Diesels have an edge on gasoline engines when it comes to fuel economy, but compression-ignition engines need extra help to meet America’s emissions regulations. Higher peak-combustion temperatures and pressures produce more oxides of nitrogen than gas engines do. And diesel combustion chambers have fuel-rich pockets that create particulate matter. To explore the varied systems and technologies that scrub diesel exhaust to the government’s satisfaction, we crawled under a 2014 Audi A6 TDI and appropriated the expensive hardware. Then we commenced to slicing. READ MORE ››

The Nest Learning Thermostat and the Nest app are getting better. Again.

We’re pushing out automatic updates to the thermostat and the Nest iOS and Android app over the next few days. The app is getting a full redesign: since you control both Nest Protect and the Nest Learning Thermostat from one place, we updated the mobile app to fit—and work better—for both. You won’t have to turn the phone sideways to set your Thermostat to Away or view settings and things will get a lot more interesting when you connect a Nest Protect. Web control from nest.com has been redesigned to match. We’ve also improved several heating features on the Nest Thermostat to help you save energy this winter.

Software updates go out automatically, so you don’t have to do anything. Once you get the update, you’ll see something like this on your phone:

This example has one Nest Thermostat and one Nest Protect, with room for more.

Pretty much everything you need to know is there at first glance:

• The temperature outdoors, visible on the top left.
• The weather, now with animated clouds, shimmering blue skies or swirls of snow.
• A big button that lets you instantly switch between home and away. No more tilting your phone into landscape mode to set Away manually.
• The temperature you’ve set on your Nest Thermostat. If it’s not currently heating or cooling, the thermostat icon will be black. As heat or AC turns on, it’ll turn orange or blue.
• An icon representing all the Nest Protects in your home. If everything’s ok, you’ll see a green ring. If you’re getting a Heads-Up or Emergency Alarm, the ring will change color to yellow or red.

Tap on the product you want to access—it’ll get bigger, filling the whole screen.

Then tap the Settings icon, now on the top right. For a Nest Thermostat, you’ll see something like this:

You can quickly change from heating to cooling, adjust the fan timer, check Energy History or update your schedule, all without being forced to turn your phone to landscape mode.

As for your Nest Protect smoke alarm (pre-ordered and on its way soon, I hope), there’s a whole app to explore. Tap on the Protect icon and you’ll see something like this:

• Every alarm in your home will be listed by room name, and you’ll be able to quickly scan to see if everything’s ok.
• You’ll see basic status—green, yellow or red—for both smoke and carbon monoxide.
• “Last update” indicates the last time your Nest Protect connected to Wi-Fi, reporting the status of its batteries and sensors. Assuming there’s no emergency, this happens every half hour in a wired Nest Protect and, to save power, every 24 hours in a battery-powered Nest Protect. If there’s a Heads-Up or an emergency, Nest Protect immediately connects to Wi-Fi to update its status and send you a message in the app.
• “Last manual test” refers to the last time you manually tested Nest Protect by pushing the Nest button. We recommend testing monthly—it can be a regular fire drill with your family.
• “Battery life” just tells you if you have to replace your batteries or not.

If something happens—there’s a Heads-Up or Emergency Alarm, or the batteries get low, or even if you need to change your filter—you’ll get a notification in the app.

Here you can see all the messages you’d get about smoke in the living room. First a Heads-Up, then an emergency alarm if the danger escalates, then a notification that the smoke is clearing.

Within Settings, you can turn features on and off. Don’t want Nest Protect to light up at night when you walk underneath it? Just turn off Pathlight.

Of course we realize none of you can see the Nest Protect part of the app until you get a Nest Protect smoke and CO alarm on your ceiling. Luckily, our first Nest Protects are shipping soon.

In the meanwhile, you can check out the 4.0 updates to the Nest Thermostat. The software update going out over the next few days improves a few existing heating features and adds one just to keep things quiet.

You can see if your Nest Thermostat has been updated to 4.0 by checking Technical Info in Settings. You’ll only get certain features if you have certain systems, like dual fuel or heat pump, since Nest tailors its algorithms and features to your home.

• Quiet Time is a brand new 4.0 feature that allows you to set times when noisy stand-alone humidifiers and dehumidifiers won’t turn on, regardless of the humidity. That can keep the house quiet in critical moments, like your kid’s afternoon nap.
• Heat Pump Balance is getting an upgrade, making Balanced and Comfort settings more efficient and using multiple stages of heat for pre-heating.
• Your Nest Thermostat is now smarter about when to switch between fuel types in dual-fuel systems in order to better protect your system and provide more consistent heating.
• Your Nest Protect and Nest Thermostat can now connect to improve the Auto-Away algorithm and shut down your heating system if there’s a CO emergency.

