbers are entirely different than the EPA city in terms of driving cycle, and they have absolutely no merit in making these claims.

  • Jrskipjoe3

    The new Ford 5.0 is called Coyote, The Triton’s are mostly retired, expect in Econoline Vans and Expecdions. Not sure I spelled that right. But the new wave of turbos really don’t get as good as the V-6;s and V-8′s they are replacing. The new Ford Escape with the 1.6 turbo is awfull.

  • VryeDenker

    Try this: cars with smaller turbocharged engines are also usually geared to get the maximum performance out of the engine, hence they rev higher. if you’re driving at 3000rpm in 5th in your little turbo versus 2700rpm in your larger NA car, guess who’s gonna be using more fuel. It’s simple math. In the latter instance, the engine is firing 10% less. That is why it is important to also look at gear ratios and compare like for like.

  • VryeDenker

    Turboes are best at highway speed when they’re actually under boost. If you lose boost at low rpm, you’re basically stuck with a low-compression NA engine.

  • VryeDenker

    I thinks it might be to do with the difference in size between the catalytic converters used in NA and turbocharged engines. I believe the CC in a turbo engine is bigger, hence it neutralises more of the carbon.

  • duh

    Expedition maybe?