Do You Really Need to Change the Transmission Fluid?

Yes, though how often this service should be performed varies by manufacturer and vehicle, and it's open to debate.

The manufacturer's maintenance schedule for many automatic transmissions doesn't call for fresh fluid until 100,000 miles or, with some Ford transmissions, even 150,000 miles. A lot of mechanics say that is too long and it should be done at least every 50,000 miles. Manual transmissions may be on a different schedule, so it's best to consult the maintenance schedule in the owner's manual.

Like other vital automotive fluids, transmission fluid deteriorates over time. Hard use — such as frequent stop-and-go city driving, hauling heavy loads, trailer towing — will accelerate the deterioration. That kind of driving raises the operating temperature of the transmission, and heat puts more strain on the transmission and the fluid, which helps facilitate gear shifts, cools the transmission and lubricates moving parts.

If you do a lot of driving under high-stress conditions, you should check the transmission level more often and have a repair shop check the condition of the fluid. Transmission fluid often is red but can come in other colors, and as it deteriorates it tends to turn darker. It may also acquire a burned odor that could indicate it needs to be changed or that the transmission is developing mechanical problems. Another indication it needs changing is dirt or other debris in the fluid. When you take your vehicle in for an oil change or other routine service, the repair facility may urge you to pay for a transmission-fluid change or flush. Even if they can show you that the fluid is darker than original, that might not mean you need fresh fluid right now. Step back, check the maintenance schedule in your owner's manual and see what the manufacturer recommends before you decide. This also will give you time to price shop.

Many repair shops use flush systems that force out the old fluid and pump in new fluid. Though that sounds good, some manufacturers say you shouldn't do that (Honda is one; there are others), so you need to know this before you agree to a flush. Look in your owner's manual. Some manufacturers, such as Honda, also call for their own type of transmission fluid and warn that using other types could cause damage. Moreover, some automatic transmissions have filters that should be cleaned or replaced when the fluid is changed. Make sure the repair facility is using the correct fluid and procedures for your vehicle.

If you have never changed the transmission fluid in your vehicle and have more than 100,000 miles on the odometer, should you change it now? We have seen mixed opinions on this, with some mechanics suggesting you should just leave well alone if you aren't having shifting problems. Adding fuel to this theory are stories about older transmissions failing shortly after they finally received fresh fluid. We have a hard time accepting that fresh fluid causes transmission failure, so our inclination would be to have it done if you're planning on keeping the vehicle a few years or longer. However, fresh fluid is not a cure for gears slipping, rough shifting or other mechanical problems, so don't expect a fluid change to be a magic elixir.

2011 Mercedes-Benz E-Class

Price:	$17,999	Vin:	Click Here for VIN
Mileage:	91,171 Miles	Stock #:	1044
Exterior:	Black	Engine:	5.5L V8
Interior:	Gray Leather	Transmission:	Automatic 7-Speed
Trim/Package:		Fuel Type:	Gasoline
MPG City/Hwy:	N/A

How To Properly Check and Fill Tires

While it may seem like a mundane task, inflating tires is much more crucial to your car than you may think, and it results in a safer and more economical experience on the road. Your vehicle's handling also will be greatly improved as the larger a tire's inflated footprint, the more responsive and comfier the ride balance will be.

Because it's National Tire Safety Week, it's the perfect time to check your car's tires.

Before starting

To find your tires' proper inflation level, look for a sticker on the driver-side doorjamb. It displays the vehicle weight restriction and tire information. The info is also found in the maintenance or car-care section of your vehicle’s owner's manual.

Don't refer to the sidewall markings on your tires, which in part specify the maximum tire pressure — not the recommended pressure.

Unless your tire is visibly flat, don't judge tire inflation just by looking at it; you have to use a tire pressure gauge to get the correct pounds per square inch reading. There are three types of tire-pressure gauges: digital, internal slide and dial. Prices range from $5 for a basic gauge to more than $30 for one that is digital, has an air-release button — or even talks. All will do the job, but you may want to consider the conditions in which you'll be using your gauge. "We've found that low-cost digital pressure gauges are very accurate and maintain the accuracy longer, but in extremely cold temperatures the gauge may not show up properly," said John Rastetter, Tire Rack's director of tire information services.



