2009 SEMA Show: New iPhone apps for auto diagnostics

New iPhone apps seem to be appearing daily in the Apple iTunes store, if not by the minute or even second, and car-related ways to utilize the popular convergence device are no exception. (See our iPhone navigation application reviews.)

Two exhibitors at the Specialty Equipment Manufacturers Association (SEMA) show brought devices that can turn an iPhone or iPod Touch into a vehicle diagnostic tool, maintenance minder, mpg meter, and provide performance-oriented drivers with customized gauges and track mapping for weekend racers. In fact, they offer many additional features, too numerous to list here.
 
The Kiwi Wifi from PLX devices and goLINK Protocol Converter both connect to the On-Board Diagnostics II (OBDII) system in your car to transmit all sorts of vehicle data and information. The big difference is the Kiwi Wifi (you guessed it) transmits the information to the phone wirelessly, and goLINK uses a cable to link directly to the iPhone. Both are compatible with passenger vehicles built after 1996.
 
The Kiwi Wifi and goLINK offer similar menus for iPhone users, partly because they work with some of the same software providers. They’re also priced the same, at $150 each. A number of add-on software options are available at the Apple apps store to take advantage of the connection. One such app is Rev by Devtoaster ($39.99), which records and displays real-time vehicle data like horsepower, torque, fuel consumption, and myriad powertrain details to aid tuners and racers (shown here).
 
The Kiwi Wifi module is available now. The goLINK device comes on the market in January 2010. Details can be found at gopointtech.com and plxdevices.com.

—Jim Travers with Liza Barth

Also see from the 2009 SEMA show:
Better than expected, future looks greener
Tire testing and the transformation of the tire industry
Our favorite modified Chevrolet Camaros
World's fastest Honda Civic circa 1976
All shades of green project cars
Surfrider Toyota Camry hybrid CNG
Kustomizing the Toyota Prius
Hot rodders turning green
Auto aftermarket prepares for show time in Las Vegas

Tires Q&A: Tire rolling resistance

In our ongoing series of Q&A blog columns, we will highlight common and interesting questions posted to our Car forums, with answers from our automotive experts.

Question: I bought four Yokohama Avid TRZ tires just two weeks before the 11/09 Consumer Reports issue arrived. I'd read reviews on the internet but none addressed mileage. As I drive an ‘04 Prius, mileage is very important. I had been trying to figure how new tires would drop my mileage a very noticeable 10 percent (from 53.3 to 48). Had I only known the tire ratings were coming I would gladly have waited and would definitely have different tires today.

Answer: I’m sorry the report did not reach you in time of your tire purchase. Until the State of California or the federal government comes out with rolling resistance regulations and ratings, your only sources for rolling resistance information on tires are from manufacturers’ claims and Consumer Reports. Our testing is comparative among the models tested.

Yes, you could have purchased a more fuel-efficient tire, but the Yokohama Avid TRZ is average among all season replacement tires for rolling resistance. Some were better--such as the top-rated Michelin HydroEdge, and the Toyo Versado LX. One point to consider when replacing tires: As tires wear out, you’ll likely see improved fuel economy since the tires will have less rolling resistance as the tread (mass) is removed from the tire. Installing new tires, identical in brand and model as those removed, and you likely see a reduction in your fuel economy. The new TRZ tires should become more fuel efficient as the tires wear. Also, keep the tires properly inflated and check them monthly to get the optimum fuel efficiency.

To see full details on the tire models we tested, check out our Ratings and recommendations (available to subscribers). In addition to our updated Ratings, all site visitors can access our free buying advice for tips on getting started, types of tires we test, features that are important in making a tire purchase, and general tire care. Also, be sure to check out our TireTalk forum to interact with our tire engineers and other drivers.

—Gene Petersen 

Tires Q&A: Tire-testing vehicles

In our ongoing series of Q&A blog columns, we will highlight common and interesting questions posted to our Car forums, with answers from our automotive experts.

Question: Has CR tried using different cars, but same size tires to see if the relative ranking would change dramatically?

Answer: Our tests are designed to judge tire performance on a comparative basis. Our goal is to use a popular and suitable car and appropriate tire size that also best represents the segment we are evaluating. Hence, we use one car or truck as the test calls for.