Get all the details about all the updates to the Nest Thermostat here.

We can’t wait for you to try everything together—the Nest Thermostat, Nest Protect, and Nest app. It’s going to be a great winter.

Want to know the fuel economy of a used car, or compare the gas mileage of a used car with a late-model car? The EPA and Department of Energy have released a new tool on the fueleconomy.gov website that will allow you to select your car and see a fuel economy label estimating its city, highway, and combined mpg.

The new label is available to consumers and car dealers, detailing the fuel economy and CO2 emissions for vehicles sold in the United States since 1984. We applaud the move that arms shoppers with more information on the operating cost of a vehicle before purchasing.

Of particular interest, the labels apply fuel economy numbers based on a revised methodology by the EPA, allowing a comparison between new and late-models cars and those built prior to 2008 and tested under a different protocol. The change in the EPA test methodology was to better approximate how cars are currently used, rather than how they were typically driven in the 1970s when the protocol was first introduced. This relatively new approach means that published fuel economy figures generally dropped in 2008, providing a challenge in fairly comparing models. Because these used-car labels are comparable with fuel economy labels on new cars, they provide a better comparison tool for shoppers.

Like new-car labels, this information for used cars includes estimates of how many gallons the cars will consume on a 100-mile trip—a better basis for comparing fuel costs that more dramatically illustrates the differences between cars than a traditional mpg figure

We think used-car buyers should have this information as readily available as new-car buyers and hope that dealerships that sell used cars will adopt the stickers and apply them to all used cars. After all, with some used cars, gas expenses can be greater than monthly payments.

These labels were briefly posted on fueleconomy.gov in 2011, and we are glad to see them finally return. The consumer demand for higher fuel economy only continues to build. The average fuel economy of new vehicles has reached a new high, according to findings from the University of Michigan Transportation Research Institute, underscoring the important of comparable information.

“This action addresses what has been an information gap for used-car buyer,” says Shannon Baker-Branstetter, Policy Counsel for Consumers Union. “If dealerships choose not to take this step to help their customers, Consumers Union will urge the EPA to require them in the future.”

Dealers are able to download and print the labels to apply to cars and use in online ads. Likewise, consumers can visit fueleconomy.gov to research the models on their shopping list.

Consumer Reports publishes our own fuel economy measurements based on cars bought new at dealerships. If you’re buying a used car, you can find our mpg data on previously tested models on the used car overview pages.

See our list of best used cars.

–Eric Evarts

Consumer Reports has no relationship with any advertisers or sponsors on this website. Copyright © 2007-2013 Consumers Union of U.S.

Apple didn’t always get the importance of design. Years before the first iPod, Jony Ive’s budding design team couldn’t get the budget to realize its vision. Exploring how the company went from commodity hardware to having themost iconic designs in the industry, Fast Company is offering up a six-part oral history of Apple’s rise from the people who were actually there. The series wraps up next week, but the first three installments cover OS X's "lickable" Quartz graphics, the conception of the Apple Store, and Steve Jobs' bizarre request that all the company's error messages be haikus.

Speaking about the early days before Steve Jobs’ return in 1996, senior industrial designer Thomas Meyerhoffer says, "We says "we wanted to put design...

Continue reading…

In an effort to give consumers easier access to car recalls, the National Highway Traffic Safety Administration (NHTSA) has announced a rule requiring automakers and motorcycle manufacturers to provide a free online tool to allow recall information to be searched by a Vehicle Identification Number (VIN).

The move will make it easier for consumers to find out immediately whether a vehicle is subject to a recall and if it has received the appropriate fix. This latter function will be helpful for used car shoppers looking to see if the vehicle they want to buy is or was subject to a recall.

Automakers must provide the information on their website and update the data weekly. Some automakers already have the VIN search functionality; others will have until a year from now to comply with the rule.

The search feature will also be available on NHTSA’s website: www.safercar.gov. Currently, car owners can only put in the make and model year of their vehicle, but a VIN search feature will be added.

Also, manufacturers are now mandated to share the type of powertrain and crash avoidance technologies vehicles have with the agency, so NHTSA can look at potential defects, trends, or safety issues related to those systems.

Combined, these measures will better inform consumers and could help raise automotive safety overall.

Consumer Reports currently provides an online tool for car owners to search for recalls by make and model year. There you will find not only the official description, but insights from trained mechanics that explain the recall and its impact.

Recalls can be searched from the main landing page, or browsed from the respective car model page.

–Liza Barth

For more news and articles about cars, subscribe to our feed.

Consumer Reports has no relationship with any advertisers or sponsors on this website. Copyright © 2007-2013 Consumers Union of U.S.