Tips for checking and filling your tires

Tire manufacturers suggest checking tires when they're cold for the most accurate reading. Outside temperatures can cause tire pressure to vary by as much as 1 psi per 10 degrees; higher temperatures mean higher psi readings. "Tires are black; what does black do? Attract heat," Rastetter said, noting the importance of finding a shady place to check and fill all four tires.

Temperature plays a huge part in tire psi, Rastetter said, adding that the most crucial time of year to check pressure is in fall and winter when days are shorter and average temperatures plummet.

Check your tires in the morning before going anywhere, because as soon as you get behind the wheel for an extended amount of time, psi will rise. Rastetter said that if you've been on the road a long time and notice higher psi in your tires, don't let the air out, as the increase in pressure has built up due to the warm, constantly-in-motion tires

What to do

1. Pull your car onto a level surface in the shade.
2. Remove dust caps from the tires' valve stems.
3. Using your tire gauge, firmly press the tip of the gauge straight on to the tire's valve stem for a brief moment.
4. The tire gauge should provide a psi reading; if the number seems unrealistically low or high — for example, 85 psi or 1 psi – you will need to repeat the previous step, ensuring that the tire gauge's tip is properly making contact with the valve stem.
5. If the tire gauge's recorded reading is higher than the manufacturer-recommended rating, press the gauge tip on the valve stem until you hear air leak out. Check the tire pressure again.
6. If the reading is lower than recommended, fill the tire with air by firmly pressing the air-hose tip onto the valve stem. You will hear air quietly enter the tire. If you hear air leaking or spraying out, you need to double-check that the connection between the air hose and the tire’s valve stem is secure.
7. When you think you've added or let out enough air, check the pressure a few times with the gauge.
8. Replace the valve dust caps. Rastetter emphasized the importance of keeping dust caps on during winter driving because if water gets into the valve stem and freezes inside the tire, it could cause a flat.

While you're at it, check your spare tire's pressure. You don't want to have a flat tire and then find out your replacement is flat, too.

Make these steps part of your routine. It will benefit your vehicle and your wallet.

How Often Do I Need to Change My Brake Fluid?

The recommended intervals for changing brake fluid are all over the board depending on the manufacturer, from as often as every two years to never. Really.

For example, Chevrolet says to change the brake fluid on most models every 45,000 miles, but Honda says to do it every three years regardless of the vehicle's mileage. Three years is also the recommended interval for most Volkswagens, but Mercedes-Benz vehicles typically call for fresh fluid every two years or 20,000 miles.

In contrast, on the Ford Escape, Hyundai Elantra, Toyota Camry and other models from those manufacturers, there are no recommendations for replacing the brake fluid, only instructions to inspect it periodically.

This leaves it up to the owner to consult what the manufacturer says in their car's maintenance schedule and rely on the advice of a trusted repair shop.

Brake fluid lives in a sealed system and can survive for years, but moisture from the surrounding air can work its way in through hoses and other parts of the brake system. Water in the brake lines lowers the boiling point of the fluid, so stopping ability can diminish in hard stops as heat in the system increases. In addition, over time the moisture can cause internal corrosion in the brake lines, calipers, the master cylinder and other components.

Flushing and replacing brake fluid might cost $100 or less on many vehicles, but replacing rusted brake lines and other parts can run several hundreds of dollars, so clearly there's value in keeping up with maintenance.

As a rule of thumb, it's wise to have the brake fluid inspected and perhaps tested for moisture content every few years and no more than every five if you live in a high-humidity area.

You might be able to tell it's time for a change by looking to see if the fluid is still fresh. Brake fluid is often light brown in color, but in some vehicles it's clear (at least when new) and will darken with age, becoming murky from water contamination. A better way is to have it tested by a professional for moisture and see what they recommend.

Brake fluid is as vital to stopping a vehicle as engine oil is to keeping it going, but it doesn't get as much attention as it deserves.

How Long Does a Car Battery in a New Car Last?