From our experience, a car’s natural abilities in terms of handling and ride comfort would influence the results, but it would be an offset in the comparative ratings between one car model to another. Also, differences in vehicle weight, wheel alignment, and drive-wheel configuration could affect a number of tests like snow traction, ice braking, and hydroplaning resistance. But, again, the comparative results should be maintained. The same holds true for our tread life test that’s done on like vehicles under identical conditions and is strictly a comparative test. Rolling resistance is the only test done without a car, performed on a dynamometer, so there is no vehicle effect.

More recently we have seen stopping distance reversals of tire models when used on different cars. This generally happens with tire models that are somewhat close in braking performance, and our data suggests a grippy tire is generally good on a wide variety of cars. But today’s cars have ABS brake systems tuned to a specific peak friction characteristic. To judge the tire’s peak level of grip we now do a “best effort” stop on dry and wet surfaces. A best effort stop has the driver modulate the brake pedal effort to get the shortest stop without wheel lockup, evaluating each tire model to its own peak friction level.

Comparative testing works well if you can remove or compensate for the vehicle effects as we strive to do. Publishing actual data would be misleading because it applies to the specific vehicle used.

Ratings, recommendations and buying advice on car, truck and winter tires, see our tires section.

—Gene Petersen  

Video: How to choose the best tires

At a glance, all tires look alike. They are black, round, and ringed with tread patterns. But there are significant differences in how they perform and how they wear. Since tires are the only part of the car that touches the road, it is crucial that you make a smart, informed decision about what tire is right for you. And we can help.

As demonstrated in this tire buying video, Consumer Reports runs a comprehensive, year-round tire testing program to ensure it can deliver the advice and ratings you need. To evaluate all aspects of a tire, we put it through a number of objective and subjective tests in the most comprehensive tire-test program of any American magazine or Web site.

We test braking and lateral grip on dry and wet surfaces, handling in our emergency-avoidance maneuver, and hydroplaning resistance, which measures how well a tire maintains contact with the road in standing water. We evaluate how easily a tire can accelerate on moderately packed snow and we rent a local skating rink to test braking on ice. Outside labs evaluate tread life and rolling resistance which is a function fuel efficiency . To ensure consistency, we buy each tire model in the same size and mount them on the same test cars.

Check out our video to see the details on how we conduct these tests. Then see our car, SUV and truck, and winter tire ratings (available to subscribers) to find the models that score well in the areas that matter most to you. All site visitors can access our free buying advice for tips on getting started, types of tires we test, features that are important in making a tire purchase, and general tire care. Also, be sure to check out our TireTalk forum to interact with our tire engineers and other drivers.

—Liza Barth 

Car care: Myths vs. reality

When it comes to maintaining your car, misconceptions abound. And even the best intentions can lead you to spend more money than necessary or even compromise your safety. Here are a few common car care myths that can do more harm than good.

Myth: Engine oil should be changed every 3,000 miles.

Reality: Despite what oil companies and quick-lube shops often claim, it’s usually not necessary. Stick to the service intervals in your car’s owner’s manual. Under normal driving conditions, most vehicles are designed to go 7,500 miles or more between oil changes. Changing oil more often doesn’t hurt the engine, but it can cost you a lot of extra money. Automakers often recommend 3,000-mile intervals for severe driving conditions, such as constant stop-and-go driving, frequent trailer-towing, mountainous terrain, or dusty conditions. Read how to check your car's engine oil.

Myth: Inflate tires to the pressure shown on the tire’s sidewall.

Reality: The pounds-per-square-inch figure on the side of the tire is the maximum pressure that the tire can safely hold, not the automaker’s recommended pressure, which provides the best balance of braking, handling, gas mileage, and ride comfort. That figure is usually found on a doorjamb sticker, in the glove box, or on the fuel-filler door. Perform a monthly pressure check when tires are cold or after the car has been parked for a few hours. See our tips on tire maintenance.

Myth: If regular-grade fuel is good, premium must be better.

