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Q: My 2010 Subaru Forester needs a catalytic converter. The car is from California and has a California-compliant converter. But I don't live there. Do I have to replace it with a similar unit, or can I use one that's good in all the other states?

A: Vehicles certified to California emission standards meet more stringent standards for hydrocarbons (HC), nitrogen oxides (NOx) and carbon monoxide (CO) than vehicles certified to the federal standards. And even though the vehicle no longer is in California, its engine management system is calibrated for that unit.

Short answer? Yes, you should install a similar one.

Bulletins move to internet

Q: Why are manufacturers' technical service bulletins no longer public domain? I always learned something about my vehicle from reading them.

A: Most of the information still is available. Most likely, you're just looking in the wrong place. You can find free summaries of many technical service bulletins (along with details about safety investigations, complaints and other information) by entering your vehicle's year, make and model at SaferCar.gov and clicking on the "Service Bulletins" tab.

Tire pressures

Q: In 2015, I purchased a 2015 BMW 328i. During an oil change at 19,500 miles, the dealer recommended I replace the tires because of tread wear. I asked why they needed replacement at such a low mileage. I was told that it comes down to how you drive, but I only drive conservatively around town and at the posted speed limits.

Then, my wife's 2017 Acura RDX, which was at 21,000 miles, needed the tires replaced. Is it unreasonable to expect tires to last more than 20,000 miles? I would have expected up to 40,000 miles.

A: Driving habits are a key factor in tread life, but if you are a timid traveler, let's rule that out. You didn't mention the type of tires on your cars. I have a hunch they are performance models that do not wear well. The next time you buy tires, have a talk with the people at the store. They should be able to suggest a longer-lasting model with a higher wear rating.

To dye for

Q: A friend of mine changes his own brake fluid. Before he sends new fluid to each wheel, he puts a small amount of food coloring in the master cylinder. He says that by doing this, he can make sure that new fluid has gotten to each wheel.

He has been doing this for many years and says there has never been a problem. Do you think this is a good idea?

A: I would not advise it. Food coloring is water-based, and water doesn't mix with hydraulics. The water can boil and vaporize from the heat generated during braking. Vapor can be compressed, which would cause the brakes to fade.

Bob Weber is a writer, mechanic and ASE-certified Master Automobile Technician. His writing has appeared in automotive trade publications, Consumer Guide and Consumers Digest. Send automotive questions along with name and town to motormouth.tribune@gmail.com.