Though battery problems are often associated with cold weather, Consumer Reports magazine says heat is a bigger enemy of car batteries and will take a bigger toll on performance and reserve capacity. The magazine recommends that vehicle owners in hotter parts of the country have their car battery tested after two years of ownership and then every year after. Those who live in colder areas can wait four years to test performance and capacity, and then every year after.

"Heat kills batteries," according to John Banta, a Consumer Reports project leader and part of the team that tests batteries for the magazine. "Many times in cold climates your battery fails to start your car on a below-freezing day. The reason this happens is that the heat of the past summers has weakened your battery. When you use it in the cold, the starter requires more electrical current to turn over the cold engine with its thickened oil."

Testing a battery's performance and reserve (or amp-hour) capacity is not just a matter of seeing whether it will hold a charge (or checking the electric eye found on some batteries to see if it is green), so testing is best done by an auto technician.

Does My Car Need Synthetic Oil?

If your car's owner's manual says it does, you do.

For many consumers, whether to spend extra money for synthetic oil for an oil change is a difficult question to answer.

Manufacturers of synthetic oil promise more miles and better performance when compared with conventional motor oil, but it comes at a higher cost — sometimes twice as much per oil change. Is it worth the extra money?

Typically, high-performance vehicles will be more likely to require synthetic oil, as will vehicles that have a turbocharged or supercharged engine. However, if your vehicle does not require synthetic oil, the choice is trickier - and there is no clear answer.

Synthetic oil generally resists breaking down for longer than conventional motor oil (typically 7,500 miles to 10,000 miles, sometimes up to 15,000 miles, as opposed to 3,000 miles to 7,500 miles for conventional oil). That makes the extra cost a wash, if you have half the number of oil changes, but each one costs you twice as much. Other touted benefits include cleaner engines, better flow in cold temperatures, better protection when it's hot outside and better performance with turbocharged engines.

There are also synthetic blends. As the name implies, these are blends of synthetic and conventional oils. They straddle a middle ground — they cost more than conventional oils but less than full synthetics, and are said to last longer than conventional oils but not quite as long as synthetics — but again, that's a hard number to pin down since manufacturers are vague with their claims. An independent testing lab we spoke with said that synthetics often didn't perform much better than conventional oils do.

Still, older engines may benefit from synthetics because it is less likely to form sludge.

If your car doesn't require synthetic oil you should perform a cost/benefit analysis, but that can be difficult to do due to vague claims made by manufacturers. There may be no reason to spend more on synthetic oil, except for peace of mind.

Does My Car Need Synthetic Oil?

If your car's owner's manual says it does, you do.

For many consumers, whether to spend extra money for synthetic oil for an oil change is a difficult question to answer.

Manufacturers of synthetic oil promise more miles and better performance when compared with conventional motor oil, but it comes at a higher cost — sometimes twice as much per oil change. Is it worth the extra money?

Typically, high-performance vehicles will be more likely to require synthetic oil, as will vehicles that have a turbocharged or supercharged engine. However, if your vehicle does not require synthetic oil, the choice is trickier - and there is no clear answer.

Synthetic oil generally resists breaking down for longer than conventional motor oil (typically 7,500 miles to 10,000 miles, sometimes up to 15,000 miles, as opposed to 3,000 miles to 7,500 miles for conventional oil). That makes the extra cost a wash, if you have half the number of oil changes, but each one costs you twice as much. Other touted benefits include cleaner engines, better flow in cold temperatures, better protection when it's hot outside and better performance with turbocharged engines.

There are also synthetic blends. As the name implies, these are blends of synthetic and conventional oils. They straddle a middle ground — they cost more than conventional oils but less than full synthetics, and are said to last longer than conventional oils but not quite as long as synthetics — but again, that's a hard number to pin down since manufacturers are vague with their claims. An independent testing lab we spoke with said that synthetics often didn't perform much better than conventional oils do.

Still, older engines may benefit from synthetics because it is less likely to form sludge.

If your car doesn't require synthetic oil you should perform a cost/benefit analysis, but that can be difficult to do due to vague claims made by manufacturers. There may be no reason to spend more on synthetic oil, except for peace of mind.