Reality: Most vehicles run just fine on regular-grade (87 octane) fuel. Using premium in these cars won’t hurt, but it won’t improve performance, either. A higher-octane number simply means that the fuel is less prone to pre-ignition problems, so it’s often specified for hotter running, high-compression engines. So if your car is designed for 87-octane fuel, don’t waste money on premium. (Read more on how to get the best gas mileage.)

Myth: After a jump-start, your car will soon recharge the battery.

Reality: It could take hours of driving to restore a battery’s full charge, especially in the winter. That’s because power accessories, such as heated seats, draw so much electricity that in some cars the alternator has little left over to recharge a run-down battery. A “load test” at a service station can determine whether the battery can still hold a charge. If so, some hours on a battery charger might be needed to revive the battery to its full potential. (See our car battery ratings and buying advice.)

Myth: Let your engine warm up for several minutes before driving.

Reality: That might have been good advice for yesteryear’s cars but is less so today. Modern engines warm up more quickly when they’re driven. And the sooner they warm up, the sooner they reach maximum efficiency and deliver the best fuel economy and performance. But don’t rev the engine high over the first few miles while it’s warming up.

Myth: A dealership must perform regular maintenance to keep your car’s factory warranty valid.

Reality: As long as the maintenance items specified in the vehicle owner’s manual are performed on schedule, the work can be done at any auto-repair shop. If you’re knowledgeable, you can even do the work yourself. Just keep accurate records and receipts to back you up in case of a warranty dispute on a future repair.

For more on taking care of your car, see our guide to car maintenance.  Talk with others about car maintenance and repair in John's Tool Box forum.

H-rated tires with shorter life spans become more common

Consumer Reports runs the largest tire testing program in the United States. And one of the main things we’ve found in our testing lately is that keeping fresh tires on your car is getting more expensive.

One reason for the increased cost for rolling stock is that more and more family cars are coming equipped with higher-speed rated tires. Speed ratings indicate the highest speed a tire maker considers safe for that tire to travel and is designated by letters such as Q, S, T, H, V, and Z along with the tire size information on the sidewall. All these ratings cover speeds well above legal limits. The most popular, S, T, and H, are rated for 112, 118, and 130 mph, respectively.

Traditionally, most family cars have used S- and T-rated tires, while tires rated H and higher have mostly been available only in sports cars or upscale sports sedans. But when we tested this year’s group of all-season passenger-car tires, we found a growing number of popular cars are equipped from the factory with H-speed rated tires. Partially, this is because tire manufacturers have an easier time meeting the latest tire safety standards with higher speed-rated tires. Other factors include using performance tires that are better suited to the elevated levels of acceleration, braking, and handling that todays family cars are capable of achieving, and finally, marketing is driving the move to squatting low profile performance tires.

So what should drivers do?

A key lesson here is to be aware of the tires on the vehicles you are considering purchasing. Not only have speed-ratings increased since your last purchase, but so have the overall size. There are family vehicles now, such as the Toyota Venza, that are available with 20-inch wheel diameters—a size considered exotic just a few years ago. Carefully consider the benefits of upsizing the wheels when you buy the car, either from the factory or with aftermarket wheels.

Most vehicles are available with a choice of fitment, often characterized as a base tire/wheel combination and a sportier option. Often the more aggressive tire/wheel combination will enhancing traction and even give the car a more sporty feel, with heavier steering and greater road feedback. However, such upgrades often lead to compromises with a harsher ride and shorter tread life, plus a greater upfront cost. The lesson here is to think twice before upgrading the rubber on your new car.

For owners looking at tire replacement, we don’t recommend downgrading because it introduces a safety risk. Tires with higher speed ratings generally have better steering response and cornering grip than lower-speed rated tires, in addition to being capable of higher speeds. So if your car originally came with H-rated tires, that’s what you should replace them with. After all, the automaker spent millions on testing the car with that specific configuration, including suspension and braking systems.

Sticking with H-rated tires comes at a cost. While we found prices are similar to S- and T-rated tires, H-rated tires didn’t last as long in our treadwear test--an average of 49,180 miles, versus 61,080 for our S- and T-rated tires. V-rated tires had an even shorter tread life of 48,260 miles. Mileages are projected to wear-out, based on Consumer Report 16,000 mile wear tests.

While the speed ratings are one more factor to consider in your next vehicle purchase, it is better to be armed with the information before having to visit the tire store earlier than expected.

To find the best tires for your car, check out our tire ratings (for subscribers). Or check out our general advice on tire safety and shopping for tires.

—Eric Evarts

New tire tests and Ratings

Michelin tires top four categories in our latest Ratings of 69 models of all-season (S and T speed ratings), performance all-season (H and V speed ratings) and Winter tires--the largest group ever tested by Consumer Reports.

The Michelin HydroEdge was the top scoring model among S- and T-rated all-season tires, and the Michelin Primacy MXV4 and Michelin Pilot Exalto A/S took top honors among H- and V-rated all-seasons, respectively. The Michelin X-Ice XI 2 topped CR's ratings for winter tires for passenger cars.

CR's tire engineers rated models based on a variety of categories including dry and wet braking, handling, hydroplaning resistance, snow traction, ice braking, ride comfort, noise, rolling resistance, and tread life. Despite top scores, the Michelin models aren't necessarily the best in every area and they are also among the most expensive tires CR tested, but drivers don't have to pay top dollar to get good performance.

Other high scoring all season tires include the Hankook Optimo H727, Nokian WR G2, Dunlop Signature in the all season and H and V speed rated all season categories, respectively. In the winter category, the General Altimax Arctic was a runner-up to the Michelin X-Ice XI 2.

Consumer Reports' testers put tires through a number of objective and subjective tests. Testers measure braking and lateral grip on dry and wet surfaces, handling in CR's emergency avoidance maneuver, and hydroplaning resistance, which measures how well a tire maintains contact with the road in standing water. CR rents a local skating rink to test braking on ice and has outside labs evaluate tread life and rolling resistance. To ensure consistency, testers buy each tire model in the same size and mount them on the same test cars.

CR's latest tire ratings have changed from previous tests. Starting with these tests, CR's ratings are now designed so that readers can compare the individual performance of one type of tire with another. For example, you can compare the ratings of all-season and winter tires to see how much dry and wet grip you give up with winter tires in return for better snow and ice traction. The overall score, however, is still relative to each tire category. Because tread life can influence driving safety, a tread-life rating is included in each tire's overall score.

Investing in better tires can give you a wider margin of safety when driving. A little extra grip, for example, can mean the difference between an accident and a close call. There are a lot of tire choices, and you can't tell by looking at them which ones will perform better. When you buy replacement tires, CR recommends sticking with the same size and speed rating of your car's original tires. You can find the specifications listed on a placard usually located inside the driver's doorjamb.

To see full details on the tire models we tested, check out our Ratings and recommendations (available to subscribers). In addition to our updated Ratings, all site visitors can access our free buying advice for tips on getting started, types of tires we test, features that are important in making a tire purchase, and general tire care. Also, be sure to check out our TireTalk forum to interact with our tire engineers and other drivers.

Tires Q&A: Run-flat tires for Corvette?

In our ongoing series of Q&A blog columns, we will highlight common and interesting questions posted to our Car forums, with answers from our automotive experts.

Question: My first Corvette has Michelin Pilot Sport A/S Plus. I’m considering using the same tires but in a run flat, but I hear bad things about them. Any feedback would be appreciated.

Answer: In short, the virtue of a run-flat tire is extended mobility with no need to worry about being stranded with a flat tire. If you have my luck, the tire will go flat on a rainy, cold night over a dangerous section of road--and you don’t get to choose when a tire goes flat. Run-flat tires can handle a puncture or road-inflicted damage and allow the driver to make it to a service station or final destination. That’s the payoff of having run-flat tires.

Our experience is that some applications work better than others. The Corvette C5 is a perfect candidate for run-flat tires as there’s not much room for a spare tire, let alone room for tossing in a full-size flat tire inside the car. Run-flat tires are stiff by design to support the weight of the vehicle with no air pressure. For the Corvette, which uses stiff, low-profile ultra high performance tires, a run-flat is not much of a trade-off in terms of ride comfort and handling, even when it goes flat. Also, the Corvette was designed to accommodate run-flat tires, so it should be your first consideration when making a new tire purchase.

See our run-flat report to learn more about on the pros and cons of run-flat tires. For Ratings, recommendations and buying advice on car, truck and winter tires, see our tires section.

—Gene Petersen 

Tires Q&A: Problem solving irregular wear

In our ongoing series of Q&A blog columns, we will highlight common and interesting questions posted to our Car forums, with answers from our automotive experts.

Question: My Mazda RX-8 is showing tread wear on the outer edges of the tire. Wheel balance, right? Wrong. I paid $50 to find out that all the wheels are within specs. I consistently keep the inflation between 32-34 lbs so that can't be it. The shop guy said "bad tires." They are original Bridgestone Potenzas. Could he be right? I don't know where to turn next.

Answer: Tire wear issues like that mentioned above are all too common and often the blame goes to the tire manufacturer if there is no apparent easy answer. That’s too bad since it can be avoidable most of the time. Most experienced tire dealers can diagnose the problem just like a doctor does with a patient – mostly by observing and narrowing down the possibilities.

In this case, the tire wear pattern tells the story. The fast outside shoulder wear suggests a wheel mis-alignment. The owner said that the tires received an alignment, which was deemed in-spec but not on-spec. Often that might not be good enough for some cars and the owner and consumers alike should request that wheel alignment be adjusted back to the middle of the alignment specification or as close as possible. In other words, sometimes “close-enough” isn’t good enough. The RX-8 owner isn’t alone. We just recently examined a police cruiser that had a similar wear problem. The officer had the cruiser checked for alignment and was told it was within tolerance but not to the exact specification. Ironically, the alignment shop told the officer that the tires were probably the problem and replaced them. Guess what? The new tires were starting to wear like the old ones. We told the officer to have the wheels re-aligned to the exact specification and to have the shop check for any worn suspension components while they were at it.

Bottom line: Sometimes you have to be persistent. The red flag in both examples was that the alignment was checked, but the shop didn’t put the effort into re-aligning the car to the exact specification. Look at your tires, particularly their wear, as they can tell the story.

—Gene Petersen

Fall cleanup for your car

With the official end of summer, it’s now time to start thinking about getting your car ready for the colder months ahead. Here are a few simple maintenance checks to help keep your vehicle in top condition.

Wipers: If your wipers are leaving streaks of water on your windshield, then it’s time to replace them—or clean them. Wipers degrade quickly and typically need to be changed every 6-12 months. Should performance deteriorate in less time, try cleaning the blade with a paper towel and glass cleaner. Often, this can renew the blades for a few more weeks or months of streak-free operation. For Ratings and advice, see our windshield wiper report. 

Tires: Proper maintenance and responsible driving can maximize the mileage in a set of tires. Monthly tread inspections can inform when the tires warrant replacement. If you notice that your tires have less than 1/8-inch of tread left, then it’s time to go shopping. (The distance from a quarter's rim to George Washington's hairline is about 1/8 inch.) Check out our new tire ratings and buying advice for all-season, truck, and winter tires. 

Batteries: Fall is a good time to inspect your battery, making sure the cables and terminals are snug and retighten as necessary for good contact. If your connections are dirty or showing a lot of corrosion, disconnect and clean them with a wire brush or cleaning tool. Be aware that when you disconnect the battery, you may have to re-enter a security code in your radio or navigation system. If you have a sealed, maintenance-free battery with no removable caps, there's little else you need to do. If your battery has removable caps, check the water level periodically, and refill with distilled water as needed. Finally, if the vehicle is going to be parked or stored for an extended period of time, you may want to consider investing in a trickle charger to keep it charged. All batteries lose strength over time, so it’s prudent to be proactive in replacing your battery. Batteries come in a variety of sizes and it's important to choose the right size. Check your owner’s manual or in-store guide, then check our battery Ratings and buying advice to choose the right ones for your needs. 

Wash and wax: Fall is a good time to clean up your car, so winter’s mess doesn’t land on top of the summer’s dead bugs, bird droppings, and tree sap. If you want to go further than soap and water, you can try car wax to keep your car’s finish looking new. See our dos and don’ts of car washing for more tips. 

For more advice on tidying up your car, home, electronics, health, and more see our fall cleanup guide.

 —Liza Barth